Category Archives: Climate Change

WE MUST ACT NOW! IPCC Special Report 2018. Global Warming of 1.5°C, The Impact.

Current nationally stated mitigation ambitions until 2030 will result in a global warming of about 3°C by 2100, with warming continuing afterwards.

Limiting global warming to 1.5°C requires rapid and far reaching transitions in energy, land, urban and infrastructure, including transport and buildings, and industrial systems.

Social justice and equity are core aspects of climate-resilient development pathways that aim to limit global warming to 1.5°C.

An IPCC special report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty.

Introduction

This Report responds to the invitation for IPCC to provide a Special Report in 2018 on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways contained in the Decision of the 21st Conference of Parties of the United Nations Framework Convention on Climate Change to adopt the Paris Agreement.

The IPCC accepted the invitation in April 2016, deciding to prepare this Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty.

This Summary for Policymakers (SPM) presents the key findings of the Special Report, based on the assessment of the available scientific, technical and socio-economic literature relevant to global warming of 1.5°C and for the comparison between global warming of 1.5°C and 2°C above pre-industrial levels.

Core Concepts Central to this Special Report

Global mean surface temperature (GMST): Estimated global average of near-surface air temperatures over land and sea ice, and sea surface temperatures over ice-free ocean regions, wrth changes normally expressed as departures from a value over a specified reference period. When estimating changes in GMST, near-surtace air temperature over both land and oceans are also used.

Pre industrial: The multi century period prior to the onset of large scale industrial activity around 1850. The reference period 1850-1900 is used to approximate pre-industrial GMST.

Global warming: The estimated increase in GMST averaged over a 30-year period, or the 30-year period centred on a particuiar year or decade, expressed relative to pre-industrial levels unless otherwise specified. For 30-year periods that span past and future years, the current multi-decadal warming trend is assumed to continue.

Net zero C02 emissions: Net zero carbon dioxide (CO2) emissions are achieved when anthropogenic C02 emissions are balanced globally by anthropogenic C02 removals over a specified period.

Carbon dioxide removal (CDR): Anthropogenic activities removing CO2 from the atmosphere and durably storing it in geological, terrestrial, or ocean reservoirs, or in products. It includes existing and potential anthropogenic enhancement of biological or geochemical sinks and direct air capture and storage, but excludes natural C02 uptake not directly caused by human activities.

Total carbon budget: Estimated cumulative net global anthropogenic C02 emissions from the pre-industrial period to the time that anthropogenic C02 emissions reach net zero that would result, at some probability, in limiting global warming to a given level, accounting for the impact of other anthropogenic emissions.

Remaining carbon budget: Estimated cumulative net global anthropogenic CO2 emissions from a given start date to the time that anthropogenic C02 emissions reach net zero that would result, at some probability, in limiting global warming to a given level, accounting for the impact of other anthropogenic emissions.

Temperature overshoot: The temporary exceedance of a specified level of global warming.

Emission pathways: In this Summary for Policymakers, the modelled trajectories of global anthropogenic emissions over the 21st century are termed emission pathways. Emission pathways are classified by their temperature trajectory over the last century: pathways giving at least 50% probability based on current knowledge of limiting global warming to below 1.5°C are classified as ‘no overshoot’; those limiting warming to below 1.6°C and returning to 1.5°C by 2100 are classified as ‘1.5°C limited overshoot’; while those exceeding 1.6°C but still returning to 1.5°C by 2100 are classified as ‘higher overshoot’.

Impacts: Effects of climate change on human and natural systems. Impacts can have beneficial or adverse outcomes for livelihoods, health and well-being, ecosystems and species, services, infrastructure, and economic, social and cultural assets.

Risk: The potential for adverse consequences from a climate related hazard for human and natural systems, resulting from the interactions between the hazard and the vulnerability and exposure of the affected system. Risk integrates the likelihood of exposure to a hazard and the magnitude of its impact. Risk also can describe the potential for adverse consequences of adaptation or mitigation responses to climate change.

Climate-resilient development pathways (CRDPs): Trajectories that strengthen sustainable development at multiple scales and efforts to eradicate poverty through equitable societal and systems transitions and transformations while reducing the threat of climate change through ambltious mitigation, adaptation and climate resilience.

Understanding Global Warming of 1.5°C

Human activities are estimated to have caused approximately 1.0°C of global warming above pre industrial levels, with a likely range of 0.8°C to 1.2°C. Global warming is likely to reach 1.5°C between 2030 and 2052 if it continues to increase at the current rate.

Reflecting the long term warming trend since pre industrial times, observed global mean surface temperature (GMST) for the decade 2006-2015 was 0.87°C (likely between 075°C and 099°C) higher than the average over the 1850-1900 period. Estimated anthropogenic global warming matches the level of observed warming to within 120% (likely range). Estimated anthropogenic global warming is currently increasing at 0.2°C (likely between 0.1°C and 0.3°C) per decade due to past and ongoing emissions.

Radiative forcing or climate forcing is the difference between insolation (sunlight) absorbed by the Earth and energy radiated back to space. The influences that cause changes to the Earth’s climate system altering Earth’s radiative equilibrium, forcing temperatures to rise or fall, are called climate forcings. Positive radiative forcing means Earth receives more incoming energy from sunlight than it radiates to space. This net gain of energy will cause warming. Conversely, negative radiative forcing means that Earth loses more energy to space than it receives from the sun, which produces cooling.

Warming greater than the global annual average is being experienced in many land regions and seasons, including two to three times higher in the Arctic. Warming is generally higher over land than over the ocean.

Trends in intensity and frequency of some climate and weather extremes have been detected over time spans during which about 0.5°C of global warming occurred.

This assessment is based on several lines of evidence, including attribution studies for changes in extremes since 1950.

Warming from anthropogenic emissions from the pre industrial period to the present will persist for centuries to millennia and will continue to cause further long term changes in the climate system, such as sea level rise, with associated impacts, but these emissions alone are unlikely to cause global warming of 1.5°C.

Anthropogenic emissions (including greenhouse gases, aerosols and their precursors) up to the present are unlikely to cause further warming of more than 0.5°C over the next two to three decades or on a century time scale.

Reaching and sustaining net zero global anthropogenic C02 emissions and declining net non-CO2 radiative forcing would halt anthropogenic global warming on multi-decadal time scales. The maximum temperature reached is then determined by cumulative net global anthropogenic CO2 emissions up to the time of net zero CO2 emissions and the level of non-CO2 radiative forcing in the decades prior to the time that maximum temperatures are reached. 0n longer time scales, sustained net negative global anthropogenic C02 emissions and/or further reductions in non-CO2 radiative forcing may still be required to prevent further warming due to Earth system feedbacks and to reverse ocean acidification and will be required to minimize sea level rise.

Climate-related risks for natural and human systems are higher for global warming of 1.5°C than at present, but lower than at 2°C. These risks depend on the magnitude and rate of warming, geographic location, levels of development and vulnerability, and on the choices and implementation of adaptation and mitigation options.

Impacts on natural and human systems from global warming have already been observed. Many land and ocean ecosystems and some of the services they provide have already changed due to global warming.

Future climate-related risks depend on the rate, peak and duration of warming. In the aggregate, they are larger if global warming exceeds 1.5°C before returning to that level by 2100 than if global warming gradually stabilizes at 1.5°C, especially if the peak temperature is high (e.g., about 2°C). Some impacts may be long-lasting or ireversible, such as the loss of some ecosystems.

Adaptation and mitigation are already occurring. Future climate-related risks would be reduced by the upscaling and acceleration of far reaching, multilevel and cross-sectoral climate mitigation and by both incremental and transformational adaptation.

Figure SPM.1 Panel a: Observed monthly global mean surface temperature (GMST, grey line up to 2017, from the HadCRUTA, GISTEMP, Cowtan-Way, and NCAA datasets) change and estimated anthropogenic global warming (Solid orange line up to 2017, with orange shading indicating assessed likely range). Orange dashed arrow and horizontal orange error bar show respectively the central estimate and likely range of the time at which 1.5°C is reached if the current rate of warming continues. The grey plume on the right of panel a shows the likely range of warming responses, computed with a simple climate model, to a stylized pathway (hypothetical future) in which net C02 emissions (grey lines in panels b and c) decline in a straight line from 2020 to reach net zero in 2055 and net non-C02 radiative forcing (grey line in panel d) increases to 2030 and then declining. The blue plume in panel a) shows the response to faster CO2 emissiins reductions (blue line in panel b), reaching net zero in 2040, reducmg cumulative C02 emissions (panel c). The purple plume shows the response to net CO2 emissions declining to zero in 2055, with net non-CO2 forcing remaining constant after 2030. The vertical error bars on right of panel a) show the likely ranges (thin lines) and central terciles (33rd – 66th percentiles, thick lines) of the estimated distribution of warming in 2100 under these three stylzed pathways. Vertical dotted error bars in panels b, c and d show the likely range of historical annual and cumulative global net CO2 emissions In 2017 (data from the Global Carbon Preject) and of net non-CO2 radiative forcing in 2011 from AR5, respectlvely. Vertical axes in panels c and d are scaled to represent approximately equal effects on GMST.

Projected Climate Change, Potential Impacts and Associated Risks

Climate models project robust differences in regional climate characteristics between present day and global warming of 1.5°C, and between 1.5°C and 2°C. These differences include increases in: mean temperature in most land and ocean regions, hot extremes in most inhabited regions, heavy precipitation in several regions, and the probability of drought and precipitation deficits in some regions.

Evidence from attributed changes in some climate and weather extremes for a global warming of about 0.5°C supports the assessment that an additional 0.5°C of warming compared to present is associated with further detectable changes in these extremes. Several regional changes in climate are assessed to occur with global warming up to 1.5°C compared to pre industrial levels, including warming of extreme temperatures in many regions, increases in frequency, intensity, and/or amount of heavy precipitation in several regions, and an increase in intensity or frequency of droughts in some regions.

Temperature extremes on land are projected to warm more than GMST: extreme hot days in mid latitudes warm by up to about 3°C at global warming of 1.5°C and about 4°C at 2°C, and extreme cold nights in high latitudes warm by up to about 4.5°C at 1.5°C and about 6°C at 2°C. The number of hot days is projected to increase in most land regions, with highest increases in the tropics.

Risks from droughts and precipitation deficits are projected to be higher at 2°C compared to 1.5°C of global warming in some regions. Risks from heavy precipitation events are projected to be higher at 2°C compared to 1.5°C of global warming in several northern hemisphere, high latitude and/or high-elevation regions, eastern Asia and eastern North America. Heavy precipitation associated with tropical cyclones is projected to be higher at 2°C compared to 1.5°C global warming. There is generally low confidence in projected changes in heavy precipitation at 2°C compared to 1.5°C in other regions. Heavy precipitation when aggregated at global scale is projected to be higher at 2°C than at 1.5°C of global warming. As a consequence of heavy precipitation, the fraction of the global land area affected by flood hazards is projected to be larger at 2°C compared to 1.5°C of global warming.

By 2100, global mean sea level rise is projected to be around 0.1 metre lower with global warming of 1.5°C compared to 2°C. Sea level will continue to rise well beyond 2100, and the magnitude and rate of this rise depend on future emission pathways. A slower rate of sea level rise enables greater opportunities for adaptation in the human and ecological systems of small islands, low lying coastal areas and deltas.

Model based projections of global mean sea level rise (relative to 1986-2005) suggest an indicative range of 0.26 to 0.77m by 2100 for 1.5°C of global warming, 0.1m (0.04-0.16m) less than for a global warming of 2°C. A reduction of 0.1m in global sea level rise implies that up to 10 million fewer people would be exposed to related risks, based on population in the year 2010 and assuming no adaptation.

Sea level rise will continue beyond 2100 even if global warming is limited to 1.5°C in the 21st century. Marine ice sheet instability in Antarctica and/or irreversible loss of the Greenland ice sheet could result in multi metre rise in sea level over hundreds to thousands of years. These instabilities could be triggered at around 1.5°C to 2°C of global warming.

Increasing warming amplifies the exposure of small islands, low-lying coastal areas and deltas to the risks associated with sea level rise for many human and ecological systems, including increased saltwater intrusion, flooding and damage to infrastructure. Risks associated with sea level rise are higher at 2°C compared to 1.5°C. The slower rate of sea level rise at global warming of 1.5°C reduces these risks, enabling greater opportunities for adaptation including managing and restoring natural coastal ecosystems and infrastructure reinforcement.

On land, impacts on biodiversity and ecosystems, including species loss and extinction, are projected to be lower at 1.5°C of global warming compared to 2°C. Limiting global warming to 1.5°C compared to 2°C is projected to lower the impacts on terrestrial, freshwater and coastal ecosystems and to retain more of their services to humans.

Of 105,000 species studied, 6% of insects, 8% of plants and 4% of vertebrates are projected to lose over half of their climatically determined geographic range for global warming of 1.5°C, compared with 18% of insects, 16% of plants and 8% of vertebrates for global warming of 2°C. Impacts associated with other biodiversity related risks such as forest fires and the spread of invasive species are lower at 1.5°C compared to 2°C of global warming.

Approximately 4% (interquartile range 2-7%) of the global terrestrial land area is projected to undergo a transformation of ecosystems from one type to another at 1°C of global warming, compared with 13% (interquartile range 8-20%) at 2°C. This indicates that the area at risk is projected to be approximately 50% lower at 1.5°C compared to 2°C.

High latitude tundra and boreal forests are particularly at risk of climate change-induced degradation and loss, with woody shrubs already encroaching into the tundra and this will proceed with further warming. Limiting global warming to 1.5°C rather than 2°C is projected to prevent the thawing over centuries of a permafrost area in the range of 1.5 to 2.5 million km2.

Limiting global warming to 1.5°C compared to 2°C is projected to reduce increases in ocean temperature as well as associated increases in ocean acidity and decreases in ocean oxygen levels. Consequently, limiting global warming to 1.5°C is projected to reduce risks to marine biodiversity, fisheries, and ecosystems, and their functions and services to humans, as illustrated by recent changes to Arctic sea ice and warm water coral reef ecosystems.

There is high confidence that the probability of a sea ice-free Arctic Ocean during summer is substantially lower at global warming of 1.5°C when compared to 2°C. With 1.5°C of global warming, one sea ice free Arctic summer is projected per century. This likelihood is increased to at least one per decade with 2°C global warming. Effects of a temperature overshoot are reversible for Arctic sea ice cover on decadal time scales.

Global warming of 1.5°C is projected to shift the ranges of many marine species to higher latitudes as well as increase the amount of damage to many ecosystems. It is also expected to drive the loss of coastal resources and reduce the productivity of fisheries and aquaculture (especially at low latitudes). The risks of climate induced impacts are projected to be higher at 2°C than those at global warming of 1.5°C. Coral reefs, for example, are projected to decline by a further 70-90% at 1.5°C with larger losses (>99%) at 2°C. The risk of irreversible loss of many marine and coastal ecosystems increases with global warming, especially at 2°C or more.

The level of ocean acidification due to increasing CO2 concentrations associated with global warming of 1.5°C is projected to amplify the adverse effects of warming, and even further at 2°C, impacting the growth, development, calcification, survival, and thus abundance of a broad range of species, for example, from algae to fish.

Impacts of climate change in the ocean are increasing risks to fisheries and aquaculture via impacts on the physiology, survivorship, habitat, reproduction, disease incidence, and risk of invasive species, but are projected to be less at 1.5°C of global warming than at 2°C. One global fishery model, for example, projected a decrease in global annual catch for marine fisheries of about 1.5 million tonnes for 1.5°C of global warming compared to a loss of more than 3 million tonnes for 2°C of global warming.

Climate-related risks to health, livelihoods, food security, water supply, human security, and economic growth are projected to increase with global warming of 1.5°C and increase further with 2°C.

Populations at disproportionately higher risk of adverse consequences with global warming of 1.5°C and beyond include disadvantaged and vulnerable populations, some indigenous peoples, and local communities dependent on agricultural or coastal livelihoods. Regions at disproportionately higher risk indude Arctic ecosystems, dryland regions, small island developing states, and Least Developed Countries. Poverty and disadvantage are expected to increase in some populations as global warming increases; limiting global warming to 1.5°C, compared with 2°C, could reduce the number of people both exposed to climate related risks and susceptible to poverty by up to several hundred million by 2050.

Any increase in global warming is projected to affect human health, with primarily negative consequences. Lower risks are projected at 1.5°C than at 2°C for heat related morbidity and mortality and for ozone related mortality if emissions needed for ozone formation remain high. Urban heat islands often amplify the impacts of heatwaves in cities. Risks from some vector-borne diseases, such as malaria and dengue fever, are projected to increase with warming from 1.5°C to 2°C, including potential shifts in their geographic range.

Limiting warming to 1.5°C compared with 2°C is projected to result in smaller net reductions in yields of maize, rice, wheat, and potentially other cereal crops, particularly in sub-Saharan Africa, Southeast Asia, and Central and South America, and in the CO2-dependent nutritional quality of rice and wheat. Reductions in projected food availability are larger at 2°C than at 1.5°C of global warming in the Sahel, southern Africa, the Mediterranean, central Europe, and the Amazon. Livestock are projected to be adversely affected with rising temperatures, depending on the extent of changes in feed quality, spread of diseases, and water resource availability.

Depending on future socio-economic conditions, limiting global warming to 1.5°C compared to 2°C may reduce the proportion of the world population exposed to a climate change-induced increase in water stress by up to 50%, although there is considerable variability between regions. Many small island developing states could experience lower water stress as a result of projected changes in aridity when global warming is limited to 1.5°C, as compared to 2°C.

Risks to global aggregated economic growth due to climate change impacts are projected to be lower at 1.5°C than at 2°C by the end of this century. This excludes the costs of mitigation, adaptation investments and the benefits of adaptation. Countries in the tropics and Southern Hemisphere subtropics are projected to experience the largest impacts on economic growth due to ciimate change should global warming increase fiom 1.5°C to 2°C.

Exposure to multiple and compound climate-related risks increases between 1.5°C and 2°C of global warming, with greater proportions of people both so exposed and susceptible to poverty in Africa and Asia. For global warming from 1.5°C to 2°C, risks across energy, food, and water sectors could overlap spatially and temporally, creating new and exacerbating current hazards, exposures, and vulnerabilities that could affect increasing numbers of people and regions.

There are multiple lines of evidence that since ARS the assessed levels of risk increased for four of the five Reasons for Concern (RFCs) for global warming to 2°C. The risk transitions by degrees of global warming are now: from high to very high risk between 1.5°C and 2°C for RFC1 (Unique and threatened systems; from moderate to high risk between 1°C and 1.5°C for RFC2 (Extreme weather events); from moderate to high risk between 1.5°C and 2°C for RFC3 (Distribution of impacts; from moderate to high risk between 1.5°C and 2.5°C for RFC4 (Global aggregate impacts); and from moderate to high risk between 1°C and 2.5°C for RFC5 (Large-scale singular events).

Most adaptation needs will be lower for global warming of 1.5°C compared to 2°C. There are a wide range of adaptation options that can reduce the risks of climate change. There are limits to adaptation and adaptive capacity for some human and natural systems at global warming of 1.5°C, with associated losses. The number and availability of adaptation options vary by sector.

A wide range of adaptation options are available to reduce the risks to natural and managed ecosystems (e.g., ecosystem based adaptation, ecosystem restoration and avoided degradation and deforestation, biodiversity management, sustainable aquaculture, and local knowledge and indigenous knowledge). the risks of sea level rise (e.g., coastal defence and hardening), and the risks to health, livelihoods, food, water, and economic growth, especially in rural landscapes (e.g., efficient itrigation, social safety nets, disaster risk management. risk spreading and sharing, and community based adaptation) and urban areas (e.g., green inftastructure, sustainable land use and planning, and sustainable water management).

Adaptation is expected to be more challenging for ecosystems, food and health systems at 2°C of global warming than for 1.5°C. Some vulnerable regions, including small islands and Least Developed Countries, are projected to experience high multiple interrelated climate risks even at global warming of 1.5°C.

Limits to adaptive capacity exist at 1.5°C of global warming, become more pronounced at higher levels of warming and vary by sector, with site specific implications for vulnerable regions, ecosystems and human health.

Figure SPM.2 Five integrative reasons for concern (RFCs) provide a framework for summarizing key impacts and risks across sectors and regions, and were introduced in the IPCC Third Assessment Report. RFCs illustrate the implications of global warming for people, economies and ecosystems. impacts and/or risks for each RFC are based on assessment of the new literature that has appeared. As in ARS, this literature was used to make expert judgments to assess the levels of global warming at which levels of impact and/or risk are undetectable, moderate, high or very high. The selection of impacts and risks to natural, managed and human systems in the lower panel is illustrative and is not intended to be fully comprehensive.

RFC1 Unique and threatened systems: ecological and human systems that have restricted geographic ranges constrained by climate-related conditions and have high endemism or other distinctive properties. Examples include coral reefs, the Arctic: and Its indigenous people, mountain glaciers and biodiversity hotspots.

RFC2 Extreme weather events: risks/impacts to human health, livelihoods, assets and ecosystems from extreme weather events such as heat waves, heavy rain, drought and associated wildfires, and coastal flooding.

RFC3 Distribution of impacts: risks/impacts that disproportionately affect particular groups due to uneven distribution of physical climate change hazards. exposure or vulnerability.

RFC4 Global aggregate impacts: global monetary damage, global-scale degradation and loss of ecosystems and biodiversity.

RFC5 Large-scale singular events: are relatively large, abrupt and somettmes irreversable changes in systems that are caused by global warming. Examples include disintegration of the Greenland and Antarctic Ice sheets.

Emission Pathways and System Transitions Consistent with 1.5°C Global Warming

In model pathways with no or limited overshoot of 1.5°C, global net anthropogenic CO2 emissions decline by about 45% from 2010 levels by 2030 (40-60% interquartile range), reaching net zero around 2050 (2045-2055 interquartile range). For limiting global warming to below 2°C CO2 emissions are projected to decline by about 25% by 2030 in most pathways (10-30% interquartile range) and reach net zero around 2070 (2065-2080 interquartile range). Non CO2 emissions in pathways that limit global warming to 1.5°C show deep reductions that are similar to those in pathways limiting warming to 2°C.

CO2 emissions reductions that limit global warming to 1.5°C with no or limited overshoot can involve different portfolios of mitigation measures. striking different balances between lowering energy and resource intensity, rate of decarbonisation, and the reliance on carbon dioxide removal. Different portfolios face different implementation challenges and potential synergies and trade offs with sustainable development.

Modelled pathways that limit global warming to 1.5°C with no or limited overshoot involve deep reductions in emissions of methane and black carbon (35% or more of both by 2050 relative to 2010). These pathways also reduce most of the cooling aerosols, which partially offsets mitigation effects for two to three decades. Non CO2 emissions can be reduced as a result of broad mitigation measures in the energy sector. In addition, targeted non-C02 mitigation measures can reduce nitrous oxide and methane from agriculture, methane from the waste sector, some sources of black carbon, and hydrofluorocarbons. High bioenergy demand can increase emissions of nitrous oxide in some 1.5°C pathways, highlighting the importance of appropriate management approaches. Improved air quality resulting from projected reductions in many non-CO2 emissions provide direct and immediate population health benefits in all 1.5°C model pathways.

1 GtCO2 = 1 Gigatonne of CO2

1 Gigatonne = 1 Billion tonnes = 1 Trillion kilograms = 1,000,000,000,000 kilograms = 1 million x 1 million kilograms

Limiting global warming requires limiting the total cumulative global anthropogenic emissions of C02 since the pre industrial period, that is, staying within a total carbon budget. By the end of 2017, anthropogenic C02 emissions since the pre industrial period are estimated to have reduced the total carbon budget for 1.5°C by approximately 2200 ± 320 GtCO2. The associated remaining budget is being depleted by current emissions of 42 ± 3 GtCO2 per year. The choice of the measure of global temperature affects the estimated remaining carbon budget. Using global mean surface air temperature, as in ARS, gives an estimate of the remaining carbon budget of 580 GtCO2, for a 50% probability of limiting warming to 1.5°C, and 420 GtCO2 for a 66% probability. Alternatively, using GMST gives estimates of 770 and 570 GtCO2 for 50% and 66% probabilities respectively.

Uncertainties in the size of these estimated remaining carbon budgets are substantial and depend on several factors. Uncertainties in the climate response to C02 and non-CO2 emissions contribute ±400 GtCO2, and the level of historic warming contributes ±250 GtCO2. Potential additional carbon release from future permafrost thawing and methane release from wetlands would reduce budgets by up to 100 GtCO2 over the course of this century and more thereafter. In addition, the level of non-C02 mitigation in the future could alter the remaining carbon budget by 250 GtCO2 in either direction.

Solar radiation modification (SRM) measures are not included in any of the available assessed pathways. Although some SRM measures may be theoretically effective in reducing an overshoot, they face large uncertainties and knowledge gaps, as well as substantial risks and institutional and social constraints to deployment related to governance, ethics, and impacts on sustainable development. They also do not mitigate ocean acidification.

Figure SPM.3a Global emissions pathway characteristics, The main panel shows global net anthropogenic C02 emissions in pathways limiting global warming to 1.5°C, with no or limited (less than 0.1°C) overshoot and pathways wih higher overshoot. The shaded area shows the full range for pathways analysed in this report. The panels on the right show non-CO2 emissions ranges for three compounds with large historical forcing and a substantial portion of emissions coming from sources distinct from those centraI to C02 mitigation. Shaded areas In these panels show the 5-95% (light shading) and interquartile (dark shading) ranges of pathways limiting global warmIng to 1.5°C with no limited overshoot.

Box and whiskers at the bottom of the figure show the timing of pathways reachlng global net zero CO2 emission on levels, and a comparkson with pathways limiting global warmlng to 2°C with at least 66% probability. Four Illustrative model pathways are highlighted in the main panel and are labelled P1, P2, P3 and P4, correspondlng to the LED, S1, S2, and S5 pathways assessed in Chapter 2. Descriptions and characteristics of these pathways are available In Figure SPM3b.

Characteristics of four illustrative model pathways

Different mitigation strategies can achieve the net emissions reductions that would be required to follow a pathway that limits global warming to 1.5°C with no or limited overshoot. All pathways use Carbon Dioxide Removal (CDR), but the amount varies across pathways, as do the relative contributions of Bioenergy with Carbon Capture and Storage (BECCS) and removals in the Agriculture, Forestry and Other Land Use (AFOLU) sector. This has implications for emissions and several other pathway characteristics.

Figure SPM.3b Characteristics of four illustrative model pathways in relation to global warming of 1.5°C introduced in Fgure SPM.3a. These pathways were selected to show a range of potennal mitigation approaches and vary widely in the projected energy and land use, as well as their assumptIons about future socio economlc developments. Including economic and population growth, equity and sustainability. A breakdown of the global net anthropogenic C02 emissions into the contributions in terms of C02 emissions from fossil fuel and industry; agriculture, forestry and other land use (AFOLU); and bioenergy with carbon capture and storage (BECCS) is shown. AFOLU estlmates reported here are not necessarily comparable with countries estimates. Further characteristics for each of these pathways are listed below each pathway, These pathways illustrate relative global differences in mitigation strategies, but do not represent central estimates, national strategies, and do not indicate requirements. For comparison, the rIghi most column shows the interquartile ranges across pathways with no or limited overshoot of 1.5°C. Pathways P1, P2, P3 and P4 correspond to the LED, S1, S2 and S5 pathways assessed In Chapter 2.

Pathways limiting global warming to 1.5°C with no or limited overshoot would require rapid and far reaching transitions in energy, land, urban and infrastructure, including transport and buildings, and industrial systems. These systems transitions are unprecedented in terms of scale, but not necessarily in terms of speed, and imply deep emissions reductions in all sectors, a wide portfolio of mitigation options and a significant upscaling of investments in those options.

Pathways that limit global warming to 1.5°C with no or limited overshoot show system changes that are more rapid and pronounced over the next two decades than in 2°C pathways. The rates of system changes associated with limiting global warming to 1.5°C with no or limited overshoot have occurred in the past within specific sectors, technologies and spatial contexts, but there is no documented historic precedent for their scale.

In energy systems, modelled global pathways (considered in the literature) limiting global warming to 1.5°C with no or limited overshoot (for more details see Figure SPM.3b) generally meet energy service demand with lower energy use, including through enhanced energy efficiency, and show faster electrification of energy end use compared to 2°C. In 1.5°C pathways with no or limited overshoot, low emission energy sources are projected to have a higher share, compared with 2°C pathways, particularly before 2050. In 1.5°C pathways with no or limited overshoot, renewables are projected to supply 70-85% (interquartile range) of electritity in 2050. In electricity generation, shares of nuclear and fossil fuels with carbon dioxide capture and storage (CCS) are modelled to increase in most 1.5“C pathways with no or limited overshoot.

In modelled 1.5°C pathways with limited or no overshoot, the use of CCS would allow the electricity generation share of gas to be approximately 8% (3-11% interquartile range) of global electricity in 2050, while the use of coal shows a steep reduction in all pathways and would be reduced to close to 0% (0-2% interquartile range) of electricity.

While acknowledging the challenges, and differences between the options and national circumstances, political, economic, social and technical feasibility of solar energy, wind energy and electricity storage technologies have substantially improved over the past few years. These improvements signal a potential system transition in electricity generation.

CO2 emissions from industry in pathways limiting global warming to 1.5°C with no or limited overshoot are projected to be about 65-90% (interquartile range) lower in 2050 relative to 2010, as compared to 50-80% for global warming of 2°C. Such reductions can be achieved through combinations of new and existing technologies and practices, including electrification, hydrogen, sustainable bio-based feedstocks. product substitution, and carbon capture utilization and storage (CCUS). These options are technically proven at various scales but their large scale deployment may be limited by economic, financial, human capacity and institutional constraints in specific contexts, and specific characteristics of large-scale industrial installations. In industry, emissions reductions by energy and process efficiency by themselves are insufficient for limiting warming to 1.5°C with no or limited overshoot.

The urban and infrastructure system transition consistent with limiting global warming to 1.5°C with no or limited overshoot would imply, for example, changes in land and urban planning practices, as well as deeper emissions reductions in transport and buildings compared to pathways that limit global warming below 2°C. Technical measures and practices enabling deep emissions reductions include various energy efficiency options.

In pathways limiting global warming to 1.5°C with no or limited overshoot, the electricity share of energy demand in buildings would be about 55-75% in 2050 compared to 50-70% in 2050 for 2°C global warming. In the transport sector, the share of low emission final energy would rise from less than 5% in 2020 to about 35-65% in 2050 compared to 25-45% for 2°C of global warming. Economic, institutional and socio cultural barriers may inhibit these urban and infrastructure system transitions, depending on national, regional and local circumstances, capabilities and the availability of capital.

Transitions in global and regional land use are found in all pathways limiting global warming to 1.5°C with no or limited overshoot, but their scale depends on the pursued mitigation portfolio. Model pathways that limit global warming to 1.5°C with no or limited overshoot project a 4 million km2 reduction to a 2.5 million km2 increase of non-pasture agricultural land for food and feed crops and a 0.5-11 million km2 reduction of pasture land, to be converted into a 0-6 million km2 increase of agricultural land for energy crops and a 2 million km2 reduction to 9.5 million km2 increase in forests by 2050 relative to 2010. Land-use transitions of similar magnitude can be observed in modelled 2°C pathways.

Such large transitions pose profound challenges for sustainable management of the various demands on land for human settlements, food, livestock feed, fibre, bioenergy, carbon storage, biodiversity and other ecosystem services.

Mitigation options limiting the demand for land include sustainable intensification of land-use practices, ecosystem restoration and changes towards less resource intensive diets. The implementation of land based mitigation options would require overcoming socio-economic, institutional, technological, financing and environmental barriers that differ across regions.

Additional annual average energy-related investments for the period 2016 to 2050 in pathways limiting warming to 1.5°C compared to pathways without new climate policies beyond those in place today are estimated to be around 830 billion USD2010 (range of 150 billion to 1700 billion USD2010 across six models). This compares to total annual average energy supply investments in 1.5°C pathways of 1460 to 3510 billion USD2010 and total annual average energy demand investments of 640 to 910 billion USD2010 for the period 2016 to 2050. Total energy-related investments increase by about 12% (range of 3% to 24%) in 1.5°C pathways relative to 2°C pathways. Annual investments in low-carbon energy technologies and energy efficiency are upscaled by roughly a factor of six (range of factor of 4 to 10) by 2050 compared to 2015.

Modelled pathways limiting global warming to 1.5°C with no or limited overshoot project a wide range of global average discounted marginal abatement costs over the 21st century. They are roughly 3-4 times higher than in pathways limiting global warming to below 2°C. The economic literature distinguishes marginal abatement costs from total mitigation costs in the economy. The literatute on total mitigation costs of 1.5°C mitigation pathways is limited and was not assessed in this Report. Knowledge gaps remain in the integrated assessment of the economy wide costs and benefits of mitigation in line with pathways limiting warming to 1.5°C.

All pathways that limit global warming to 1.5°C with limited or no overshoot project the use of carbon dioxide removal (CDR) on the order of 100-1000 GtCO2 over the 21st century. CDR would be used to compensate for residual emissions and, in most cases. achieve net negative emissions to return global warming to 1.5°C following a peak. CDR deployment of several hundreds of GtCO2 is subject to multiple feasibility and sustainability constraints. Significant near term emissions reductions and measures to lower energy and land demand can limit CDR deployment to a few hundred GtCO2 without reliance on bioenergy with carbon capture and storage (BECCS).

Existing and potential CDR measures include afforestation and reforestation, land restoration and soil carbon sequestration, BECCS, direct air carbon capture and storage (DACCS), enhanced weathering and ocean alkalinization. These differ widely in terms of maturity, potentials, costs, risks, co-benefits and trade offs. To date, only a few published pathways include CDR measures other than afforestation and BECCS.

In pathways limiting global warming to 1.5°C with limited or no overshoot, BECCS deployment is projected to range from 0-1, 0-8, and 0-16 GtCO2/yr in 2030, 2050, and 2100, respectively, while agriculture, forestry and land-use (AFOLU) related CDR measures are projected to remove 0-5, 1-11, and 1-5 GtCO2/yr in these years. The upper end of these deployment ranges by mid-century exceeds the BECCS potential of up to 5 GtCO2/yr and afforestation potential of up to 3.6 GtCO2/yr assessed based on recent literature. Some pathways avoid BECCS deployment completely through demand side measures and greater reliance on AFOLU-related CDR measures. The use of bioenergy can be as high or even higher when BECCS is excluded compared to when it is included due to its potential for replacing fossil fuels across sectors.

Pathways that overshoot 1.5°C of global warming rely on CDR exceeding residual CO2 emissions later in the century to return to below 1.5°C by 2100, with larger overshoots requiring greater amounts of CDR. Limitations on the speed, scale, and societal acceptability of CDR deployment hence determine the ability to return global warming to below 1.5°C following an overshoot. Carbon cycle and climate system understanding is still limited about the effectiveness of net negative emissions to reduce temperatures after they peak.

Most current and potential CDR measures could have significant impacts on land, energy, water or nutrients if deployed at large scale. Afforestation and bioenergy may compete with other land uses and may have significant impacts on agricultural and food systems, biodiversity, and other ecosystem functions and services. Effective governance is needed to limit such trade offs and ensure permanence of carbon removal in terrestrial, geological and ocean reservoirs. Feasibility and sustainability of CDR use could be enhanced by a portfolio of options deployed at substantial, but lesser scales, rather than a single option at very large scale.

Some AFOLU-related CDR measures such as restoration of natural ecosystems and soil carbon sequestration could provide co-benefits such as improved biodiversity, soil quality, and local food security. If deployed at large scale, they would require governance systems enabling sustainable land management to conserve and protect land carbon stocks and other ecosystem functions and services.

Strengthening the Global Response in the Context of Sustainable Development and Efforts to Eradicate Poverty

Estimates of the global emissions outcome of current nationally stated mitigation ambitions as submitted under the Paris Agreement would lead to global greenhouse gas emissions in 2030 of 52-58 GtCO2eq yr. Pathways reflecting these ambitions would not limit global warming to 1.5°C, even if supplemented by very challenging increases in the scale and ambition of emissions reductions after 2030. Avoiding overshoot and reliance on future large scale deployment of carbon dioxide removal (CDR) can only be achieved if global CO2 emissions start to decline well before 2030.

Pathways that limit global warming to 1.5°C with no or limited overshoot show clear emission reductions by 2030. All but one show a decline in global greenhouse gas emissions to below 35 GtCO2eq yr in 2030, and half of available pathways fall within the 25-30 GtCO2eq yr range (interquartile range), a 40-50% reduction from 2010 levels.

Pathways reflecting current nationally stated mitigation ambition until 2030 are broadly consistent with cost-effective pathways that result in a global warming of about 3°C by 2100, with warming continuing afterwards.

Overshoot trajectories result in higher impacts and associated challenges compared to pathways that limit global warming to 1.5°C with no or limited overshoot. Reversing warming after an overshoot of 0.2°C or larger during this century would require upscaling and deployment of CDR at rates and volumes that might not be achievable given considerable implementation challenge.

The lower the emissions in 2030, the lower the challenge in limiting global warming to 1.5°C after 2030 with no or limited overshoot. The challenges from delayed actions to reduce greenhouse gas emissions include the risk of cost escalation, lock-in in carbon-emitting infrastructure, stranded assets, and reduced flexibility in future response options in the medium to long term. These may increase uneven distributional impacts between countries at different stages of development.

The avoided climate change impacts on sustainable development, eradication of poverty and reducing inequalities would be greater if global warming were limited to 1.5°C rather than 2°C, if mitigation and adaptation synergies are maximized while trade offs are minimized.

Climate change impacts and responses are closely linked to sustainable development which balances social well-being, economic prosperity and environmental protection.The United Nations Sustainable Development Goals (SDGs), adopted in 2015, provide an established framework for assessing the links between global warming of 1.5°C or 2°C and development goals that include poverty eradication, reducing inequalities, and climate action.

The consideration of ethics and equity can help address the uneven distribution of adverse impacts associated with 1.5°C and higher levels of global warming, as well as those from mitigation and adaptation, particularly for poor and disadvantaged populations, in all societies.

Mitigation and adaptation consistent with limiting global warming to 1.5°C are underpinned by enabling conditions, assessed in this report across the geophysical, environmental, ecological, technological, economic, socio cultural and institutional dimensions of feasibility. Strengthened multilevel governance, institutional capacity, policy instruments, technological innovation and transfer and mobilization of finance, and changes in human behaviour and lifestyles are enabling conditions that enhance the feasibility of mitigation and adaptation options or 1.5°C-consistent systems transitions.

Adaptation options specific to national contexts, if carefully selected, together with enabling conditions, will have benefits for sustainable development and poverty reduction with global warming of 1.5°C, although trade-offs are possible.

Adaptation options that reduce the vulnerability of human and natural systems have many synergies with sustainable development, if well managed, such as ensuring food and water security, reducing disaster risks, improving health conditions, maintaining ecosystem services and reducing poverty and inequality. Increasing investment in physical and social infrastructure is a key enabling condition to enhance the resilience and the adaptive capacities of societies. These benefits can occur in most regions with adaptation to 1.5°C of global warming.

Adaptation to 1.5°C global warming can also result in trade-offs or maladaptations with adverse impacts for sustainable development. For example, if poorly designed or implemented adaptation projects in a range of sectors can increase greenhouse gas emissions and water use, increase gender and social inequality, undermine health conditions, and encroach on natural ecosystems. These trade-offs can be reduced by adaptations that include attention to poverty and sustainable development.

A mix of adaptation and mitigation options to limit global warming to 1.5°C, implemented in a participatory and integrated manner, can enable rapid, systemic transitions in urban and rural areas. These are most effective when aligned with economic and sustainable development, and when local and regional governments and decision makers are supported by national governments.

Adaptation options that also mitigate emissions can provide synergies and cost savings in most sectors and system transitions, such as when land management reduces emissions and disaster risk, or when low-carbon buildings are also designed for efficient cooling. Trade-offs between mitigation and adaptation, when limiting global warming to 1.5°C, such as when bioenergy crops, reforestation or afforestation encroach on land needed for agricultural adaptation, can undermine food security, livelihoods, ecosystem functions and services and other aspects of sustainable development.

Mitigation options consistent with 1.5°C pathways are associated with multiple synergies and trade offs across the Sustainable Development Goals (SDGs). While the total number of possible synergies exceeds the number of trade-offs, their net effect will depend on the pace and magnitude of changes, the composition of the mitigation portfolio and the management of the transition.

1.5°C pathways have robust synergies particularly for the SDGs 3 (health), 7 (clean energy). 11 (cities and communities), 12 (responsible consumption and production) and 14 (oceans). Some 1.5°C pathways show potential trade-offs with mitigation for SDGs 1 (poverty), 2 (hunger), 6 (water) and 7 (energy access), if not managed carefully.

1.5°C pathways that include low energy demand, low material consumption, and low GHG-intensive food consumption have the most pronounced synergies and the lowest number of trade-offs with respect to sustainable development and the SDGs. Such pathways would reduce dependence on CDR. In modelled pathways, sustainable development, eradicating poverty and reducing inequality can support limiting warming to 1.5°C.

Indicative linkages between mitigation options and sustainable development using SDGs

(The linkages do not show costs and benefits)

Mitigation options deployed in each sector can be associated with potential positive effects (synergies) or negative effects (trade-offs) with the Sustainable Development Goals (SDGs). The degree to which this potential is realized will depend on the selected portfolio of mitigation options, mitigation policy design, and local circumstances and context. Particularly in the energy demand sector, the potential for synergies is larger than for trade-offs. The bars group individually assessed options by level of confidence and take into account the relative strength of the assessed mitigation SDG connections.

Figure SPM4 Potential synergies and trad-Offs between the sectoral portfolio of climate change mitigation options and the Sustainable Development Goals (SDGs). The SDGs serve as an analytlcal framework for the assessment of the different sustainable development dimensions, WhIic extend beyond the time frame of the 2030 SDG targets. The assessment is based on literature on mitigation options that are considered relevant fot 1.5°C.

The assessed strength of the SDG interactions id based on the qualitative and quantitative assessment of individual mitigation uptions listed in Table 5.1. For each mitigation option, the strength of the SDG connection as well as the associated confidence of the under lying literature (shades of green and red) was assessed, The strength of positive connections (synergies) and negative connections (trade-offs) across all individual options within a sector (see Table 5.2) are aggregated into sectoral potentials for the whole mitigation portfolio. The white areas outside the bars, which indicate no interactlons, have low confidence due to the untertainty and limited number of studies exploring more direct effects. The strength of the connection consnders only the effect on mitigation and does not include benefits of avoided impacts. SDG 13 (climate action) is not listed because mitigation is being considered in terms of Interactions with SDGs and not vice versa. The bars denote the strength of the connection, and do not consider the strength of the impact on the SDGs. The energy demand sector comprises behavioural responses, fuel swiching and efficiency options in the transport industry and building sector as well as carbon capture options in the industry sector. Options assessed in the energy supply sector comprise biomass and non-biomass renewables, nuclear, carbon capture and storage (CCS) with bioenergy, and CCS with fossil fuels. Options in the land sector comprise agricultural and forest options, sustainable diets and reduced food waste, soil sequestration, livestock and manure management, reduced detorestation, afforestation and reforestation, and responstble sourcing. In addition to this figure, options in the ocean sector are discussed in the underlying report.

Informatton about the net impacts of mitigation on sustainable development in 1.5°C pathways is available only for a limited number of SDGs and mitigation options. Only a limited number of studies have assessed the benefits of avoided climate change impacts of 1.5°C pathways for the SDG, and the co-effects of adaptation for mitigation and the SDGs. The assessment of the indicative mitigation potentials In Figure SPM4 is a step further from ARS towards a more comprehenstve and integrated assessment in the future.

1.5°C and 2°C modelled pathways often rely on the deployment of large-scale land-related measures like afforestation and bioenergy supply, which, if poorly managed, can compete with food production and hence raise food security concerns. The impacts of carbon dioxide removal (CDR) options on SDGs depend on the type of options and the scale of deployment. If poorly implemented, CDR options such as BECCS and AFOLU options would lead to trade-offs. Context-relevant design and implementation requires considering people’s needs, biodiversity, and other sustainable development dimensions.

Mitigation consistent with 1.5°C pathways creates risks for sustainable development in regions with high dependency on fossil fuels for revenue and employment generation. Policies that promote diversification of the economy and the energy sector can address the associated challenges.

Redistributive policies across sectors and populations that shield the poor and vulnerable can resolve trade-offs for a range of SDGs, particularly hunger, poverty and energy access. Investment needs for such complementary policies are only a small fraction of the overall mitigation investments in 1.5°C pathways.

Limiting the risks from global warming of 1.5°C in the context of sustainable development and poverty eradication implies system transitions that can be enabled by an increase of adaptation and mitigation investments, policy instruments, the acceleration of technological innovation and behaviour changes.

Directing finance towards investment in infrastructure for mitigation and adaptation could provide additional resources. This could involve the mobilization of private funds by institutional investors, asset managers and development or investment banks, as well as the provision of public funds. Government policies that lower the risk of low-emission and adaptation investments can facilitate the mobilization of private funds and enhance the effectiveness of other public policies. Studies indicate a number of challenges, including access to finance and mobilization of funds.

Adaptation finance consistent with global warming of 1.5°C is difficult to quantify and compare with 2°C. Knowledge gaps include insufficient data to calculate specific climate resilience-enhancing investments from the provision of currently underinvested basic infrastructure. Estimates of the costs of adaptation might be lower at global warming of 1.5°C than for 2°C. Adaptation needs have typically been supported by public sector sources such as national and subnational government budgets, and in developing countries together with support from development assistance, multilateral development banks, and United Nations Framework Convention on Climate Change channels.

More recently there is a growing understanding of the scale and increase in non-govemmental organizations and private funding in some regions. Barriers include the scale of adaptation financing, limited capacity and access to adaptation finance.

Global model pathways limiting global warming to 1.5°C are projected to involve the annual average investment needs in the energy system of around 2.4 trillion USD2010 between 2016 and 2035, representing about 2.5% of the world GDP.

Policy tools can help mobilize incremental resources, including through shifting global investments and savings and through market and non-market based instruments as well as accompanying measures to secure the equity of the transition. Acknowledging the challenges related with implementation, including those of energy costs, depreciation of assets and impacts on international competition, and milizing the opportunities to maximize co-benefits.

The systems transitions consistent with adapting to and limiting global warming to 1.5°C include the widespread adoption of new and possibly disruptive technologies and practices and enhanced climate-driven innovation. These imply enhanced technological innovation capabilities, including in industry and finance. Both national innovation policies and international cooperation can contribute to the development, commercialization and widespread adoption of mitigation and adaptation technologies. Innovation policies may be more effective when they combine public support for research and development with policy mixes that provide incentives for technology diffusion.

Education, information, and community approaches, including those that are informed by indigenous knowledge and local knowledge, can accelerate the wide scale behaviour changes consistent with adapting to and limiting global warming to 1.5°C. These approaches are more effective when combined with other policies and tailored to the motivations, capabilities and resources of specific actors and contexts. Public acceptability can enable or inhibit the implementation of policies and measures to limit global warming to 1.5°C and to adapt to the consequences. Public acceptability depends on the individual’s evaluation of expected policy consequences, the perceived fairness of the distribution of these consequences. and perceived fairness of decision procedures.

Sustainable development supports, and often enables, the fundamental societal and systems transitions and transformations that help limit global warming to 1.5°C. Such changes facilitate the pursuit of climate resilient development pathways that achieve ambitious mitigation and adaptation in conjunction with poverty eradication and efforts to reduce inequalities.

Social justice and equity are core aspects of climate-resilient development pathways that aim to limit global warming to 1.5°C as they address challenges and inevitable trade offs, widen opportunities, and ensure that options, visions, and values are deliberated, between and within countries and communities, without making the poor and disadvantaged worse off.

The potential for climate-resilient development pathways differs between and within regions and nations, due to different development contexts and systemic vulnerabilities. Efforts along such pathways to date have been limited and enhanced efforts would involve strengthened and timely action from all countries and non-state actors.

Pathways that are consistent with sustainable development show fewer mitigation and adaptation challenges and are associated with lower mitigation costs. The large majority of modelling studies could not construct pathways characterized by lack of international cooperation, inequality and poverty that were able to limit global warming to 1.5°C.

Strengthening the capacities for climate action of national and sub national authorities, civil society, the private sector, indigenous peoples and local communities can support the implementation of ambitious actions implied by limiting global warming to 1.5°C. International cooperation can provide an enabling environment for this to be achieved in all countries and for all people, in the context of sustainable development. International cooperation is a critical enabler for developing countries and vulnerable regions.

Partnerships involving non-state public and private actors, institutional investors, the banking system, civil society and scientific institutions would facilitate actions and responses consistent with limiting global warming to 1.5°C.

Cooperation on strengthened accountable multilevel governance that includes non-state actors such as industry, civil society and scientific institutions, coordinated sectoral and cross-sectoral policies at various governance levels, gender sensitive policies, finance including innovative financing. and cooperation on technology development and transfer can ensure participation, transparency, capacity building and learning among different players.

International cooperation is a critical enabler for developing countries and vulnerable regions to strengthen their action for the implementation of 1.5°C consistent climate responses, including through enhancing access to finance and technology and enhancing domestic capacities, taking into account national and local circumstances and needs.

Collective efforts at all levels, in ways that reflect different circumstances and capabilities, in the pursuit of limiting global warming to 1.5°C, taking into account equity as well as effectiveness, can facilitate strengthening the global response to climate change, achieving sustainable development and eradicating poverty.

Summary for Policymakers (pdf)

Full Report

THE EARTH IS IN A DEATH SPIRAL. It will take radical action to save us – George Monbiot.

“What is it that you are asking me as a 20-year-old to face and to accept about my future and my life? … This is an emergency. We are facing extinction. When you ask questions like that, what is it you want me to feel?”

Climate breakdown could be rapid and unpredictable. We can no longer tinker around the edges and hope minor changes will avert collapse.

Softer aims might be politically realistic, but they are physically unrealistic. Only shifts commensurate with the scale of our existential crises have any prospect of averting them. Hopeless realism, tinkering at the edges of the problem, got us into this mess. It will not get us out.

Public figures talk and act as if environmental change will be linear and gradual. But the Earth’s systems are highly complex, and complex systems do not respond to pressure in linear ways. When these systems interact (because the world’s atmosphere, oceans, land surface and lifeforms do not sit placidly within the boxes that make study more convenient), their reactions to change become highly unpredictable. Small perturbations can ramify wildly. Tipping points are likely to remain invisible until we have passed them. We could see changes of state so abrupt and profound that no continuity can be safely assumed.

Only one of the many life support systems on which we depend – soils, aquifers, rainfall, ice, the pattern of winds and currents, pollinators, biological abundance and diversity, need fail for everything to slide.

Because we cannot save ourselves without contesting oligarchic control, the fight for democracy and justice and the fight against environmental breakdown are one and the same. Do not allow those who have caused this crisis to define the limits of political action. Do not allow those whose magical thinking got us into this mess to tell us what can and cannot be done.

. . . The Guardian

Global warming will drive up suicide rates, study warns – Sharon Kirkey * How Climate Change Affects Mental Health – Katherine Schreiber * Mental Health and our Changing Climate, A Primer – APA.

The health, economic, political, and environmental implications of climate change affect all of us. The tolls on our mental health are far reaching. They induce stress, depression, and anxiety; strain social and community relationships; and have been linked to increases in aggression, violence, and crime.

Heat profoundly affects the human mind. The more neurotransmitters needed to cool the body, the less available to suppress emotions like aggression, impatience or violence. Heat increases circulating levels of the stress hormone, cortisol. Psychiatric hospital visits increase during hotter weather.

Virtually everywhere around the world we’re facing warmer temperatures, and there is a lot of evidence of direct effects of warming on mental health.

Although the psychological impacts of climate change may not be obvious, they are no less serious because they can lead to disorders, such as depression, antisocial behavior, and suicide. Therefore, these disorders must be considered impacts of climate change as are disease, hunger, and other physical health consequences.

Of the 36% of Americans who are personally concerned a great deal about climate issues, 72% are Democrats, and 27% are Republicans (PEW Research).

Sharon Kirkey

It was Raymond Chandler who wrote of nights with a hot wind blowing into Los Angeles, a wind that makes “your nerves jump.”

“On nights like that every booze party ends in a fight,” he wrote. “Meek little wives feel the edge of the carving knife and study their husbands’ necks. Anything can happen.”

Now there’s research that says climate change may damage our mental health, just like Chandler’s hot wind from the Santa Ana Mountains.

Last week, a team of 28 specialists convened by the Lancet medical journal listed climate change among the greatest threats to mental health globally.

Ferocious storms and more frequent weather extremes will affect the human psyche in costly ways, some scientists predict, from more depression and anxiety to increased suicide rates.

One working theory is that some of the same neurotransmitters used by the brain to regulate the body’s temperature are also used to control emotions. The more neurotransmitters needed to cool the body, the less available to suppress emotions like aggression, impatience or violence.

. . . National Post

How Climate Change Affects Mental Health.

A new report shows global warming affects our psyches just as much as our earth.

Katherine Schreiber

When we talk about climate change, we tend to think about its effects on our environment, melting polar ice caps, extreme swings in weather, more frequent droughts, flooding, and higher incidences of natural disasters. But what about the effect on our moods, thoughts, and feelings? A new report written by the American Psychological Association, Climate for Health, and ecoAmerica argues that our mental wellbeing is just as vulnerable to global warming as is our earth.

. . . Psychology Today

MENTAL HEALTH AND OUR CHANGING CLIMATE:

IMPACTS IMPLICATIONS, AND GUIDANCE

WHY WE OFFER THIS REPORT

When you think about climate change, mental health might not be the first thing that comes to mind. Americans are beginning to grow familiar with climate change and its health impacts: worsening asthma and allergies; heat-related stress: foodborne, waterborne, and vector-borne diseases; illness and injury related to storms; and floods and droughts. However, the connections with mental health are not often part of the discussion.

It is time to expand information and action on climate and health, including mental health. The health, economic, political, and environmental implications of climate change affect all of us. The tolls on our mental health are far reaching. They induce stress, depression, and anxiety; strain social and community relationships; and have been linked to increases in aggression, violence, and crime. Children and communities with few resources to deal with the impacts of climate change are those most impacted.

To compound the issue, the psychological responses to climate change, such as conflict avoidance, fatalism, fear, helplessness, and resignation are growing. These responses are keeping us, and our nation, from properly addressing the core causes of and solutions for our changing climate, and from building and supporting psychological resiliency.

To help increase awareness of these challenges and to address them, the American Psychological Association and ecoAmerica sponsored this report, Mental Health and Our Changing Climate: Impacts, Implications, and Guidance. This is an updated and expanded version of our 2014 report, Beyond Storms & Droughts: The Psychological Impacts of Climate Change, which explored how climate change can impact mental health and provided guidance to engage the public. This updated report is intended to further inform and empower health and medical professionals, community and elected leaders, and the public. Our websites offer webinars and other resources to supplement this report.

On behalf of the authors, the many professionals who contributed directly and indirectly to this work, and all those involved in expanding awareness of and action on climate and mental health, thank you for taking the time to review and share this important resource.

We invite your feedback, and as the field continues to grow, we’ll continue to update this work.

EXECUTIVE SUMMARY

Thus far, most research and communications on the impacts of climate change have emphasized the physical health effects, while mental health has been secondary. Building upon Beyond Storms and Droughts: The Psychological Impacts of Climate Change, the goal of this updated report is to increase awareness of the psychological impacts of climate change on human mental health and well-being. The report provides climate communicators, planners, policymakers, public health professionals, and other leaders the tools and tips needed to respond to these impacts and bolster public engagement on climate solutions.

The impacts of climate change on people’s physical, mental, and community health arise directly and indirectly. Some human health effects stem directly from natural disasters exacerbated by climate change, like floods, storms, wildfires, and heatwaves. Other effects surface more gradually from changing temperatures and rising sea levels that cause forced migration. Weakened infrastructure and less secure food systems are examples of indirect climate impacts on society‘s physical and mental health.

Some communities and populations are more vulnerable to the health-related impacts of climate change. Factors that may increase sensitivity to the mental health impacts include geographic location. presence of pre-existing disabilities or chronic illnesses, and socioeconomic and demographic inequalities, such as education level, income, and age.

In particular, stress from climate impacts can cause children to experience changes in behavior, development, memory, executive function, decision-making, and scholastic achievement.

The connection between changes in the climate and impacts on a person can be difficult to grasp. Although people’s understanding and knowledge of climate change can increase by experiencing the effects directly, perception, politics, and uncertainty can complicate this link. Psychological factors (like psychological distance), a political divide, uncertainty, helplessness, and denial influence the way people comprehend information and form their beliefs on climate change. Research on the impacts of climate change on human well-being is particularly important given the relationship among understanding, experiencing, and comprehending climate change. People’s willingness to support and engage in climate solutions is likely to increase if they can relate them to local experiences or if they see the relevance to their own health and well-being. Additionally, individuals who have higher perceived environmental self-efficacy, or the sense of being able to positively contribute, are more motivated to act on climate solutions.

Climate solutions are available now, are widespread, and support psychological health. Increasing adoption of active commuting, public transportation, green spaces, and clean energy are all solutions that people can choose to support and integrate into their daily lives. These climate solutions, among others, can help to curb the stress, anxiety, and other mental illnesses incurred from the decline of economies, infrastructure, and social identity that comes from damage to the climate.

Major acute mental health impacts include increases in trauma and shock, posttraumatic stress disorder (PTSD), compounded stress, anxiety, substance abuse, and depression. Climate change induced extreme weather, changing weather patterns, damaged food and water resources, and polluted air impact human mental health. Increased levels of stress and distress from these factors can also put strains on social relationships and even have impacts on physical health, such as memory loss, sleep disorders, immune suppression, and changes in digestion.

Major chronic mental health impacts include higher rates of aggression and violence, more mental health emergencies, an increased sense of helplessness, hopelessness, or fatalism, and intense feelings of loss. These feelings of loss may be due to profound changes in a personally important place (such as one’s home) and/or a sense that one has lost control over events in one’s life due to disturbances from climate change. Additionally, a sense of loss regarding one’s personal or occupational identity can arise when treasured objects are destroyed by a disaster or place-based occupations are disrupted by climate change.

Personal relationships and the ways in which people interact in communities and with each other are affected by a changing climate. Compounded stress from a changing environment, ecomigration, and/or ecoanxiety can affect community mental well-being through the loss of social identity and cohesion, hostility, violence, and interpersonal and intergroup aggression.

Psychological well-being includes positive emotions, a sense of meaning and purpose, and strong social connections. Although the psychological impacts of climate change may not be obvious, they are no less serious because they can lead to disorders, such as depression, antisocial behavior, and suicide. Therefore, these disorders must be considered impacts of climate change as are disease, hunger, and other physical health consequences.

Building resilience is essential to address the physical and mental health impacts of climate change. Many local governments within the United States and in other countries have created plans to protect and enhance infrastructure, but these plans tend to overlook the support needed to ensure thriving psychological well-being. There is an opportunity to include the resilience capacity of individuals and communities in the development of preparedness plans.

OUR CHANGING CLIMATE: A PRIMER

Our climate is changing at an accelerated rate and continues to have profound impacts on human health. This change jeopardizes not only physical health but also mental health.

ACCELERATION

From wildfires and drought in California to severe flooding in Maryland to Alaskan communities threatened by rising seas, we are clearly living through some of the most severe weather events in US. history as a result of damage to our climate. Thes impacts on our environment will, in turn, affect human health and community well-being.

CHANGES WORLDWIDE

Climate change is creating visible impacts worldwide, including many here in America. As seen in the tripling of heat waves between 2011 and 2012, weather patterns introduce lasting impacts, such as food insecurity. Similarly, rising sea-surface temperatures have been connected to increasing rates of disease for marine life and humans. Sea levels are estimated to increase anywhere from 8 inches to 6.6 feet due to warmer temperatures by 2100, putting 8 million Americans living in coastal areas at risk for flooding. In terms of our economy, Hurricane Sandy cost the United States around $68 billion in total. Droughts caused by increases in temperature and changing weather patterns cost California $2.7 billion in 2015 and Texas $7.62 billion in 2011. As these climate disturbances become more dramatic and persistent, we must prepare for these climate conditions.

COMMUNITIES ARE IMPACTED

Our communities’ health, infrastructure, and economy are directly connected to our climate. As temperatures increase, we experience higher levels of pollution, allergens, and diseases. Severe weather events threaten our businesses and vulnerable communities. Pollution and drought undermine our food and water supplies, and the latter increases the prevalence of wildfires that can destroy homes and communities. Although all Americans are affected, certain populations of concern will feel the impacts more severely. Together, communities can build resilience to a changing climate.

HEALTH IS IMPACTED

As severe weather events, poorer air quality, degraded food and water systems, and physical illnesses increase, the direct and indirect impacts on health must be understood. The next section highlights the physical health impacts of climate change, and the following sections delve deeper into the mental health impacts, and what can be done to protect human well-being.

THE CLIMATE AND HEALTH IMPACTS ON HUMANS

Health is more than the absence of disease. Health includes mental health, as well as physical well-being, and communities that fail to provide basic services and social support challenge both. As we think about the impacts of climate change on our communities, we need to recognize not only the direct effects but also the indirect consequences for human health based on damage to the physical and social community infrastructure. Regardless of how these impacts surface, whether they occur within a matter of hours or over several decades, the outcomes of climate change are interconnected to all facets of our health.

ACUTE IMPACTS:

DlSASTER-RELATED EFFECTS

Recent increases in natural disasters illustrate the relationship between the acceleration of climate change and severe weather.

Areas that endure a natural disaster face a number of risks and difficulties. Direct physical impacts range from brute physical trauma to more pernicious effects, like increased incidence of infectious disease, asthma, heart disease, and lung problems. These physical health impacts interact with mental health impacts.

Major and minor acute physical injury

Natural disasters lead to increased rates of death and injury. The most common causes of mortality during floods are drowning and acute physical trauma. This past year alone, deaths from flash floods have more than doubled the 10-year average. Many people sustain non-fatal injuries, such as cuts and broken bones.

Infrastructure, food, and water

The direct effect of a natural disaster is often exacerbated by a cascade of indirect consequences that follow. Natural disasters can lead to technological disasters (such as power outages), breakdowns in the water, sewer, and other infrastructure, or urban fires. For instance, the risk of carbon monoxide poisoning related to power outages increases as a result of climate change-induced disasters. Disruptions to medical infrastructure, including the provision of medical supplies, can transform minor issues into major and even fatal problems. In addition, disruptions in other types of services (e.g., cell phone communication, transportation, or waste management) add stress and difficulty during the aftermath of a disaster. These disruptions may impact people’s physical health by making it more difficult to access health care or by potentially increasing exposure to pests or hazardous substances (e.g., when there is no garbage pick-up. Loss of income while businesses are closed due to natural disasters can be a major threat to food security, especially for non-professionals or small business owners.

After effects

Additional health threats follow in the wake of a disaster. Floodwater has been shown to introduce toxic materials, water-borne diseases (e.g., respiratory illnesses, skin infections, and neurologic and gastrointestinal illness where there are poor hygiene resources), and vector-borne illnesses (e.g., West Nile). Other after effects of flooding include heart attack, heat stroke, dehydration, and stroke, particularly when the affected areas lack the necessary medical supplies. In addition, post-flood mold due to fungal growth inside houses can worsen allergy or asthma symptoms.

MORE GRADUAL HEALTH EFFECTS

Ongoing effects of climate change include rising sea levels, increases in temperature, and changes in precipitation that will affect agricultural conditions. The impacts on human health are less dramatic in the short term but in the long run can affect more people and have a fundamental impact on society.

Severe and changing weather

Periods of higher-than-normal heat result in higher rates of heat exhaustion, heat cramps, heat stroke, hospital admission for heart-related illnesses, and death.

It’s estimated that the average American citizen will experience between 4 and 8 times as many days above 95 degrees Fahrenheit each year as he or she does now by the end of the century. This increase will likely push Arizona’s above-95-degree days from 116 today to as many as 205 by 2099. In contrast, extreme winter storms can expose people to hypothermia and frostbite. Altered growing seasons and ocean temperatures change the timing and occurrence of diarrhea, fever, and abdominal cramps from pathogen transmissions in raw food. Additionally, changing weather patterns influence the expansion of the migration patterns of animals and insects. This expansion has already begun to result in the spread of vector-borne illness, such as Lyme disease, malaria, dengue fever, plague, and Zika virus to new U.S. geographic areas. For example, vector-borne illnesses carried by mosquitoes can capitalize on receding floodwater for mosquito breeding.

Respiratory issues and allergens

People exposed to ozone air pollution, which is emitted mostly by cars and industrial facilities and is intensified by warmer temperatures, are more likely to visit the hospital for respiratory issues, suffer from asthma, and die prematurely of strokes or heart attacks. Hotter and drier summers increase the frequency and intensity of large wildfires that contribute to smoke inhalation. Pollution contributes to higher levels of pollen and translates into longer and more prevalent allergy seasons.

Fetal and child development

CIimate-driven physical stress on mothers can cause adverse birth outcomes, such as preterm birth and low birth weight. Scientific research shows that children and developing fetuses are at particular risk from air pollution, heat, malnutrition, infectious diseases, allergies, and mental illnesses, which have detrimental impacts on development.

Water and food supply

Nutrition and food safety can be affected because climate change can lower crop yields, reduce the nutritional quality of food, interrupt distribution chains, and reduce access to food because families lose income. For example, higher C02 concentrations lower the levels of protein and essential minerals of widely consumed crops such as wheat, rice, and potatoes. Barriers to food transport, such as damage to infrastructure and displacement of employees, affect food markets by increasing food costs. Droughts, floods, and changes in the availability of fertile land lead to hunger and malnutrition, though these changes are less likely in wealthy countries, such as the United States. Nevertheless, there will be an increased likelihood of a global food market crisis as climate change accelerates. A two-degree Celsius increase in temperature places 100-400 million people at risk of hunger, according to the World Bank.

General fitness

Increased average temperatures and decreased air quality also lead to changes in the type of activities that people engage in, particularly outdoor activities and recreation. These changes, in turn, may be associated with increased rates of obesity and cardiovascular disease. Although people may compensate by exercising in indoor environments, reduced access to the restorative potential of outdoor environments may indirectly increase stress and bypass the long-term emotional benefits of taking physical activity outdoors.

LINKING PHYSICAL IMPACTS, MENTAL HEALTH, AND COMMUNITY WELL-BEING

MENTAL HEALTH

The ability to process information and make decisions without being disabled by extreme emotional responses is threatened by climate change. Some emotional response is normal, and even negative emotions are a necessary part of a fulfilling life. In the extreme case, however, they can interfere with our ablllty to think rationally, plan our behavior, and consider alternative actions. An extreme weather event can be a source of trauma, and the experience can cause disabling emotions. More subtle and indirect effects of climate change can add stress to people’s lives in varying degrees. Whether experienced indirectly or directly, stressors to our climate translate into impaired mental health that can result in depression and anxiety. Although everyone is able to cope with a certain amount of stress, the accumulated effects of compound stress can tip a person from mentally healthy to mentally ill. Even uncertalnty can be a source of stress and a risk factor for psychological distress. People can be negatively affected by hearing about the negative experiences of others, and by fears, founded or unfounded, about their own potential vulnerability.

PHYSICAL HEALTH AND MENTAL HEALTH

Compromised physical health can be a source of stress that threatens psychological well being. Conversely mental health problems can also threaten physical health, for example, by changing patterns of sleep, eating, or exercise and by reducung immune system function.

COMMUNITY HEALTH

Although resndents‘ mental and physical health affect communlties, the impacts of climate on community health can have a particularly strong effect on community fabric and interpersonal relationships. Altered environmental condtions due to climate change can shift the opportunities people have for social interaction, the ways in which they relate to each other. and their connectlons to the natural world.

COMPREHENDING CLIMATE CHANGE

Witnessing the visible impacts of climate change may help people overcome barriers to grasping the problem; however, comprehension has many facets.

PERCEPTION IS DIFFICULT

Although most people are generally aware that climate change is occurring, it continues to seem distant: something that will happen to others, in another place, at some unspecified future date. Psychologists refer to this idea as psychological distance. Terms such as “climate change” and “global warming” draw attention to the global scale rather than the personal impacts. Additionally, the signal of climate change is obscured by the noise of daily and seasonal weather variation. All this makes the issue easier for people to push aside, particularly when faced with other pressing life issues. When people learn about and experience local climate impacts, their understanding increases. Local effects of climate change are often more personally relevant than the general phenomenon of a warming climate, and particularly when knowledge of direct effects is combined with news stories of the imminent risks of climate change. Perceived experience of impacts is associated with increased concern and awareness about climate change, direct experience also increases people’s understanding of climate change. However, direct experience does not necessarily lead to behavior change. For example, experiencing water shortages may increase behavior changes in water use but not encourage other sustainable behavior. Similarly, research suggests experiencing temperature change has no impact on water use behavior.

A PARTISAN ISSUE

Politically polarized in the United States, climate change is perceived as an issue that belongs with the political left, which can suppress belief and concern and discussions about solutions. For example, of the 36% of Americans who are personally concerned a great deal about climate issues, 72% are Democrats, and 27% are Republicans. Political orientation can make open conversations about climate impacts and solutions difficult, and make those who are concerned about climate change feel isolated or paranoid in some circles.

Concerns about health impacts provide common ground for discussion with both ends of the political spectrum. Describing the health-related impacts of climate change and the relevant benefits of taking action to address the impacts can inspire hope among those who dismiss climate change. For instance, conservatives showed decreased support for climate action when the negative health effects were described as affecting people in a faraway country as opposed to people who live in the United States. Listing several health impacts is overwhelming, causing fatalism and diminished engagement.

UNCERTAINTY AND DENIAL

People feel uncertain about the threat of climate change and how to minimize the damage. The media have been criticized for promoting an inaccurate perception of climate change: for example, that there is more scientific controversy about climate change than actually exists. In some cases, information that increases perceptions of the reality of climate change may feel so frightening that it leads to denial and thus a reduction in concern and support for action. In addition, communicating scientific information is not easy; this complexity itself may be a problem. One study showed that people who received more complex information on environmental problems 1) felt more helpless and more inclined to leave the problem to the government; and 2) those who felt ignorant about the topic were more likely to want to avoid hearing about more negative information.

Worldviews and ideologies act as filters to help increase or decrease concern about climate change and motivate action toward solutions. People do not perceive the world neutraly. Instead, through directionally motivated cognition, individuals strive to maintain a world consistent with the ideology and values of their social groups. Because of this, individuals whose worldviews conflict with climate change realities actually may not perceive certain climate effects. Myers, Maibach, Roser-Renouf, Akerlof, and Leiserowitz (2012) found that individuals who were 1) either very concerned about or skeptical of climate change tended to report personal experience with climate change (or lack thereof) based on their pre-existing beliefs about its existence; and 2) individuals less engaged with the issue of climate change changed their beliefs about the existence of climate change based on perceived personal experience with its impacts. Ideologies of climate change and action may also contribute to widespread psychological denial. The distress of climate change can manifest in negative reactions to climate activism. These reactions are reflected in outlets such as social media, and researchers believe this behavior shifts others to denial.

CLIMATE SOLUTIONS BENEFIT MENTAL HEALTH

Physical commuting enhances a sense of well-being. Choosing to bike and/or walk (assuming it is safe and practical to do so) is one individual step that can help reduce the use of climate change-driving fossil fuels. Physical commuting also directly impacts depression, anxiety, PTSD, and other mental illnesses. People who bike and walk to work, school, appointments, and other activities not only reduce emissions and improve their physical health but also experience lower stress levels than car commuters. For instance, individuals who utilized the Washington DC. bikeshare program reported reduced stress levels and weight loss. Similarly, adolescents who actively commute to school show not only lower levels of perceived stress but also increased cardiovascular fitness, improved cognitive performance, and higher academic achievement.

Public transportation invigorates community mental health. Moving people from individual cars to public transit also results in lower greenhouse gas emissions. In addition, several studies have shown that using public transportation leads to an increase in community cohesion, recreational activities, neighborhood walkability, and reduced symptoms of depression and stress associated with less driving and more exercise. Meanwhile, traffic driving worsens air quality and contributes to reduced productivity and increased healthcare costs. Sound transportation systems and urban planning should be expanded as they lead to beneficial mental health and climate outcomes. Green spaces diminish stress. Parks and green corridors have been connected to improved air quality and can increase mental well-being. For example, trees sequester carbon, and green spaces absorb less heat than paved surfaces and buildings. More time spent interacting with nature has been shown to significantly lower stress levels and reduce stress-related illness. Interestingly, this evidence is supported across socioeconomic status, age, and gender. Likewise, individuals who move to areas with access to more green space showed sustained mental health improvements, while individuals who moved to areas with less access to green space experienced substantial negative mental health impacts. However, although a person’s physical and mental health is determined to a large degree by the neighborhood in which he or she lives, relocating to a greener neighborhood isn’t always an option. As planners and policymakers make decisions that will reshape the landscapes of our cities and communities, it is important to recognize the significance and role green areas have in improving air quality, reducing stress, and ensuring a healthy living environment for everyone.

Clean energy reduces health burdens. Wind, solar, hydro, and other clean energy as well as energy efficiency are not only climate-friendly; they also reduce particulates and pollution in the air. Studies on air quality and children’s lung development have shown that as air pollution is reduced, children display significant lung function improvements. Further research revealed that children exposed to higher levels of urban pollution are more likely to develop attention problems and symptoms of anxiety and depression, as well as lower academic performance and brain function. Clean energy provides an opportunity to protect populations of concern, such as children, who experience these impacts more severely.

Although the co-benefits are clear, more comprehensive research on the positive mental health outcomes of climate solutions is needed to bolster support. Research can further promote dynamic solutions as opportunities to improve our health. It is important to increase awareness of the daily choices we make, from how to get to work to the sources of energy to, the more climate-friendly behaviors become mainstreamed, the more they help populations of concern: children, elderly, sick, low income, etc. Fortunately, tangible and effective climate solutions are available today to implement and build upon.

MENTAL HEALTH IMPACTS

The mental health effects of Climate change are gaining public attention. A 2071 government report (US. Global Change Research Program) reviewed a large body of research to summarize the current state of knowledge. This report builds on that knowledge, and considers the direct and indirect effects of Climate change on mental health.

We start by describing the mental health effects on individuals, both short and long term, acute and chronic, the stressors that accumulate in the aftermath of a disaster, and the impacts that natural disasters have on social relationships, with consequences for health and well-being. We move on to discussing the individual-level impacts of more gradual changes in climate, including impacts on aggression and violence, identity, and the long-term emotional impacts of Climate change. Next, we discuss the impacts of climate change on communities and on intergroup and international relationships. Finally, we address the problem of inequity, the fact that certain populations are relatively more vulnerable to these mental health impacts compared to others.

IMPACTS ON INDIVIDUALS

Climate change has acute and chronic impacts, directly and indirectly, on individual well-being. Acute impacts result from natural disasters or extreme weather events. Chronic impacts result from longer term changes in climate. This discussion emphasizes the impacts experienced directly by individuals; however, it also touches on indirect impacts (witnessing others being impacted), which have profound implications for mental health.

ACUTE IMPACTS

Trauma and shock

Climate change-induced disasters have a high potential for immediate and severe psychological trauma from personal injury, injury or death of a loved one, damage to or loss of personal property (e.g., home) and pets, and disruption in or loss of livelihood. An early meta-analysis of studies on the relationship between disasters and mental health impacts found that between 7% and 40% of all subjects in 36 studies showed some form of psychopathology. General anxiety was the type of psychopathology with the highest prevalence rate, followed by phobic, somatic, and alcohol impairment, and then depression and drug impairment, which were all elevated relative to prevalence in the general population. More recent reviews concluded that acute traumatic stress is the most common mental health problem after a disaster. Terror, anger, shock, and other intense negative emotions are likely to dominate people’s initial response. Interview participants in a study about flooding conducted by Carroll, Morbey, Balogh, and Araoz (2009) used words such as “horrifying,” “panic stricken,” and “petrified“ to describe their experience during the flood

Post-traumatic stress disorder (PTSD)

For most people, acute symptoms of trauma and shock are reduced after conditions of security have been restored. However, many continue to experience problems as PTSD manifests as a chronic disorder. PTSD, depression, general anxiety, and suicide all tend to increase after a disaster.

For example, among a sample of people living in areas affected by Hurricane Katrina, suicide and suicidal ideation more than doubled, one in six people met the diagnostic criteria for PTSD, and 49% of people living in an affected area developed an anxiety or mood disorder such as depression. Similarly, 14.5% showed symptoms of PTSD from Hurricane Sandy, and 15.6% of a highly affected community showed symptoms of PTSD several years after experiencing extreme bushfire. PTSD is often linked to a host of other mental health problems, including higher levels of suicide, substance abuse, depression, anxiety, violence, aggresson, interpersonal difficulties, and job-related difficulties.

Incidence of PTSD is more likely among those who have lost close family members or property. Individuals who experience muitiple or long-lasting acute events, such as more than one disaster or multiple years of drought, are likely to experience more severe trauma and may be even more susceptible to PTSD and the other types of psychiatric symptoms described above. For example, a study showed that refugees exposed to multiple traumatic events experienced a higher rate of immediate and lifetime PTSD and had a lower probability of remission than refugees who had experienced few traumatic events. The likelihood of suicide is higher among those who have been exposed to more severe disasters.

Compounded stress

In general, climate change can be considered an additional source of stress to our everyday concerns, which may be tolerable for someone with many sources of support but can be enough to serve as a tipping point for those who have fewer resources or who are already experiencing other stressors. Stress manifests as a subjective feeling and a physiological response that occur when a person feels that he or she does not have the capacity to respond and adapt to a given situation. Thus, climate-related stress is likely to lead to increases in stress-related problems, such as substance abuse, anxiety disorders, and depression. These problems often carry economic costs incurred by lost work days, increased use of medical services, etc, which, in turn, create additional stress for individuals and society and have their own impacts on mental and physical health. Stress can also be accompanied by worry about future disasters and feelings of vulnerability, helplessness, mourning, grief, and despair. Following disasters, increased stress can also make people more likely to engage in behavior that has a negative impact on their health (e.g., smoking, risky behavior, and unhealthy eating habits; e.g. Stain et al. (2011) found that people living in a drought-affected area who had also recently experienced some other adverse life event were more likely to express a high degree of worry about the ongoing drought conditions. Although not as dramatic and acute a disaster as a hurricane, drought is associated with psychological distress, and one study found increased rates of suicide among male farmers in Australia during periods of prolonged drought. Several studies have found that many victims of a flood disaster express psychological distress even years after the flood.

Impacts of stress on physical health

High levels of stress and anxiety also appear to be linked to physical health effects.

For example, chronic distress results in a lowered immune system response, leaving people more vulnerable to pathogens in the air and water and at greater risk for a number of physical ailments. Sleep disorders also increase in response to chronic distress. Doppelt (2016) has described potential physiological responses to the stress of climate change, such as increased levels of the stress hormone cortisol, which, if prolonged, can affect digestion, lead to memory loss, and suppress the immune system. The World Heart Federation (2016) lists stress as a serious risk factor in developing cardiovascular disease.

Strains on social relationships

Particularly in home environments, disasters precipitate a set of stressors that can strain interpersonal interactions. A review of research on the impacts of natural disasters identified problems with family and interpersonal relations, as well as social disruption, concerns about the wider community, and feelings of obligation to provide support to others. Families whose homes are damaged by a flood, storm, or wildfire may need to be relocated, sometimes multiple times, before settling permanently. Family relationships may suffer. Separation from one another and from their systems of social support may occur. Children may have to attend a new school or miss school altogether; parents may find themselves less able to be effective caregivers. In addition, even those who are able to remain in their own home may still lose a sense of their home as a safe and secure environment. This has implications for interpersonal connections, as a home provides the context for social relationships. When the physical home is damaged, it changes the dynamic of the social relationships, often negatively. Domestic abuse, for example, including child abuse, often increases among families who have experienced disasters, such as Hurricane Katrina or the Exxon Valdez oil spill.

CHRONIC IMPACTS

Aggression and violence

The psychological impacts of warmer weather on aggression and violence have been extensively studied. Lab-based experiments and field-based surveys have demonstrated a causal relationship between heat and aggression. In other words, as the temperature goes up, so does aggression. This influenced researcher Craig Anderson (2012) to predict a demonstrable increase in violence associated with increased average temperatures. The relationship between heat and violence may be due to the impacts of heat on arousal, which results in decreases in attention and self-regulation, as well as an increase in the availability of negative and hostile thought, effect on cognitive function, which may reduce the ability to resolve a conflict without violence. Although this impact can manifest as an acute impact (e.g., as a result of a heat wave), due to the pervasive warming trends, and the shifting of climate zones, it is listed under chronic impacts.

Mental health emergencies

There is evidence that increases in mean temperature are associated with increased use of emergency mental health services. This is true not only in hot countries, like Israel and Australia, and in parts of the United States but also in relatively cooler countries, such as France and Canada. Higher temperatures have been linked to increased levels of suicide. It appears that the distress of feeling too hot can overwhelm coping ability for people who are already psychologically fragile. Climate emergencies can also exacerbate preexisting symptoms and lead to more serious mental health problems.

Loss of personally important places

Perhaps one of the best ways to characterize the impacts of climate change on perceptions is the sense of loss. Loss of relationship to place is a substantial part of this. As climate change irrevocably changes people‘s lived landscapes, large numbers are likely to experience a feeling that they are losing a place that is important to them, a phenomenon called solastalgia. This psychological phenomenon is characterized by a sense of desolation and loss similar to that experienced by people forced to migrate from their home environment. Solastalgia may have a more gradual beginning due to the slow onset of changes in one’s local environment. Silver and Grek-Martin (2015) described the emotional pain and disorientation associated with changes in the physical environment that were expressed by residents of a town damaged by tornadoes, even by residents who had not experienced personal loss.

Loss of place is not a trivial experience. Many people form a strong attachment to the place where they live, finding it to provide a sense of stability, security, and personal identity. People who are strongly attached to their local communities report greater happiness, life satisfaction, and optimism; whereas work performance, interpersonal relationships, and physical health can all be negatively affected by disruption to place attachment. For instance, Scannell and Gifford (2016) found that people who visualized a place to which they were attached showed improved self-esteem and sense of belonging relative to those who visualized a place to which they were not attached.

Climate change is likely to have a significant effect on human well-being by increasing migration. When people lose their home to rising sea levels, or when a home becomes unsuitable for human habitation due to its inability to support food crops, they must find another place to live. Although it is difficult to identify climate change as the causal factor in a complex sequence of events affecting migration, a common prediction is that 200 million people will be displaced due to climate change by 2050. Migration in and of itself constitutes a health risk. Immigrants are vulnerable to mental health problems, probably due to the accumulated stressors associated with the move, as well as with the condition of being in exile. Adger, Barnett, Brown, Marshall, and O‘Brien (2013) found being forced to leave one‘s home territory can threaten one’s sense of continuity and belonging. Because of the importance of connection to place in personal identity, such displacement can leave people literally alienated, with a diminished sense of self and increased vulnerability to stress. Although empirical research on the psychological impacts of migration is rare, Tschakert, Tutu, and Alcaro (2013) studied the emotional experience among residents of Ghana who were forced to move from the northern region of the country to the capital, Accra, because local conditions no longer supported their farming practices. Also, respondents expressed nostalgia and sadness for the home left behind and helplessness due to changes in their environments, such as deforestation, that were described as sad and scary.

Loss of autonomy and control

Climate change will intensify certain daily life inconveniences, which can have psychological impacts on individuals’ sense of autonomy and control. The desire to be able to accomplish basic tasks independently is a core psychological need, central to human well-being, and basic services may be threatened due to dangerous conditions. This may make mobility a challenge, particularly for the elderly and those with disabilities. Exposure to unwanted change in one’s environment can also reduce one’s sense of control over one’s life, which, in turn, has negative impacts on mental health.

Loss of personal and occupational identity

A more fundamental loss is the loss of personal identity tied to mundane aspects of daily life. Losing treasured objects when a home is damaged or destroyed is one way in which climate change can significantly impair an individual’s sense of self and identity. This is because objects help provide a continuing sense of who we are, particularly objects that represent important moments in life (e.g., journals), relationships (e.g., gifts or photographs), or personal family history (e.g., family heirlooms). Interviewees in a study conducted by Carroll et al. (2009) indicated that flood victims were particularly troubled by the loss of personal possessions, such as things they had made themselves or special things they had spent time and effort to procure or maintain. Although this may seem acute, the losses are permanent; the impacts are persistent and therefore become chronic.

A loss of identity associated with climate change is also sometimes attributable to its effect on place-bound occupations. This is likely due to the close relationship between identity and place-based occupations, like farming and fishing. Because severe storms and high temperatures disrupt economic activity climate change may have an effect on occupational identity in general. Loss of occupation has been associated with increased risk of depression following natural disaster.

Helplessness, depression, fear, fatalism, resignation, and ecoanxiety

Gradual, long-term changes in climate can also surface a number of different emotions, including fear, anger, feelings of powerlessness, or exhaustion. A review by Coyle and Van Susteren (2011) described cases in which fear of extreme weather approaches the level of phobia and the “unrelenting day-by-day despair” that can be experienced during a drought. Watching the slow and seemingly irrevocable impacts of climate change unfold, and worrying about the future for oneself, children, and later generations, may be an additional source of stress. Albrecht (2011) and others have termed this anxiety ecoanxiety. Qualitative research provides evidence that some people are deeply affected by feelings of loss, helplessness, and frustration due to their inability to feel like they are making a difference in stopping climate change. Some writers stress the possible detrimental impact of guilt, as people contemplate the impact of their own behavior on future generations. Although the impacts of climate change are not always visible, they perpetuate a delayed destruction that, like the damage to climate, are incremental and can be just as damaging as acute climate impacts.

IMPACTS ON COMMUNITY AND SOCIETY

In addition to the effects on individual health and wellbeing, climate change affects how individuals interact in communities and relate to each other. For example, natural disasters can have a negative impact on community bonds. A changing climate will likely affect aspects of community wellbeing, including social cohesion, aggression, and social relationships.

SOCIAL COHESION AND COMMUNITY CONTINUITY

Compounded stress from climate change has been observed among various communities. For example, CunsoLo Willox et al. (2013) examined the impacts of climate change on a small Inuit COMMUNITY. Members of the community, who all reported a strong attachment to the land, said they had noticed changes in the local climate and that these changes contributed to negative effects on themselves. As a result of altered interactions with the environment, community members reported food insecurity, sadness, anger, increased family stress, and a belief that their sense of self-worth and community cohesion had decreased. Elders expressed specific concern for the preservation of Inuit language and culture as they directly influence mental wellbeing and social cohesion.

Social cohesion and social capital can protect communities against mental and physical health impacts during a climate related disaster. Regardless of socioeconomic or cultural backgrounds, communities with high levels of social capital and community leadership experience the quickest recoveries after a disaster and the highest satisfaction with community rebuilding.

When locaI conditions become practically uninhabitable, ecomigration, leading to environmental refugees, can result. Such migrations erode social networks, as communities disperse in different directions. Because social networks provide important practical and emotional resources that are associated with health and wellbeing, the loss of such networks places people’s sense of continuity and belonging at risk. The current Syrian conflict, which has resulted in mass migration, may partially stem from climate change driven precipitation changes, rising mean sea levels, and a decrease in soil moisture. These climate impacts were exacerbated during the drought from 2007 to 2010 due to human disruptions within natural systems, leading to crop failure and large-scale conflict, hunger, and desperation. Although such civil unrest cannot be attributed to a single cause, recent evidence suggests climate-change caused drought may have played a significant role in the unraveling of an already vulnerable political and ecological climate.

AGGRESSION

Heightened anxiety and uncertainty about one’s own future can reduce the ability to focus on the needs of others, negatively impacting social relationships with friends and co-workers, as well as attitudes toward other people in general.

Interpersonal violence

High temperatures associated with climate change may increase people‘s aggressive tendencies. Aggression can also be exacerbated by decreased access to stress reducing green spaces and supportive social networks. Rising levels of frustration in society consequently lead to interpersonal aggression (such as domestic violence, assault, and rape). Ranson (2012) calculated that between 2010 and 2099, climate change would cause an estimated additional 30,000 murders, 200,000 cases of rape, and 3.2 million burglaries due to increased average temperatures.

Intergroup aggression

Climate change may increase conflict through several mechanisms. Violence may increase when competition for scarce natural resources increases or when ecomigration brings formerly separate communities into contact and they compete for resources, like jobs and land. In a recent metaanalysis, Hsiang, Burke, and Miguel (2013) found evidence that climate change can contribute to the frequency of intergroup violence (ie. political conflict and war). For example, in Houston, Texas, crime rates increased significantly following Hurricane Katrina, although Katrina migrants have not been definitively sourced as the cause. Meanwhile, restraints on crime weaken when existing social institutions are disrupted, thus increasing the probability of criminal behavior. For example, when government resources are devoted to damaged infrastructure from natural disasters, those resources may be diverted away from criminal justice systems, mental health agencies, and educational institutions, all of which tend to help mitigate crime. Agnew (2012) further pointed out that the effects of climate chanqe are likely to promote crime by “increasing strain, reducing social control, and weakening social support.”

Intergroup attitudes can also be negatively impacted by climate change. In a recent study, survey respondents displayed more negative attitudes toward policies to support minorities and immigrants when temperatures were high. An experimental study showed that people who were thinking about climate change became more hostile to individuals outside their social group (that is, people they consider to be unlike them) and more likely to support the status quo and its accompanying social inequities. Hostility toward individuals outside one’s social group can be a way of affirming one’s own group identity in the face of a perceived threat. In a vicious cycle, lower levels of social cohesion and connectedness, greater social inequalities, lack of trust between community members and for institutions, and other factors that inhibit community members from working together are associated with intergroup aggression.

THE PROBLEM OF INEQUITY

The impacts of climate change are not distributed equally. Some people will experience natural disasters firsthand, some will be affected more gradually over time, and some will experience only indirect impacts. This section describes some of the populations that are more vulnerable to the mental health impacts of climate change, including people who live in risk-prone areas, indigenous communities, low-income groups, certain communities of color, women, children, older adults, and people with disabilities or chronic illnesses. A thorough review of demographic differences in vulnerability to climate change can be found in Dodqen et al. (2016).

RISK-PRONE AREAS

Communities in which people’s livelihoods are directly tied to the natural environment, through agriculture, fishing, or tourism, are at greater risk. Some parts of the world are geologically more vulnerable to storms, rising seas, wildfires, or drought. There are detailed reports of farmers in Australia who have been negatively affected by prolonged periods of drought caused by changing weather patterns. Additionally, communities in low-lying areas, such as coastal Louisiana and islands in the Chesapeake Bay, are losing their land to erosion and rising seas. This past year, residents of Isle de Jean Charles, Louisiana, became the first climate refugees in the United States; a $48 million budget was allocated to relocate residents to a less flood-prone area, inhabitants of indigenous communities often depend on natural resources for their livelihoods and are located in geographically vulnerable regions.

Communities that lack resources, both physical and financial, can experience climate impacts more severely. This can be demonstrated by higher incidents of extreme weather within impoverished communities. In disasters, socioeconomically disadvantaged communities often suffer the most. For example, following Hurricane Sandy, lower income residents reported weak or absent social support networks and had the greatest percentages of severe mental distress and diagnosis of depression or anxiety after the hurricane. Furthermore, 35% of children living in a household that earns less than $20,000 annually experienced feelings of sadness, depression, fear, or nervousness following the hurricane.

INDIGENOUS COMMUNITIES

Indigenous communities are at risk of losing their cultural heritage, as well as their homes. Imperiled indigenous communities are found around the world, including the United States. In Alaska, for example, some native Alaskans have seen their villages literally vanish due to the thawing permafrost, and others are facing a similar outcome in the near future. For indigenous communities, climate change may threaten not oniy their physical home but also their lifestyle, including access to traditional food and culturally meaningful practices. Chief Albert Naquin of a Louisiana tribal community threatened by climate change stated, ”We’re going to lose all our heritage, all our culture”. Cunsolo, Willox et al. (2013) reviewed case studies of several Inuit communities and reported weakening social networks, increased levels of conflict, and significant stress associated with relocation or even thinking about relocation. In evocative language, Inuit community members interviewed by Durkalec et al. (2015) reported that an inability to go out on the sea ice (due to a changing climate) would make them feel like they “have no health” and ”can’t breathe,“ and they would ”be very sad,” “be lost,” or ”go crazy”.

The loss of any community is tragic, but the impact on native communities is particularly notable because it diminishes the cultural heritage and because indigenous communities are often defined by a special connection to the natural environment. This connection includes traditional patterns of behavior and environmental knowledge about the specific local ecosystem, knowledge that is disappearing, and about how to adapt to changing environments that could help us as a broader society as we adapt to the consequences of climate change.

CHILDREN AND INFANTS

Climate change has a big impact on young people. Children are more vulnerable to many of the effects due to their small size, developing organs and nervous systems, and rapid metabolisms. Children are more sensitive to temperature, because their physiological regulatory systems may be less effective (e.g., they sweat less) and because they are more likely to depend on others to help them regulate their behavior. Their small size makes very young children more susceptible to dehydration, and children under age five living in poverty represent 80% of victims of sanitation-related illnesses and diarrheal disease.

Climate impacts may have long-term and even permanent effects, such as changing the developmental potential and trajectory of a child. Currie and Almond (2011) reviewed evidence that even minor disturbances during childhood may have effects on health and earning potential that last into adulthood. Studies have shown that children who experience a flood or a drought during key developmental periods are shorter, on average, as adults. Fetuses are vulnerable to heat waves, with research shows that exposure to heat waves especially during the second and third trimesters of pregnancy leads to a lower average birth weight and possibly a greater incidence of preterm birth. Malnourishment or severe threat to health during the early years is associated with fewer years of schooling and reduced economic activity as adults, as well as with behavioral and motor problems and reduced IQ. Additionally, early exposure to disease provoked by climate change can have a major and permanent impact on neurological development, as can be dramatically seen in children exposed prenatally to the Zika virus.

Children can experience PTSD and depression following traumatic or stressful experiences with more severity and prevalence than adults. After climate events, children typically demonstrate more severe distress than adults. Furthermore, the prevalence of distress is also higher; higher rates of PTSD were found in children two years after a flood. Children’s mental health can also be affected not only by their experiences of stressors, such as natural disasters, extreme weather, and ecomigration, but also by the mental health of their caregivers. Children also have the potential to be emotionally affected if they become separated from their primary caregivers. Similar to physical experiences, traumatic mental experiences can have lifelong effects. Of course, early childhood is critical for brain development. Studies have documented that high levels of stress during childhood can affect the development of neural pathways, in ways that impair memory, executive function, and decision-making in later life.

Children are also at increased risk from disruptions to the educational system. Natural disasters, in particular can damage or destroy schools or make them inaccessible to teachers and students. After Hurricane Katrina, for example, 196,000 public school students had to change schools, and many of them missed a month or more of schooling. In this case, because the hardest-hit school districts were also some of the worst-performing ones, some students benefitted by transferring to better schools. However the effects on school achievement were negative.

Disasters may cause children to lose their social support networks to a greater extent. During adversity, people draw upon all of their personal resources, emotional and material. Although social networks can fill the gaps when individual resources become depleted during extreme trauma, the resources available from a tight-knit community may not go far, especially if the network is small or the community is poor. When disasters hit an area, they affect everyone and put entire neighborhoods in need of help. A study of children impacted by Hurricane Katrina found that those who were hit hardest by the storm also experienced less social support, likely because people in their immediate support network were themselves suffering.

DISADVANTAGED COMMUNITIES

Some communities of color are prone to experience increased impacts. A persistent reality in American culture is the existence of environmental injustice: Some racial and ethnic groups tend to be more exposed to environmental risks and to have fewer financial and political resources to buffer the impact. This is partly, but not completely, explained by economic status. Communities with fewer resources and greater exposure, for example, in Phoenix, Arizona, are likely to experience greater rates of high temperature impacts than majority groups. Lower-income communities are more likely to have outdated infrastructure, such as a lack of extreme weather warning systems, inadequate storm surge preparedness, and clogged or inadequate storm sewer systems, which places these communities at greater risk for the impacts of climate change. Areas with a high number of residents who lack access to health care or health insurance, or already experience poor health are more likely to be affected by climate change. Communities are also less resilient when they are weakened by social stressors, such as racism, economic inequality, and environmental injustices. Many of the communities in New Orleans that were affected by Hurricane Katrina possessed all of these characteristics, and the effects of racial disparities were clearly visible in the aftermath of the storm.

OCCUPATIONAL GROUPS

Certain lines and fields of work are more directly exposed to the impact of climate change. These occupations may include but not be limited to first responders, construction workers, health care workers, farmers, farm workers, fishermen, transportation workers, and utility workers. Inequitable health outcomes may arise directly through workers’ exposure to increased temperatures, air pollution, and extreme weather, and indirectly through vector-borne diseases, increased use of pesticides, and many other elements. According to the US Environmental Protection Agency, outdoor workers will be the first to endure the effects of climate change, as they will be exposed to extreme heat, which can cause heat stroke, exhaustion, and fatigue. As natural disasters occur more frequently, such as wildfires and flooding, firefighters and paramedics face increased safety risks. Agricultural workers face increased vulnerability to allergens, insects carrying diseases, such as West Nile, and pesticide exposure that are increased by changing weather and insect migration patterns.

ADDITIONAL POPULATIONS OF CONCERN

Individuals of all ages with disabilities or chronic mental or physical health issues may experience climate-related impacts at a greater extent. Often, people living with disabilities have disproportionately far lower access to aid during and after climate-related disasters. Those with mental health disorders can also experience exacerbated symptoms due to natural disasters. Degraded infrastructure creates barriers for people with mental illnesses to receive proper medical attention, leading to additional negative mental and physical health outcomes. For instance, following the 2012 Wisconsin heat wave, 52% of all heat-related deaths were among individuals with at least one mental illness. Half of those suffering from mental illness were taking psychotropic medications, which impede one’s ability to regulate one’s body temperature. These medications that treat mental illness are one of the main underlying causes of heat-related deaths. Additionally, those suffering from ongoing asthma and respiratory illnesses, like chronic obstructive pulmonary disease (COPD), are more sensitive to reduced air quality. Moreover, inequalities in the incidence of those who are chronically ill arise as a result of several socioeconomic factors.

Due to increased health and mobility challenges, the elderly are very susceptible to the risks of climate impacts. Higher rates of untreated depression and other physical illnesses reported among seniors contribute to this increased vulnerability. Research suggests the elderly, in particular, experience declines in cognitive ability when exposed to air pollution over the long ter. A study by Dominelii (2013) found that when infrastructure broke down (e.g., roads were impassable) due to floods. heat waves, or freeze-thaw events (all potentially climate-driven), formal care services were not available to vulnerable people, such as the elderly. They could not get to the services, and their normal services could not come through. Heat can have a particuIarly severe impact on the elderly and on people with pre-existing mental health problems; some of the medications associated with mental illness make people more susceptible to the effects of heat. Extreme temperatures or pollution can also make it more difficult for seniors to engage in regular outdoor activities, thus depriving them of the associated physical and mental benefits.

The stress directly related to supporting a child makes women more affected by climate change. Because of a mother’s frequent caregiver role, and because, on average, women have fewer economic resources than men, women may also be more affected, in general, by the stress and trauma of natural disasters. Possible loss of resources, such as food, water, shelter, and energy, may also contribute to personal stress. Epidemiological studies of post-disaster cohorts and the general population, suggest that women are more likely to experience mental health problems as a result of trauma. For example, the prevalence of PTSD in the general population is reported to be approximately twofold greater in women than in men.

BUILDING RESILIENCE

Developing plans to adapt and cope is critical in addressing the physical and psychological impacts of climate change. Resilience can be defined as the ability of a person (or a community) to cope with, grow through, and transcend adversity.

Climate change is no longer a distant, unimaginable threat; it is a growing reality for communities across the globe. Recognizing the risk, many local governments in the United States (as well as other places around the world) have created preparation or adaptation plans for shoring up physical infrastructure to withstand new weather and temperature extremes. These plans, while an important step, generally overlook the psycho-social impacts of a changing climate and do little to create or support the soft infrastructure needed for community psychological wellbeing. How can communities prepare themselves to minimize suffering and promote resilience in the face of the challenging impacts of climate change? Resilient communities can create the physical and social infrastructure that makes them less susceptible to negative effects.

On an individual level, resilience is built internally and externally through strategies, such as coping and self-regulation, and community social support networks. Most people come through adversity with positive adjustment and without psychopathology. In fact, some individuals may even experience what is called post-traumatic growth and come through a significant disruption with the feeling of having gained something positive, such as stronger social relationships or spectfic skills.

Even so, much can be done to increase the resilience capacity of individuals and communities, particularly in response to climate change.

Download the full report here.

The most intellectual creature to ever walk the Earth is destroying its only home – Dr. Jane Goodall.

We are experiencing the sixth great extinction, the situation is critical, in the last 40 years, we have lost some 60% of all animal and plant species on Earth.

Each species, no matter how insignificant it may seem, has a role to play in the rich tapestry of life, known today as biodiversity.

The huge global biodiversity losses now becoming apparent represent a crisis equalling and quite possibly surpassing climate change.

During my years studying chimpanzees in Gombe national park in Tanzania I experienced the magic of the rainforest. I learned how all life is interconnected, how each species, no matter how insignificant it may seem, has a role to play in the rich tapestry of life, known today as biodiversity. Even the loss of one thread can have a ripple effect and result in major damage to the whole.

Biodiversity describes the rich diversity of life on Earth, from individual species to entire ecosystems. The term was coined in 1985, a contraction of “biological diversity”, but the huge global biodiversity losses now becoming apparent represent a crisis equalling and quite possibly surpassing climate change. Deforestation, poaching, industrial farming and pollution are some of the ways in which the planet’s natural ecosystem is being disrupted, with devastating results.
Mother nature is being destroyed at an ever-faster rate for the sake of short term gain. This, along with our horrifying population growth, poverty, causing people to destroy the environment simply to try to make a living, and the unsustainable lifestyles of the rest of us who have way more than we need, is the root cause of all the planet’s woes.

How come the most intellectual creature to ever walk the Earth is destroying its only home?

. . . The Guardian

See also

CLIMATE SHOCK. The Economic Consequences of a Hotter Planet * THE SIXTH EXTINCTION. An Unnatural History * ARE WE IN THE MIDST OF THE SIXTH MASS EXTINCTION? A view from the world of amphibians

Electric food, the new scifi diet that could save our planet – George Monbiot.

The most important environmental action we can take is to reduce the area of land and sea used by farming and fishing. This means, above all, switching to a plant-based diet: research published in the journal Science shows that cutting out animal products would reduce the global requirement for farmland by 76%. It would also give us a fair chance of feeding the world. Grass-fed meat, contrary to popular belief, is no alternative: it is an astonishingly wasteful use of vast tracts of land that would otherwise support wildlife and wild ecosystems.

Could we go beyond even a plant-based diet? Could we go beyond agriculture itself? What if, instead of producing food from soil, we were to produce it from air? What if, instead of basing our nutrition on photosynthesis, we were to use electricity to fuel a process whose conversion of sunlight into food is 10 times more efficient?

This sounds like science fiction, but it is already approaching commercialisation. For the past year, a group of Finnish researchers has been producing food without either animals or plants. Their only ingredients are hydrogen-oxidising bacteria, electricity from solar panels, a small amount of water, carbon dioxide drawn from the air, nitrogen and trace quantities of minerals such as calcium, sodium, potassium and zinc. The food they have produced is 50% to 60% protein; the rest is carbohydrate and fat. They have started a company (Solar Foods) that seeks to open its first factory in 2021. This week it was selected as an incubation project by the European Space Agency.

. . .

The Guardian

Where the Water Wars of the future will be fought – Paul Ratner * An innovative approach to the assessment of hydro-political risk – F. Farinosia.

A new study from the European Commission’s Joint Research Centre (JRC) paints a disturbing picture of a nearby future where people are fighting over access to water. These post-apocalyptic sounding “water wars” could rise as a result of climate change and population growth and could become real soon enough if we don’t take steps to prevent them.

The study finds that serious conflicts over water are going to arise around the globe. The 5 hotspots identified by the paper include areas of the Nile, Ganges-Brahmaputra, Indus, Tigris-Euphrates, and Colorado rivers.

It’s still possible to change course if we are prepared to address the effects of climate change.

Likelihood of hydro-political issues among the main transboundary basins (transboundary basin borders in black, non-transboundary areas shaded).

Big Think

An innovative approach to the assessment of hydro-political risk:

A spatially explicit, data driven indicator of hydro-political issues.

F. Farinosia

Abstract

Competition over limited water resources is one of the main concerns for the coming decades. Although water issues alone have not been the sole trigger for warfare in the past, tensions over freshwater management and use represent one of the main concerns in political relations between riparian states and may exacerbate existing tensions, increase regional instability and social unrest.

Previous studies made great efforts to understand how international water management problems were addressed by actors in a more cooperative or confrontational way. In this study, we analyze what are the pre-conditions favoring the insurgence of water management issues in shared water bodies, rather than focusing on the way water issues are then managed among actors. We do so by proposing an innovative analysis of past episodes of conflict and cooperation over transboundary water resources (jointly defined as “hydro-political interactions”).

On the one hand, we aim at highlighting the factors that are more relevant in determining water interactions across political boundaries. On the other hand, our objective is to map and monitor the evolution of the likelihood of experiencing hydro-political interactions over space and time, under changing socioeconomic and biophysical scenarios, through a spatially explicit data driven index.

Historical cross-border water interactions were used as indicators of the magnitude of corresponding water joint-management issues. These were correlated with information about river basin freshwater availability, climate stress, human pressure on water resources, socioeconomic conditions (including institutional development and power imbalances), and topographic characteristics. This analysis allows for identification of the main factors that determine water interactions, such as water availability, population density, power imbalances, and climatic stressors.

The proposed model was used to map at high spatial resolution the probability of experiencing hydro-political interactions worldwide. This baseline outline is then compared to four distinct climate and population density projections aimed to estimate trends for hydro-political interactions under future conditions (2050 and 2100), while considering two greenhouse gases emission scenarios (moderate and extreme climate change).

The combination of climate and population growth dynamics is expected to impact negatively on the overall hydro-political risk by increasing the likelihood of water interactions in the transboundary river basins, with an average increase ranging between 74.9% (2050 – population and moderate climate change) to 95% (2100 – population and extreme climate change).

Future demographic and climatic conditions are expected to exert particular pressure on already water stressed basins such as the Nile, the Ganges/Brahmaputra, the Indus, the Tigris/Euphrates, and the Colorado.

The results of this work allow us to identify current and future areas where water issues are more likely to arise, and where cooperation over water should be actively pursued to avoid possible tensions especially under changing environmental conditions.

From a policy perspective, the index presented in this study can be used to provide a sound quantitative basis to the assessment of the Sustainable Development Goal 6, Target 6.5 “Water resources management”, and in particular to indicator 6.5.2 “Transboundary cooperation”.

View/download this study

Conclusion

In this paper, we presented an innovative analysis of the past hydro-political issues in international river basins and their determinants through the application of the Random Forest regression algorithm. Our analysis had two main goals: highlighting the factors that are more relevant in determining the hydro-political interactions, capturing also the non-linear relations between the main drivers; and producing a tool able to map and monitor the evolution of the hydro-political risk over space and time, under specific socioeconomic and biophysical scenarios.

We did that by designing an empirically estimated, data-driven, and spatially explicit global index of the magnitude of hydro-political issues. The factors that were found to be more relevant in determining hydro-political interactions were mainly represented by, respectively: population density, water availability (quantified through the Falkenmark index), upstream/downstream dynamics (represented by the flow accumulation), with territorial (area difference) and power imbalance (Composite Index of National Capability – CINC), and climatic conditions. Current climatic and socioeconomic conditions were used to design a baseline scenario of the distribution of the likelihood of hydro-political interactions. This output allows us to map the spatial distribution of the areas within the basins where water management issues are more likely to rise under current conditions.

Among the basins found to be more likely to experience water issues in this study, some were already identified as basin at risk in previous analyses, namely: Ganges/Brahmaputra, Pearl/Bei Jiang, Nile, Feni (or Fenney), Indus, Colorado, Tarim, Shatt al-Arab – Tigris/Euphrates, Hari, and Irrawaddy. The hereby proposed index adds the possibility to identify the most critical areas within the basin boundaries.

The baseline scenario was then compared to four distinct climate and population density projections, designed by combining the most updated bias corrected and spatially detailed climate and the most recent estimates of the future population changes. The results of this work allow the identification of the areas where water interactions are more likely to arise under present and upcoming conditions, and cooperation over water should be pursued to avoid possible hydro-political tensions. Future demographic and climatic conditions are expected to heavily increase the probability of experiencing water management issues in already stressed basins, such as the Nile, the Indus, the Colorado, the Feni, the Irrawaddy, the Orange, and the Okavango.

One of the characteristics of the analysis presented is that we chose not to make a distinction between past episodes of cooperation and dispute over water, using them collectively as water interactions, a measure of the magnitude of the associated water issue. This was motivated by the fact that water disputes had virtually never ended in violent conflicts, at least in the most recent historical eras, and by the consideration that the classification of positive (cooperative) and negative (conflictive) interactions in the event databases has often been arbitrary and ambiguous.

Our focus was then more oriented towards understanding the preconditions increasing the likelihood of experiencing hydro-political interactions due to emerging water management issues. More than being exhaustive, our approach tends to boost the interest in the hydro-political field of study, by offering a new perspective through the application of a methodology that had never been considered before in this kind of analyses, dealing with aspects that are different by the only institutional resilience, and by exploring the possibility of creating a spatially explicit interactive tool able to assist stakeholders and policy makers in dealing with water related issues in different socioeconomic and climatic contexts through the analysis of what-if scenarios. Future studies could further develop the instrument by integrating updated socioeconomic, biophysical, and demographic projections.

The difficulties and the limitations encountered in this process were multiple. Beside the logical constraints that every global analysis has, as the other studies in this field, this work is affected by limitations in data availability. Water events database are extremely hard and expensive to collect and to manage. Data collection is mostly conducted through the application of mining algorithms operating in the news databases available only in the most widely spoken western languages. For this reason, the available datasets are necessarily biased and incomplete. Their temporal coverage is very limited, only eleven years in our case, and the sub-national geographic characterizations of the specific water related events is, in the majority of the cases, not considered. These particular factors make very difficult to apply the existing datasets for the development of spatially explicit interactive decision makingtools.

As stated above, the index presented in this paper could be applied for the Agenda 2030 monitoring activities and in particular for Target 6.5 – Water Resources Management, where the only indicator regarding hydro-political dynamics used is the 6.5.2 Proportion of transboundary basin area with an operational arrangement for water cooperation. This is an indicator capturing mainly the institutional resilience in transboundary basins, with no consideration for the other determining factors specifically analyzed in this study. Therefore, the use of the proposed index could provide a substantial contribution to move from the mere recording of facts, to the understanding of phenomena the mechanisms behind them, which are prerequisites for identification of effective sustainability policies.

As noted already in previous global analyses (Bernauer and Böhmelt, 2014; De Stefano et al., 2017; Yoffe et al., 2003), the results of this study should be intended to be an indicator of the areas that might require closer investigation under present and possible upcoming scenarios. We recommend to further explore the development of this analysis in regional or sub-regional contexts where more detailed data is available.

Future research will be focused in specific transnational river basins in developing countries where potential water stress, exacerbated by climate change and variability, rapid population growth, and unsustainable development could be further destabilizing factors for the already tumultuous political context.

Science Direct

Avoiding meat and dairy is the ‘single biggest way’ to reduce your impact on Earth – Damian Carrington.

Biggest analysis to date reveals huge footprint of livestock, it provides just 18% of calories but takes up 83% of farmland.

86% of all land mammals are now livestock or humans.

Avoiding meat and dairy products is the single biggest way to reduce your environmental impact on the planet, according to the scientists behind the most comprehensive analysis to date of the damage farming does to Earth.

The new research shows that without meat and dairy consumption, global farmland use could be reduced by more than 75%, an area equivalent to the US, China, European Union and Australia combined and still feed the world. Loss of wild areas to agriculture is the leading cause of the current mass extinction of wildlife.

The new analysis shows that while meat and dairy provide just 18% of calories and 37% of protein, it uses the vast majority, 83%, of farmland and produces 60% of agriculture’s greenhouse gas emissions. Other recent research shows 86% of all land mammals are now livestock or humans. The scientists also found that even the very lowest impact meat and dairy products still cause much more environmental harm than the least sustainable vegetable and cereal growing.

The study, published in the journal Science, created a huge dataset based on almost 40,000 farms in 119 countries and covering 40 food products that represent 90% of all that is eaten. It assessed the full impact of these foods, from emissions, freshwater use and water pollution (eutrophication) and air pollution (acidification).

“A vegan diet is probably the single biggest way to reduce your impact on planet Earth, not just greenhouse gases, but global acidification, eutrophication, land use and water use,” said Joseph Poore, at the University of Oxford, UK, who led the research. “It is far bigger than cutting down on your flights or buying an electric car,” he said, as these only cut greenhouse gas emissions.

“Agriculture is a sector that spans all the multitude of environmental problems,” he said. “Really it is animal products that are responsible for so much of this. Avoiding consumption of animal products delivers far better environmental benefits than trying to purchase sustainable meat and dairy.”

The analysis also revealed a huge variability between different ways of producing the same food. For example, beef cattle raised on deforested land result in 12 times more greenhouse gases and use 50 times more land than those grazing rich natural pasture. But the comparison of beef with plant protein such as peas is stark, with even the lowest impact beef responsible for six times more greenhouse gases and 36 times more land.

The large variability in environmental impact from different farms does present an opportunity for reducing the harm, Poore said, without needing the global population to become vegan. If the most harmful half of meat and dairy production was replaced by plant based food, this still delivers about two-thirds of the benefits of getting rid of all meat and dairy production.

Cutting the environmental impact of farming is not easy, Poore warned: “There are over 570m farms all of which need slightly different ways to reduce their impact. It is an [environmental] challenge like no other sector of the economy.” But he said at least $500bn is spent every year on agricultural subsidies, and probably much more: “There is a lot of money there to do something really good with.”

Labels that reveal the impact of products would be a good start, so consumers could choose the least damaging options, he said, but subsidies for sustainable and healthy foods and taxes on meat and dairy will probably also be necessary.

One surprise from the work was the large impact of freshwater fish farming, which provides two-thirds of such fish in Asia and 96% in Europe, and was thought to be relatively environmentally friendly. “You get all these fish depositing excreta and unconsumed feed down to the bottom of the pond, where there is barely any oxygen, making it the perfect environment for methane production,” a potent greenhouse gas, Poore said.

The research also found grass fed beef, thought to be relatively low impact, was still responsible for much higher impacts than plant based food. “Converting grass into meat is like converting coal to energy. It comes with an immense cost in emissions,” Poore said.

The new research has received strong praise from other food experts. Prof Gidon Eshel, at Bard College, US, said: “I was awestruck. It is really important, sound, ambitious, revealing and beautifully done.”

He said previous work on quantifying farming’s impacts, including his own, had taken a topdown approach using national level data, but the new work used a bottom-up approach, with farm-by-farm data. “It is very reassuring to see they yield essentially the same results. But the new work has very many important details that are profoundly revealing.”

Prof Tim Benton, at the ‘ University of Leeds, UK, said: “This is an immensely useful study. It brings together a huge amount of data and that makes its conclusions much more robust. The way we produce food, consume and waste food is unsustainable from a planetary perspective. Given the global obesity crisis, changing diets, eating less livestock produce and more vegetables and fruit has the potential to make both us and the planet healthier.”

Dr Peter Alexander, at the University of Edinburgh, UK, was also impressed but noted: “There may be environmental benefits, eg for biodiversity, from sustainably managed grazing and increasing animal product consumption may improve nutrition for some of the poorest globally. My personal opinion is we should interpret these results not as the need to become vegan overnight, but rather to moderate our meat consumption.”

Poore said: “The reason I started this project was to understand if there were sustainable animal producers out there. But I have stopped consuming animal products over the last four years of this project. These impacts are not necessary to sustain our current way of life. The question is how much can we reduce them and the answer is a lot.”

The Commonwealth can kickstart a global offensive on climate Change – Jacinda Ardern.

The task ahead is immense, but New Zealanders know it can be achieved. We have a proud history of this kind of leadership.

Leaders of Commonwealth nations are meeting in London this week instead of the South Pacific nation of Vanuatu because things did not go according to plan. In 2015, cyclone Pam roared across Vanuatu, knocking out power, crippling water systems and levelling homes, schools and churches.

In only 24 hours, the storm dashed the island nation’s hopes of hosting the Commonwealth summit. Three years later, many communities have yet to fully recover, in a place where the impact of a changing climate is on full display.

Vanuatu is one of New Zealand’s Pacific neighbours and friends and its experience is an increasingly common one. In February, Tonga was hit by its worst cyclone in decades, cyclone Gita. When I visited the country in March, I spent time with schoolchildren who were learning in tents, the roof of their school had been blown off and the classroom walls destroyed by the storm.

Such extreme weather events are tragedies. They are also provocations. They tell us that climate change is not a theory, or a projection, but something that is already happening. They tell us we must be more ambitious when it comes to tackling this urgent global challenge.

The Commonwealth heads of government meeting is a good place to start. Twenty eight years ago, the same meeting produced the Langkawi declaration on the environment, among the first collective statements to cite greenhouse gas emissions as one of the chief problems facing the world. I am confident that this year’s gathering can be just as decisive by fostering bold commitments to step up climate action.

And while the task ahead is immense, New Zealanders know it can be achieved because we have a proud history of leadership on challenges than can seem too hard to contemplate.

We were the first country in which women won the right to vote, we were at the forefront of the anti nuclear movement, and we were at the table when the United Nations was born. And we are ready to lead on climate change, the defining challenge of our generation.

That is why my government has committed to setting an ambitious new target of achieving carbon neutrality by 2050. In June, we are starting a consultation process on how to enshrine this commitment in law.

Our plan includes an expert Independent Climate Commission which will develop carbon budgets through to 2050 setting a path to carbon neutrality that maintains enough energy to run our economy and country. Along the way, we are committed to helping regions and industries directly affected by the transition move away from fossil fuels, with billions of dollars of investment in local infrastructure and clean energy projects on the horizon. We are also active in building international cooperation on climate action.

Nearly half of New Zealand’s emissions come from our world renowned farming sector. This is why we lead the 49 nation Global Research Alliance that is developing techniques to reduce agricultural emissions without compromising food security. And that is why we are committed to helping other countries achieve more climate friendly agricultural production, in ways that will increase farmers’ yields and build resilience while reducing emissions.

Alongside the UK, we belong to coalitions of forward thinking countries and cities pressing to phase out coal generation, eliminate harmful subsidies that encourage wasteful fossil fuel use, and help our economies transition to carbon neutrality.

The international consensus on climate change in Paris in 2015 was a historic achievement. Now we all need to do our part by delivering on what we signed up to.

This means setting ambitious and concrete goals, like New Zealand’s plan to achieve 10000 renewable electricity generation by 2035. And it means agreeing on the finer details around holding countries accountable for reaching their Paris targets.

Leadership on climate change cannot be left to the big economies. It demands broad and deep action. New Zealand contributes less than 1% of global emissions. Yet together the world’s small emitters account for about a quarter of global emissions. History calls on us to play our part.

At this week’s Commonwealth meeting, I’ll be thinking about Vanuatu’s experience and the summit that couldn’t happen. I’ll also be guided by a Maori saying from my country Mo tatou, a, mo ka uri, a muri ake neighbour, for us and for our children after us.

That is what’s at stake when we talk about climate Change, the world we’ll leave for the generations that follow us. They are why we need to act now, with purpose and courage.

*

Jacinda Ardern is the prime minister of New Zealand

CLIMATE SHOCK. The Economic Consequences of a Hotter Planet – Gernot Wagner and Martin L. Weitzman * THE SIXTH EXTINCTION. An Unnatural History – Elizabeth Kolbert * ARE WE IN THE MIDST OF THE SIXTH MASS EXTINCTION? A view from the world of amphibians – David B. Wake and Vance T. Vredenburg.

Combating climate change is the race of our lifetime. That much, at least, is clear. And it’s not just any race. It’s a race of uncertain length, and uncertain stakes. None of that means it isn’t one worth tackling. Indeed, while the danger is grave, climate change also provides opportunities to act, and, yes, to profit. The Chinese word for “crisis” is famously made up of two characters: that for danger (危), and that for opportunity (机).

Gernot Wagner & Martin L. Weitzman.

Yes, China is adding many tons of pollution to the atmosphere through its rapid building of fossil-fueled energy. But China is also at the forefront of the search for solutions. Following the Chinese tradition of “shidian” (试点), wherein prior to launching a large government program it first ought to be tested in multiple regions through a series of pilots, China is now experimenting with several regional cap-and-trade systems. These pilots may well be a metaphor for tackling climate change more broadly. No single piece of legislation, no single technology will solve it all. Climate change most likely won’t create one trillionaire. Rather, it will turn many, many tinkerers and inventors in their proverbial garages into multi-millionaires, each of whom will solve a piece of the overall puzzle.

These innovative solutions are cropping up as we speak, often aided by the right kinds of policies. The rapid price decline of solar photovoltaic technologies is but one example. It is precisely this interplay of smart policy and smart technology that will lead to the kinds of clean energy breakthroughs necessary to match the magnitude of the problem. Indeed, it’s a virtuous circle of clean technology making the right kinds of policies more likely, and policy returning the favor. China’s commitment to begin capping greenhouse gas emissions from industry and energy is a significant step in the right direction. So is the U.S. Clean Power Plan, for the first time limiting emissions from power plants.

The Paris Climate Agreement builds an important foundation for much more action to come. As it must. Little that has happened over the past year—policies in Beijing, Washington, and Paris included—has changed the basic climate calculus. The forces pointing toward the necessity for much more significant action on the mitigation front are as strong as ever. So are the forces pointing toward solar geoengineering.

The “shock” in Climate Shock is real. So is the opportunity. All that begins with taking the economics seriously.

Preface

Pop Quiz TWO QUICK QUESTIONS:
– Do you think climate change is an urgent problem?
– Do you think getting the world off fossil fuels is difficult?

If you answered “Yes” to both of these questions, welcome. You’ll nod along, on occasion even cheer, while reading this book. You’ll feel reaffirmed. You are also in the minority. The vast majority of people answer “Yes” to one or the other question, but not both. If you answered “Yes” only to the first question, you probably think of yourself as a committed environmentalist.

You may think climate change is the issue facing society. It’s bad. It’s worse than most of us think. It’s hitting home already, and it will strike us with full force. We should be pulling out all the stops: solar panels, bike lanes, the whole lot. You’re right, in part. Climate change is an urgent problem. But you’re fooling yourself if you think getting off fossil fuels will be simple. It will be one of the most difficult challenges modern civilization has ever faced, and it will require the most sustained, well-managed, globally cooperative effort the human species has ever mounted.

If you answered “Yes” only to the second question, chances are you don’t think climate change is the defining problem of our generation. That doesn’t necessarily mean you’re a “skeptic” or “denier” of the underlying scientific evidence; you may still think global warming is worthy of our attention.

But realism dictates that we can’t stop life as we know it to mitigate a problem that’ll take decades or centuries to show its full force. Look, some people are suffering right now because of lack of energy. And whatever the United States, Europe, or other high emitters do to rein in their energy consumption will be nullified by China, India, and the rest catching up with the rich world’s standard of living. You know there are trade-offs.

You also know that solar panels and bike lanes alone won’t do. You, too, are right, but none of that makes climate change any less of a problem. The long lead time for solutions and the complex global web of players are precisely why we must act decisively, today. If you are an economist, chances are you answered “Yes” to the second question. Standard economic treatments all but prescribe the stance of the “realist.” After all, economists live and breathe trade-offs. Your love for your children may go beyond anything in this world, but as economists we are obligated to say that, strictly speaking, it’s not infinite. As a parent, you may invest enormous sums of money and time into your children, but you, too, face trade-offs: between doing your day job and reading bedtime stories, between indulging now and teaching for later.

Trade-offs are particularly relevant on an average, national, or global level. And they are perhaps nowhere more apparent on the planetary scale than in the case of climate change. It’s the ultimate battle of growth versus the environment.

Stronger climate policy now implies higher, immediate economic costs. Coal-fired power plants will become obsolete sooner or won’t be built in the first place. That comes with costs, for coal plant owners and electricity consumers alike. The big trade-off question then is how these costs compare to the benefits of action, both because of lower carbon pollution and because of economic returns from investing in cleaner, leaner technologies today. Economists often cast themselves as the rational arbiters in the middle of the debate. Our air is worse now than it was during the Stone Age, but life expectancy is a lot higher, too. Sea levels are rising, threatening hundreds of millions of lives and livelihoods, but societies have moved cities before. Getting off fossil fuels will be tough, but human ingenuity—technological change—will surely save the day once again. Life will be different, but who’s to say it will be worse.

Markets have given us longer lives and untold riches. Let properly guided market forces do their magic. There’s a lot to be said for that logic. But the operative words are “properly guided.” What precisely are the costs of unabated climate change? What’s known, what’s unknown, what’s unknowable? And where does what we don’t know lead us?

That last question is the key one: Most everything we know tells us climate change is bad. Most everything we don’t know tells us it’s probably much worse. “Bad” or “worse” doesn’t mean hopeless. In fact, almost every prediction in this book is prefaced by a version of the words unless we act. We don’t venture predictions only to see them become true. We talk about where unfettered economic forces may lead in order to guide them in a more productive, better direction.

And guide we can. In many ways, putting a proper price on carbon isn’t a question of if, it’s a question of when.

Climate Shock

CHAPTER 1

911 THANK RUSSIAN POLICE CORRUPTION for footage that eluded NASA and every other space agency. On February 15, 2013, an asteroid as wide as 20 meters (66 feet) exploded in the sky above the Russian city of Chelyabinsk during the morning commute hours, causing a blast brighter than the sun. It didn’t take long for some spectacular videos to appear online, mostly from dashboard cameras many Russian drivers have to protect themselves against the whims of traffic cops. The blast injured 1,500, most because of glass shattered by the explosion.

It was a sobering wakeup call for space agencies to ramp up their asteroid detection and defense capabilities. The money for such efforts is perennially in short supply. But the technical means are there, or at least they could be. A U.S. National Academy study estimates it would take ten years and around $2 or 3 billion to launch a test to deflect an asteroid bound to hit Earth.

It may not be as glamorous as sending a man to the moon within the decade, but it may be at least as important. While the Chelyabinsk asteroid would have been too small to deflect, it would have still been nice to know about it in advance. The chance of a larger asteroid hitting us is small, but it’s there. Educated guesses put it as a 1-in-1,000-year event. That’s a 10 percent chance each century. We haven’t yet spent the money to know for sure.

The fact, though, is that a few billion dollars would allow NASA and others both to catalogue the hazards and to defend against them. That’s a small amount when measured against the costs of a potentially civilization-destroying threat.

Around 65 million years ago it was a giant asteroid that caused the globe’s fifth major extinction event, the dinosaurs. Climate change isn’t exactly hurtling toward us through outer space. It’s entirely homegrown. But the potential devastation is just as real. Elizabeth Kolbert argues convincingly based on her book The Sixth Extinction how this time around: “We are the asteroid.” In fact, by one recent scientific assessment, we are slated to experience global changes at rates that are at least ten times faster than at any point in the past 65 million years.

As Hurricane Sandy was whipping the Eastern Seaboard, leaving Manhattan below the Empire State Building partially flooded and almost entirely without power, New York governor Andrew Cuomo wryly told President Barack Obama that: “We have a 100-year flood every two years now.” Hurricane Irene in August 2011 caused the first-ever preemptive weather-related shutdown of the entire, century-old New York City subway and bus system. It took only fourteen months for the second shutdown. Sandy hit in October 2012. All told, Irene killed 49 and displaced over 2.3 million. Sandy killed 147 and displaced 375,000. New York, of course, is far from unique here.

Typhoon Haiyan slammed the Philippines in November 2013, killing at least 6,000 people and displacing four million. Not even a year earlier, Typhoon Bopha struck the country, killing over a thousand and displacing 1.8 million.

The European summer heat wave in 2003 killed 15,000 in France alone, over 70,000 in Europe.

The list goes on, spanning both poor and rich countries and continents. Society as a whole—especially in rich places like the United States and Europe—has never been as well equipped to cope with these catastrophes as it is today. As is so often the case, the poor suffer the most. That makes these recent deaths and displacements in places like New York all the more remarkable.

What likens these storms and other extreme climatic events to asteroids is that they both can be costly, in dollars and in deaths. The important and clear differences show that the climate problem is costlier still.

First the obvious: Major storms have hit long before humans started adding carbon dioxide to the atmosphere.

However, warmer average temperatures imply more energy in the atmosphere implies more extreme storms, floods, and droughts. The waters off the coast of New York were 3°C (5.4°F) warmer than average during the days before Sandy. The waters off the coast of the Philippines were 3°C (5.4°F) warmer than average just as Haiyan was intensifying on its path to make landfall. Coincidence? Perhaps.

The increase off New York happened at the surface. The increase off the Philippines happened 100 meters (330 feet) below. But the burden of proof seems to rest on those questioning the link from higher temperatures to more intense storms. That’s particularly true, since the best research goes much beyond drawing circumstantial links. The science isn’t settled yet, but the latest research suggests that climate change will lead both to more and bigger storms. Though hurricanes are among the toughest climatic events to link directly to climate change, mainly because of how rare they are. It’s easier to draw the direct link from climate change to more common events like extreme temperatures, floods, and droughts.

Think of it like drunk driving: Drinking increases the chance of a car crash, but plenty of crashes happen without elevated blood alcohol levels. Or liken it to doping in sports: No single Barry Bonds home run or Lance Armstrong Tour de France stage win can be attributed to doping, nor did doping act alone. Bonds still had to hit the ball, and Armstrong still had to pedal. But doping surely helped them hit farther and bike faster.

Major storms, like home run records and multiple Le Tour wins, have happened before. None of that means steroids or elevated levels of red blood cells in an athlete’s blood had no effect.

Something similar holds for elevated levels of carbon dioxide in the atmosphere. Researchers are getting increasingly better at using “attribution science” to identify the human footprint even in single events. The UK’s National Weather Service, more commonly known as the Met Office, has a Climate Monitoring and Attribution team churning out studies that do just that.

One such study found with 90 percent confidence that “human influence has at least doubled the risk of a heatwave exceeding [a] threshold magnitude” of mean summer temperature that was met in Europe in 2003, and in no other year since 1851. Links will only become clearer in the future, both because the science is getting better and because extreme weather events are becoming ever more extreme.

Governor Cuomo’s “100-year flood every two years” comment may have been a throw-away line, but he was on to something. By the end of the century, we can expect today’s 100-year flood to hit as frequently as once every three to twenty years.

That’s a century out, long after our lifetimes, but we know that we can’t wait that long to act. Already, the annual chance of storm waters breaching Manhattan seawalls has increased from around 1 percent in the 19th century to 20 to 25 percent today. That means lower Manhattan can expect some amount of flooding every four to five years. Unlike with asteroids, there’s no $2-to-3-billion, ten-year NASA program to avoid the impact of storms and other extreme climatic events like floods and droughts. Nor is there a quick fix for less dramatic events like the ever faster rising seas. As a first line of defense, higher seawalls would surely help.

But they can go only so far for so long. Higher seas make storm surges all the more powerful, and higher seas themselves come with plenty of costs of their own. Imagine standing in the harbor of your favorite coastal city.

Then imagine standing there at the end of the century with sea levels having risen by 0.3 to 1 meters (1 to 3 feet). It will only be a matter of time before higher seawalls won’t do, when the only option will be retreat. By then, it will be too late to act. We can’t re-create glaciers and polar ice caps, at least not in human timescales. The severity of the problems will have been locked in by past action, or lack thereof. Future generations will be largely powerless against their own fate.

One possible response that attempts to provide a quick fix is large-scale geoengineering: shooting small reflective particles into the stratosphere in an attempt to cool the planet. Geoengineering is far from perfect. It comes with lots of potential side effects, and it’s no replacement for decreasing emissions in the first place. Still, it may be a useful, temporary complement to more fundamental measures. (We will start exploring the full implications of geoengineering in chapter 5.)

None of what we’ve talked about thus far even deals with the true worst-case scenarios. Having the climatic equivalent of ever more Chelyabinsk-like asteroids hit us is bad, but there are ways to cope. For relatively small asteroids, it’s seeking shelter and moving away from windows. For relatively small climatic changes, it’s moving to slightly cooler climates and higher shores. That’s often easier said than done, but at least it’s doable. For much more dramatic climatic consequences—such as a crippling of the world’s productive agricultural lands—it’s tough to imagine how we’d cope in a way that wouldn’t cause serious disruptions.

Meanwhile, standard economic models don’t include much of this thinking. Many observers regard average global warming of greater than 2°C (3.6°F) above preindustrial levels as having the potential to trigger events deserving of various shades of the label “catastrophe.” Economists typically have a hard time making sense of that term. They need dollar figures. Does a catastrophe then cost 10 percent of global economic output? 50 percent? More?

While it’s indeed necessary to translate impacts into dollars and cents, such benefit-cost analyses can act as only one guide for how society ought to respond. We should also take into account the potential for planet-as-we-know-it-altering changes in the first place. First and foremost, climate change is a risk management problem—a catastrophic risk management problem on a planetary scale, to be more precise.

CAMELS IN CANADA

If one wanted to imagine an all but intractable public policy problem, climate change would be pretty close to the ideal. Today’s storms, floods, and wildfires notwithstanding, the worst effects of global warming will be felt long after our lifetimes, likely in the most unpredictable of ways. Climate change is unlike any other environmental problem, really unlike any other public policy problem. It’s almost uniquely global, uniquely long-term, uniquely irreversible, and uniquely uncertain—certainly unique in the combination of all four.

These four factors, call them the Big Four, are what make climate change so difficult to solve. So difficult that—short of a major jolt of the global, collective conscience—it may well prove too difficult to tackle climate change just by decreasing emissions and adjusting to some of the already unavoidable consequences. At the very least we’ll need to add suffering to the list. The rich will adapt. The poor will suffer.

Then there’s the almost inevitable-sounding geoengineering, attempting a global-scale techno fix for a seemingly intractable problem. The most prominent geoengineering idea would have us deliver tiny sulfur-based particles into the stratosphere in an attempt to engineer an artificial sun shield of sorts to help cool the planet. Everything we know about the economics of climate change seems to point us in that direction.

Geoengineering is so cheap to do crudely, and it has such high leverage, that it almost has the exact opposite properties of carbon pollution. It’s the “free-rider” effect of carbon pollution that has caused the problem: it’s in no one’s narrow self-interest to do enough. It’s the “free-driver” effect that may push us to geoengineer our way out of it: it’s so cheap that someone will surely do it based on their own self-interest, broader consequences be damned. But let’s not go there quite yet.

Let’s first tackle The Big Four in turn, beginning with why climate change is the ultimate “free-rider” problem: Climate change is uniquely global. Beijing’s smog is bad. So bad, that it comes with real and dramatic health effects that have prompted city officials to close schools and take other drastic actions.

But Beijing’s smog—or that in Mexico City or Los Angeles, for that matter—is mostly confined to the city. Chinese soot may register at measuring stations on the U.S. West Coast, much like Saharan dust may on occasion blow to central Europe. But all these effects are still regional.

That’s not true for carbon dioxide. It doesn’t matter where on the planet a ton is being emitted. Impacts may be regional, but the phenomenon is global and—among environmental problems—almost uniquely so. The ozone hole over the Antarctic is bad, but even at its height it has never reached the level of engulfing the globe. The same goes, say, for biodiversity loss or deforestation. These are regional problems. It’s climate change that ties them together into phenomena with global implications.

The global nature of global warming is also Strike One against enacting sensible climate policy. It’s tough enough to get voters to enact pollution limits on themselves, when those limits benefit them and only them, and when the benefits of action outweigh the costs. It’s a whole lot tougher to get voters to enact pollution limits on themselves if the costs are felt domestically but the benefits are global: a planetary “free-rider” problem.

Climate change is uniquely long-term. The past decade was the warmest in human history. The one before was the second-warmest. The one before that was the third-warmest. “Americans are noticing changes all around them,” as the 2014 U.S. National Climate Assessment puts it.

Changes are nowhere as evident as above the Arctic Circle: Arctic sea ice has lost half of its area and three-quarters of its volume in only the past thirty years. The Foreign Policy article describing “The Coming Arctic Boom” takes all of this as given. Then there are the visible changes all around. Again, from the National Climate Assessment: “Residents of some coastal cities see their streets flood more regularly during storms and high tides. Inland cities near large rivers also experience more flooding, especially in the Midwest and Northeast. Insurance rates are rising in some vulnerable locations, and insurance is no longer available in others. Hotter and drier weather and earlier snowmelt mean that wildfires in the West start earlier in the spring, last later into the fall, and burn more acreage.”

Climate change is here, and it’s here to stay. None of that should mask the fact that most of the worst consequences of climate change are still remote, often caged in global, long-term averages: global average surface temperature projections for 2100, or global average sea level projections for decades and centuries out.

Strike Two against sensible climate policy: the worst effects are far off—never mind that avoiding these predictions would entail acting now.

Climate change is uniquely irreversible. Even if we stopped emitting carbon tomorrow, we would have decades of warming and centuries of sea-level rise locked in. The eventual, full melting of large West Antarctic ice sheets may already be unstoppable. More extreme weather events are already here and will be with us for some time to come.

Strike Three. Over two-thirds of the excess carbon dioxide in the atmosphere that wasn’t there when humans started burning coal will still be present a hundred years from now. Well over one-third will still be there in 1,000 years. These changes are long-term, and—at least in human timescales—virtually irreversible.

Strike Four. As if three strikes weren’t enough, there’s another unique characteristic of climate change to round out the Big Four, and it may be the biggest one of them all: uncertainty—everything we know that we don’t know, and perhaps more importantly, what we don’t yet know we don’t know.

Last time concentrations of carbon dioxide were as high as they are today, at 400 parts per million (ppm), the geological clock read “Pliocene.” That was over three million years ago, when natural variations, not cars and factories, were responsible for the extra carbon in the air. Global average temperatures were around 1–2.5°C (1.8 to 4.5°F) warmer than today, sea levels were up to 20 meters (66 feet) higher, and camels lived in Canada. We wouldn’t expect any of these dramatic changes today.

The greenhouse effect needs decades to centuries to come into full force. Despite the recent changes in the Arctic, ice sheets need decades to centuries to melt. Global sea levels take decades to centuries to adjust accordingly. Carbon dioxide concentrations may have been at 400 ppm three million years ago, whereas rising sea levels lagged decades or centuries behind. That time difference is important and points to the long-term nature and irreversibility of it all. See strikes two and three.

But all that’s small consolation, and there’s an important twist to strike four.

DEEP UNCERTAINTIES

The best available climate models come close in their temperature projections to what the world experienced during the Pliocene, but they aren’t predicting sea levels of 20 meters (66 feet) higher. Nor do they predict camels wandering around Canada. Not now. Not hundreds of years from now. That’s true for two important reasons.

First, most climate models are unduly skewed toward the known, sometimes making them much too conservative. Until recently, most climate models predicted rising sea levels only based on thermal expansion of the oceans (and the melting of mountain glaciers), but they did not include the effects of melting ice sheets.

Warmer waters take up more space, leading to higher sea levels. That mechanism alone has indeed contributed to over a third of sea-level rise in the past two decades. It’s also clear that melting glaciers in Greenland and Antarctica raise sea levels, but by how much is highly uncertain. Call it a “known unknown.” Until recently, scientific understanding of melting polar ice caps had been so poor that most models simply left it out.

Second, even though climate models do get a lot of things right, there are fundamental things that we don’t understand about the way the climate works.

The averages are bad enough. While 0.1°C (0.2°F) of average global surface warming per decade sounds rather manageable and perhaps even pleasant, few dispute that a century or more of warming at this pace would lead to serious costs. But these averages hide two distinct sets of uncertainties that could pose the real problems.

The first set of uncertainties is inherent in any kind of global, long-term estimate. Presenting just the global average numbers masks at least four important facts: First, temperatures in the past century have been increasing at an increasing rate. Second, despite that generally increasing trend, temperatures fluctuate across years and decades. (Hence the infamous “decade without warming.”) Third, air over the oceans is usually cooler than over land. Since two-thirds of the world is ocean, a global average increase of 0.07°C (0.13°F) per decade translated to about a 0.11°C (0.20°F) increase over land.

Finally, temperatures over the poles have warmed more than elsewhere. Arctic temperatures are expected to increase at a rate more than twice the global average. That’s particularly bad, since the poles are also where most of the world’s remaining ice is. Melting ice on land above sea level means higher seas, as the latest sea-level projections now officially acknowledge. Then there are the real, deep-seated uncertainties. To arrive at any of these projections—average or otherwise—requires taking several steps, each with its own set of known and, most vexingly, unknown unknowns.

Uncertainties exist around the amounts of global warming pollutants we emit, the link between emissions and atmospheric concentrations, the link between concentrations and temperatures, the link between temperatures and physical climate damages, the link between physical damages and their consequences, and, at least as important, how society will respond: what coping measures will be undertaken, and how effective they will prove to be.

Nailing down one of these steps—the link between concentrations and eventual temperature increases—has proven particularly elusive. The past three decades of amazing advances in climate science have gotten us no closer to pinpointing the true answer. Double the carbon dioxide concentrations in the atmosphere—something that will surely happen, unless we enact ambitious climate policies now—and eventually global average temperatures are likely to go up by between 1.5 and 4.5°C (2.7 and 8°F). Our confidence in that range has increased, but what’s now called the “likely” range hasn’t changed since the late 1970s, a fact we will revisit in chapter 3, “Fat Tails.”

The very term “fat tails” also points to another problem: 1.5 to 4.5°C (2.7 to 8°F) is “likely” in the best sense of that word. The chance is good that we will indeed find ourselves somewhere in that range for how temperatures react when concentrations double, what’s known as “climate sensitivity.” But there’s also a chance we won’t.

The Inter-governmental Panel on Climate Change (IPCC) describes anything below 1°C (1.8°F) as “extremely unlikely.” That assessment is pretty believable, given that the world has already warmed by 0.8°C (1.4°F), and we haven’t even yet doubled carbon dioxide concentrations from preindustrial levels. (The 400 ppm that the world just passed is a 40 percent increase over preindustrial levels of 280 ppm.) There’s also a chance that final temperatures from a doubling of carbon dioxide concentrations will end up above 4.5°C (8°F). It’s “unlikely,” but we can’t discount the possibility.

Meanwhile, global average warming of 4.5°C (8°F) is beyond the pale of most imagination. Recall the camels in Canada, or at least a planet that none of us would recognize. But that 4.5°C (8°F) doesn’t yet tell the full story. Climate sensitivity describes what happens when concentrations of carbon dioxide in the atmosphere double.

What if carbon dioxide concentrations more than double?

The International Energy Agency (IEA) predicts levels of 700 ppm, or two-and-a-half times preindustrial levels. Now we are looking at a “likely” range of temperatures between 2 and 6°C (3.6 and 11°F). Climate science warns that average global warming above 2°C (3.6°F) could trigger potentially devastating events.

It’s unclear what label to use for global average warming of 6°C (11°F): “catastrophic” no longer seems to do it justice. Mark Lynas, who has painstakingly detailed climate impacts degree by frightening degree, ends his book Six Degrees just there. The introduction to the final chapter on 6°C (11°F) begins with a reference to Dante’s Sixth Circle of Hell.

HELIX, a recently started project funded by the European Union, aims to determine global and regional impacts of specific levels of temperature rise. It, too, ends at 6°C (11°F). And per our own calculations in chapter 3, we are looking at an eventual chance of around 10 percent of exceeding that mark.

Whenever science points to the very real potential of these types of catastrophic outcomes, cognitive dissonance kicks in. Facts might be facts, the reasoning goes, but throwing too many of them at you at once will all but guarantee that you will dismiss them out of hand. It just feels like it can’t or shouldn’t be true.

That fickleness of human nature and the limits of our understanding are at the core of the climate policy dilemma. Smarts alone don’t seem to make much of a difference here. Solving the dilemma will take a completely different way of thinking.

THE BATHTUB PROBLEM

Think of the atmosphere as a giant bathtub. There’s a faucet—emissions from human activity—and a drain—the planet’s ability to absorb that pollution. For most of human civilization and hundreds of thousands of years before, the inflow and the outflow were in relative balance.

Then humans started burning coal and turned on the faucet far beyond what the drain could handle. The levels of carbon in the atmosphere began to rise to levels last seen in the Pliocene , over three million years ago.

What to do?

That’s the question John Sterman, an MIT professor, asked two hundred graduate students. More specifically , he asked what to do to stabilize concentrations of carbon dioxide in the atmosphere close to present levels .

How far do we need to go in turning off the faucet in order to stabilize concentrations? Here’s what not to do: stabilizing the flow of carbon into the atmosphere today won’t stabilize the carbon already there at close to present levels. You’re still adding carbon. Just because the inflow remains steady year after year, doesn’t mean the amount already in the tub doesn’t go up. Inflow and outflow need to be in balance , and that won’t happen at current levels of carbon dioxide in the tub (currently at 400 ppm) unless the inflow goes down by a lot.

That seems like an obvious point. It also seems to get lost on the average MIT graduate student, and these students aren’t exactly “average’. Still, over 80 percent of them in Sterman’s study seem to confuse the faucet with the tub. They confuse stabilizing the inflow with stabilizing the level.

from

CLIMATE SHOCK. The Economic Consequences of a Hotter Planet

by Gernot Wagner and Martin L. Weitzman.

get it at Amazon.com

***

THE SIXTH EXTINCTION

An Unnatural History.

Elizabeth Kolbert.

If there is danger in the human trajectory, it is not so much in the survival of our own species as in the fulfillment of the ultimate irony of organic evolution: that in the instant of achieving self-understanding through the mind of man, life has doomed its most beautiful creations. — E. O. Wilson

Centuries of centuries and only in the present do things happen. — Jorge Luis Borges

Prologue

Beginnings, it’s said, are apt to be shadowy. So it is with this story, which starts with the emergence of a new species maybe two hundred thousand years ago. The species does not yet have a name—nothing does—but it has the capacity to name things. As with any young species, this one’s position is precarious. Its numbers are small, and its range restricted to a slice of eastern Africa. Slowly its population grows, but quite possibly then it contracts again—some would claim nearly fatally—to just a few thousand pairs. The members of the species are not particularly swift or strong or fertile.

They are, however, singularly resourceful. Gradually they push into regions with different climates, different predators, and different prey. None of the usual constraints of habitat or geography seem to check them. They cross rivers, plateaus, mountain ranges. In coastal regions, they gather shellfish; farther inland, they hunt mammals. Everywhere they settle, they adapt and innovate. On reaching Europe, they encounter creatures very much like themselves, but stockier and probably brawnier, who have been living on the continent far longer. They interbreed with these creatures and then, by one means or another, kill them off.

The end of this affair will turn out to be exemplary. As the species expands its range, it crosses paths with animals twice, ten, and even twenty times its size: huge cats, towering bears, turtles as big as elephants, sloths that stand five metres tall. These species are more powerful and often fiercer. But they are slow to breed and are wiped out. Although a land animal, our species—ever inventive—crosses the sea. It reaches islands inhabited by evolution’s outliers: birds that lay thirty-centimetre-long eggs, pig-sized hippos, giant skinks. Accustomed to isolation, these creatures are ill-equipped to deal with the newcomers or their fellow travelers (mostly rats). Many of them, too, succumb.

The process continues, in fits and starts, for thousands of years, until the species, no longer so new, has spread to practically every corner of the globe. At this point, several things happen more or less at once that allow Homo sapiens, as it has come to call itself, to reproduce at an unprecedented rate. In a single century the population doubles; then it doubles again, and then again.

Vast forests are razed. Humans do this deliberately, in order to feed themselves. Less deliberately, they shift organisms from one continent to another, reassembling the biosphere. Meanwhile, an even stranger and more radical transformation is under way. Having discovered subterranean reserves of energy, humans begin to change the composition of the atmosphere. This, in turn, alters the climate and the chemistry of the oceans. Some plants and animals adjust by moving. They climb mountains and migrate toward the poles. But a great many—at first hundreds, then thousands, and finally perhaps millions—find themselves marooned.

Extinction rates soar, and the texture of life changes. No creature has ever altered life on the planet in this way before, and yet other, comparable events have occurred. Very, very occasionally in the distant past, the planet has undergone change so wrenching that the diversity of life has plummeted. Five of these ancient events were catastrophic enough that they’re put in their own category: the so-called Big Five. In what seems like a fantastic coincidence, but is probably no coincidence at all, the history of these events is recovered just as people come to realize that they are causing another one. When it is still too early to say whether it will reach the proportions of the Big Five, it becomes known as the Sixth Extinction.

The story of the Sixth Extinction, at least as I’ve chosen to tell it, comes in thirteen chapters. Each tracks a species that’s in some way emblematic—the American mastodon, the great auk, an ammonite that disappeared at the end of the Cretaceous alongside the dinosaurs. The creatures in the early chapters are already gone, and this part of the book is mostly concerned with the great extinctions of the past and the twisting history of their discovery, starting with the work of the French naturalist Georges Cuvier.

The second part of the book takes place very much in the present—in the increasingly fragmented Amazon rainforest, on a fast-warming slope in the Andes, on the outer reaches of the Great Barrier Reef. I chose to go to these particular places for the usual journalistic reasons—because there was a research station there or because someone invited me to tag along on an expedition. Such is the scope of the changes now taking place that I could have gone pretty much anywhere and, with the proper guidance, found signs of them.

One chapter concerns a die-off happening more or less in my own backyard (and, quite possibly, in yours). If extinction is a morbid topic, mass extinction is, well, massively so. It’s also a fascinating one. In the pages that follow, I try to convey both sides: the excitement of what’s being learned as well as the horror of it. My hope is that readers of this book will come away with an appreciation of the truly extraordinary moment in which we live.

Chapter I

The Sixth Extinction
Atelopus zeteki

The town of El Valle de Antón, in central Panama, sits in the middle of a volcanic crater formed about a million years ago. The crater is six kilometres wide, but when the weather is clear you can see the jagged hills that surround the town like the walls of a ruined tower. El Valle has one main street, a police station, and an open-air market. In addition to the usual assortment of Panama hats and vividly colored embroidery, the market offers what must be the world’s largest selection of golden-frog figurines.

There are golden frogs resting on leaves and golden frogs sitting up on their haunches and—rather more difficult to understand—golden frogs clasping cell phones. There are golden frogs wearing frilly skirts and golden frogs striking dance poses and golden frogs smoking cigarettes through a holder, after the fashion of FDR. The golden frog, which is taxicab yellow with dark brown splotches, is endemic to the area around El Valle. It is considered a lucky symbol in Panama; its image is (or at least used to be) printed on lottery tickets.

As recently as a decade ago, golden frogs were easy to spot in the hills around El Valle. The frogs are toxic—it’s been calculated that the poison contained in the skin of just one animal could kill a thousand average-sized mice—hence the vivid color, which makes them stand out against the forest floor. One creek not far from El Valle was nicknamed Thousand Frog Stream. A person walking along it would see so many golden frogs sunning themselves on the banks that, as one herpetologist who made the trip many times put it to me, “it was insane—absolutely insane.”

Then the frogs around El Valle started to disappear. The problem—it was not yet perceived as a crisis—was first noticed to the west, near Panama’s border with Costa Rica. An American graduate student happened to be studying frogs in the rainforest there. She went back to the States for a while to write her dissertation, and when she returned, she couldn’t find any frogs or, for that matter, amphibians of any kind. She had no idea what was going on, but since she needed frogs for her research, she set up a new study site, farther east.

At first the frogs at the new site seemed healthy; then the same thing happened: the amphibians vanished. The blight spread through the rainforest until, in 2002, the frogs in the hills and streams around the town of Santa Fe, about eighty kilometres west of El Valle, were effectively wiped out. In 2004, little corpses began showing up even closer to El Valle, around the town of El Copé. By this point, a group of biologists, some from Panama, others from the United States, had concluded that the golden frog was in grave danger. They decided to try to preserve a remnant population by removing a few dozen of each sex from the forest and raising them indoors.

But whatever was killing the frogs was moving even faster than the biologists had feared. Before they could act on their plan, the wave hit. I first read about the frogs of El Valle in a nature magazine for children that I picked up from my kids. The article, which was illustrated with full-color photos of the Panamanian golden frog and other brilliantly colored species, told the story of the spreading scourge and the biologists’ efforts to get out in front of it. The biologists had hoped to have a new lab facility constructed in El Valle, but it was not ready in time. They raced to save as many animals as possible, even though they had nowhere to keep them. So what did they end up doing? They put them “in a frog hotel, of course!”

The “incredible frog hotel”—really a local bed and breakfast—agreed to let the frogs stay (in their tanks) in a block of rented rooms. “With biologists at their beck and call, the frogs enjoyed first-class accommodations that included maid and room service,” the article noted. The frogs were also served delicious, fresh meals—“so fresh, in fact, the food could hop right off the plate.”

Just a few weeks after I read about the “incredible frog hotel,” I ran across another frog-related article written in a rather different key. This one, which appeared in the Proceedings of the National Academy of Sciences, was by a pair of herpetologists. It was titled “Are We in the Midst of the Sixth Mass Extinction? A View from the World of Amphibians.” The authors, David Wake, of the University of California-Berkeley, and Vance Vredenburg, of San Francisco State, noted that there “have been five great mass extinctions during the history of life on this planet.” These extinctions they described as events that led to “a profound loss of biodiversity.”

The first took place during the late Ordovician period, some 450 million years ago, when living things were still mainly confined to the water. The most devastating took place at the end of the Permian period, some 250 million years ago, and it came perilously close to emptying the earth out altogether. (This event is sometimes referred to as “the mother of mass extinctions”or “the great dying.”) The most recent—and famous—mass extinction came at the close of the Cretaceous period; it wiped out, in addition to the dinosaurs, the plesiosaurs, the mosasaurs, the ammonites, and the pterosaurs.

Wake and Vredenburg argued that, based on extinction rates among amphibians, an event of a similarly catastrophic nature was currently under way. Their article was illustrated with just one photograph, of about a dozen mountain yellow-legged frogs— all dead—lying bloated and belly-up.

I understood why a kids’ magazine had opted to publish photos of live frogs rather than dead ones. I also understood the impulse to play up the Beatrix Potter-like charms of amphibians ordering room service. Still, it seemed to me, as a journalist, that the magazine had buried the lede. Any event that has occurred just five times since the first animal with a backbone appeared, some five hundred million years ago, must qualify as exceedingly rare.

The notion that a sixth such event would be taking place right now, more or less in front of our eyes, struck me as, to use the technical term, mind-boggling. Surely this story, too—the bigger, darker, far more consequential one—deserved telling. If Wake and Vredenburg were correct, then those of us alive today not only are witnessing one of the rarest events in life’s history, we are also causing it. “One weedy species,” the pair observed, “has unwittingly achieved the ability to directly affect its own fate and that of most of the other species on this planet.” A few days after I read Wake and Vredenburg’s article, I booked a ticket to Panama.

The El Valle Amphibian Conservation Center, or EVACC (pronounced “ee-vac”), lies along a dirt road not far from the open-air market where the golden frog figurines are sold. It’s about the size of a suburban ranch house, and it occupies the back corner of a small, sleepy zoo, just beyond a cage of very sleepy sloths. The entire building is filled with tanks. There are tanks lined up against the walls and more tanks stacked at the center of the room, like books on the shelves of a library.

The taller tanks are occupied by species like the lemur tree frog, which lives in the forest canopy; the shorter tanks serve for species like the big-headed robber frog, which lives on the forest floor. Tanks of horned marsupial frogs, which carry their eggs in a pouch, sit next to tanks of casque-headed frogs, which carry their eggs on their backs. A few dozen tanks are devoted to Panamanian golden frogs, Atelopus zeteki.

Golden frogs have a distinctive, ambling gait that makes them look a bit like drunks trying to walk a straight line. They have long, skinny limbs, pointy yellow snouts, and very dark eyes, through which they seem to be regarding the world warily. At the risk of sounding weak-minded, I will say that they look intelligent. In the wild, females lay their eggs in shallow running water; males, meanwhile, defend their territory from the tops of mossy rocks.

In EVACC, each golden frog tank has its own running water, provided by its own little hose, so that the animals can breed near a simulacrum of the streams that were once their home. In one of the ersatz streams, I noticed a string of little pearl-like eggs. On a white board nearby someone had noted excitedly that one of the frogs “depositó huevos!!” EVACC sits more or less in the middle of the golden frog’s range, but it is, by design, entirely cut off from the outside world. Nothing comes into the building that has not been thoroughly disinfected, including the frogs, which, in order to gain entry, must first be treated with a solution of bleach. Human visitors are required to wear special shoes and to leave behind any bags or knapsacks or equipment that they’ve used out in the field. All of the water that enters the tanks has been filtered and specially treated.

The sealed-off nature of the place gives it the feel of a submarine or, perhaps more aptly, an ark mid-deluge.

A Panamanian golden frog, Atelopus zeteki.

EVACC’s director is a Panamanian named Edgardo Griffith. Griffith is tall and broad-shouldered, with a round face and a wide smile. He wears a silver ring in each ear and has a large tattoo of a toad’s skeleton on his left shin. Now in his mid-thirties, Griffith has devoted pretty much his entire adult life to the amphibians of El Valle, and he has turned his wife, an American who came to Panama as a Peace Corps volunteer, into a frog person, too. Griffith was the first person to notice when little carcasses started showing up in the area, and he personally collected many of the several hundred amphibians that got booked into the hotel. (The animals were transferred to EVACC once the building had been completed.)

If EVACC is a sort of ark, Griffith becomes its Noah, though one on extended duty, since already he’s been at things a good deal longer than forty days. Griffith told me that a key part of his job was getting to know the frogs as individuals. “Every one of them has the same value to me as an elephant,” he said. The first time I visited EVACC, Griffith pointed out to me the representatives of species that are now extinct in the wild. These included, in addition to the Panamanian golden frog, the Rabbs’ fringe-limbed tree frog, which was first identified only in 2005. At the time of my visit, EVACC was down to just one Rabbs’ frog, so the possibility of saving even a single, Noachian pair had obviously passed. The frog, greenish brown with yellow speckles, was about ten centimetres long, with oversized feet that gave it the look of a gawky teenager.

Rabbs’ fringe-limbed tree frogs lived in the forest above El Valle, and they laid their eggs in tree holes. In an unusual, perhaps even unique arrangement, the male frogs cared for the tadpoles by allowing their young, quite literally, to eat the skin off their backs. Griffith said that he thought there were probably many other amphibian species that had been missed in the initial collecting rush for EVACC and had since vanished; it was hard to say how many, since most of them were probably unknown to science. “Unfortunately,” he told me, “we are losing all these amphibians before we even know that they exist.” “Even the regular people in El Valle, they notice it,” he said. “They tell me, ‘What happened to the frogs? We don’t hear them calling anymore.’

When the first reports that frog populations were crashing began to circulate, a few decades ago, some of the most knowledgeable people in the field were the most skeptical. Amphibians are, after all, among the planet’s great survivors. The ancestors of today’s frogs crawled out of the water some 400 million years ago, and by 250 million years ago the earliest representatives of what would become the modern amphibian orders—one includes frogs and toads, the second newts and salamanders, and the third weird limbless creatures called caecilians—had evolved.

This means that amphibians have been around not just longer than mammals, say, or birds; they have been around since before there were dinosaurs. Most amphibians—the word comes from the Greek meaning “double life”—are still closely tied to the aquatic realm from which they emerged. (The ancient Egyptians thought that frogs were produced by the coupling of land and water during the annual flooding of the Nile.)

Their eggs, which have no shells, must be kept moist in order to develop. There are many frogs that, like the Panamanian golden frog, lay their eggs in streams. There are also frogs that lay them in temporary pools, frogs that lay them underground, and frogs that lay them in nests that they construct out of foam. In addition to frogs that carry their eggs on their backs and in pouches, there are frogs that carry them wrapped like bandages around their legs. Until recently, when both of them went extinct, there were two species of frogs, known as gastric-brooding frogs, that carried their eggs in their stomachs and gave birth to little froglets through their mouths. Amphibians emerged at a time when all the land on earth was part of a single expanse known as Pangaea. Since the breakup of Pangaea, they’ve adapted to conditions on every continent except Antarctica.

Worldwide, just over seven thousand species have been identified, and while the greatest number are found in the tropical rainforests, there are occasional amphibians, like the sandhill frog of Australia, that can live in the desert, and also amphibians, like the wood frog, that can live above the Arctic Circle. Several common North American frogs, including spring peepers, are able to survive the winter frozen solid, like popsicles.

Their extended evolutionary history means that even groups of amphibians that, from a human perspective, seem to be fairly similar may, genetically speaking, be as different from one another as, say, bats are from horses. David Wake, one of the authors of the article that sent me to Panama, was among those who initially did not believe that amphibians were disappearing. This was back in the mid-nineteen-eighties. Wake’s students began returning from frog-collecting trips in the Sierra Nevada empty-handed.

Wake remembered from his own student days, in the nineteen-sixties, that frogs in the Sierras had been difficult to avoid. “You’d be walking through meadows, and you’d inadvertently step on them,” he told me. “They were just everywhere.” Wake assumed that his students were going to the wrong spots, or that they just didn’t know how to look. Then a postdoc with several years of collecting experience told him that he couldn’t find any amphibians, either. “I said, ‘OK, I’ll go up with you, and we’ll go out to some proven places,’ “Wake recalled. “And I took him out to this proven place, and we found like two toads.”

Part of what made the situation so mystifying was the geography; frogs seemed to be vanishing not only from populated and disturbed areas but also from relatively pristine places, like the Sierras and the mountains of Central America. In the late nineteen-eighties, an American herpetologist went to the Monteverde Cloud Forest Reserve in northern Costa Rica to study the reproductive habits of golden toads.

She spent two field seasons looking; where once the toads had mated in writhing masses, a single male was sighted. (The golden toad, now classified as extinct, was actually a bright tangerine color. It was only very distantly related to the Panamanian golden frog, which, owing to a pair of glands located behind its eyes, is also technically a toad.)

Around the same time, in central Costa Rica, biologists noticed that the populations of several endemic frog species had crashed. Rare and highly specialized species were vanishing and so, too, were much more familiar ones. In Ecuador, the Jambato toad, a frequent visitor to backyard gardens, disappeared in a matter of years. And in northeastern Australia the southern day frog, once one of the most common in the region, could no longer be found.

The first clue to the mysterious killer that was claiming frogs from Queensland to California came—perhaps ironically, perhaps not—from a zoo. The National Zoo, in Washington, D.C., had been successfully raising blue poison-dart frogs, which are native to Suriname, through many generations. Then, more or less from one day to the next, the zoo’s tank-bred frogs started dropping. A veterinary pathologist at the zoo took some samples from the dead frogs and ran them through an electron scanning microscope. He found a strange microorganism on the animals’ skin, which he eventually identified as a fungus belonging to a group known as chytrids.

Chytrid fungi are nearly ubiquitous; they can be found at the tops of trees and also deep underground. This particular species, though, had never been seen before; indeed, it was so unusual that an entire genus had to be created to accommodate it. It was named Batrachochytrium dendrobatidis—batrachos is Greek for “frog”—or Bd for short.

The veterinary pathologist sent samples from infected frogs at the National Zoo to a mycologist at the University of Maine. The mycologist grew cultures of the fungus and then sent some of them back to Washington. When healthy blue poison-dart frogs were exposed to the lab-raised Bd, they sickened. Within three weeks, they were dead. Subsequent research showed that Bd interferes with frogs’ ability to take up critical electrolytes through their skin. This causes them to suffer what is, in effect, a heart attack.

The Chytrid fungus

EVACC can perhaps best be described as a work-in-progress. The week I spent at the center, a team of American volunteers was also there, helping to construct an exhibit. The exhibit was going to be open to the public, so, for biosecurity purposes, the space had to be isolated and equipped with its own separate entrance. There were holes in the walls where, eventually, glass cases were to be mounted, and around the holes someone had painted a mountain landscape very much like what you would see if you stepped outside and looked up at the hills.

The highlight of the exhibit was to be a large case full of Panamanian golden frogs, and the volunteers were trying to construct a metre-high concrete waterfall for them. But there were problems with the pumping system and difficulties getting replacement parts in a valley with no hardware store.

The volunteers seemed to be spending a lot of time hanging around, waiting. I spent a lot of time hanging around with them. Like Griffith, all of the volunteers were frog lovers. Several, I learned, were zoo-keepers who worked with amphibians back in the States. (One told me that frogs had ruined his marriage.) I was moved by the team’s dedication, which was the same sort of commitment that had gotten the frogs into the “frog hotel” and then had gotten EVACC up and running, if not entirely completed. But I couldn’t help also feeling that there was also something awfully sad about the painted green hills and the fake waterfall.

With almost no frogs left in the forests around El Valle, the case for bringing the animals into EVACC has by now clearly been proved. And yet the longer the frogs spend in the center, the tougher it is to explain what they’re doing there.

The chytrid fungus, it turns out, does not need amphibians in order to survive. This means that even after it has killed off the animals in an area, it continues to live on, doing whatever it is that chytrid fungi do. Thus, were the golden frogs at EVACC allowed to amble back into the actual hills around El Valle, they would sicken and collapse. (Though the fungus can be destroyed by bleach, it’s obviously impossible to disinfect an entire rainforest.)

Everyone I spoke to at EVACC told me that the center’s goal was to maintain the animals until they could be released to repopulate the forests, and everyone also acknowledged that they couldn’t imagine how this would actually be done. “We’ve got to hope that somehow it’s all going to come together,” Paul Crump, a herpetologist from the Houston Zoo who was directing the stalled waterfall project, told me. “We’ve got to hope that something will happen, and we’ll be able to piece it all together, and it will all be as it once was, which now that I say it out loud sounds kind of stupid.” “The point is to be able to take them back, which every day I see more like a fantasy,” Griffith said.

Once chytrid swept through El Valle, it didn’t stop; it continued to move east. It has also since arrived in Panama from the opposite direction, out of Colombia. Bd has spread through the highlands of South America and down the eastern coast of Australia, and it has crossed into New Zealand and Tasmania. It has raced through the Caribbean and has been detected in Italy, Spain, Switzerland, and France. In the U.S., it appears to have radiated from several points, not so much in a wavelike pattern as in a series of ripples. At this point, it appears to be, for all intents and purposes, unstoppable.

The same way acoustical engineers speak of “background noise” biologists talk about “background extinction.” In ordinary times—times here understood to mean whole geologic epochs—extinction takes place only very rarely, more rarely even than speciation, and it occurs at what’s known as the background extinction rate. This rate varies from one group of organisms to another; often it’s expressed in terms of extinctions per million species-years. Calculating the background extinction rate is a laborious task that entails combing through whole databases’ worth of fossils.

For what’s probably the best-studied group, which is mammals, it’s been reckoned to be roughly .25 per million species-years. This means that, since there are about fifty-five hundred mammal species wandering around today, at the background extinction rate you’d expect—once again, very roughly—one species to disappear every seven hundred years.

Mass extinctions are different. Instead of a background hum there’s a crash, and disappearance rates spike. Anthony Hallam and Paul Wignall, British paleontologists who have written extensively on the subject, define mass extinctions as events that eliminate a “significant proportion of the world’s biota in a geologically insignificant amount of time.”

Another expert, David Jablonski, characterizes mass extinctions as “substantial biodiversity losses”that occur rapidly and are “global in extent.” Michael Benton, a paleontologist who has studied the end-Permian extinction, uses the metaphor of the tree of life: “During a mass extinction, vast swathes of the tree are cut short, as if attacked by crazed, axe-wielding madmen.” A fifth paleontologist, David Raup, has tried looking at matters from the perspective of the victims: “Species are at a low risk of extinction most of the time.” But this “condition of relative safety is punctuated at rare intervals by a vastly higher risk.” The history of life thus consists of “long periods of boredom interrupted occasionally by panic.”

The Big Five extinctions, as seen in the marine fossil record, resulted in a sharp decline in diversity at the family level. If even one species from a family made it through, the family counts as a survivor, so on the species level the losses were far greater. In times of panic, whole groups of once-dominant organisms can disappear or be relegated to secondary roles, almost as if the globe has undergone a cast change.

Such wholesale losses have led paleontologists to surmise that during mass extinction events—in addition to the so-called Big Five, there have been many lesser such events—the usual rules of survival are suspended. Conditions change so drastically or so suddenly (or so drastically and so suddenly) that evolutionary history counts for little. Indeed, the very traits that have been most useful for dealing with ordinary threats may turn out, under such extraordinary circumstances, to be fatal.

A rigorous calculation of the background extinction rate for amphibians has not been performed, in part because amphibian fossils are so rare. Almost certainly, though, the rate is lower than it is for mammals. Probably, one amphibian species should go extinct every thousand years or so. That species could be from Africa or from Asia or from Australia. In other words, the odds of an individual’s witnessing such an event should be effectively zero.

Already, Griffith has observed several amphibian extinctions. Pretty much every
herpetologist working out in the field has watched several. (Even I, in the time I spent researching this book, encountered one species that has since gone extinct and three or four others, like the Panamanian golden frog, that are now extinct in the wild.) “I sought a career in herpetology because I enjoy working with animals,” Joseph Mendelson, a herpetologist at Zoo Atlanta, has written. “I did not anticipate that it would come to resemble paleontology.”

from

THE SIXTH EXTINCTION. An Unnatural History.

by Elizabeth Kolbert.

get it at Amazon.com

***

ARE WE IN THE MIDST OF THE SIXTH MASS EXTINCTION?

A view from the world of amphibians.

David B. Wake and Vance T. Vredenburg.

Many scientists argue that we are either entering or in the midst of the sixth great mass extinction. Intense human pressure, both direct and indirect, is having profound effects on natural environments.

The amphibians—frogs, salamanders, and caecilians—may be the only major group currently at risk globally. A detailed worldwide assessment and subsequent updates show that one-third or more of the 6,300 species are threatened with extinction. This trend is likely to accelerate because most amphibians occur in the tropics and have small geographic ranges that make them susceptible to extinction.

The increasing pressure from habitat destruction and climate change is likely to have major impacts on narrowly adapted and distributed species. We show that salamanders on tropical mountains are particularly at risk.

A new and significant threat to amphibians is a virulent, emerging infectious disease, chytridiomycosis, which appears to be globally distributed, and its effects may be exacerbated by global warming. This disease, which is caused by a fungal pathogen and implicated in serious declines and extinctions of >200 species of amphibians, poses the greatest threat to biodiversity of any known disease.

Our data for frogs in the Sierra Nevada of California show that the fungus is having a devastating impact on native species, already weakened by the effects of pollution and introduced predators. A general message from amphibians is that we may have little time to stave off a potential mass extinction.

*

Biodiversity is a term that refers to life on Earth in all aspects of its diversity, interactions among living organisms, and, importantly, the fates of these organisms. Scientists from many fields have raised warnings of burgeoning threats to species and habitats. Evidence of such threats (e.g., human population growth, habitat conversion, global warming and its consequences, impacts of exotic species, new pathogens, etc.) suggests that a wave of extinction is either upon us or is poised to have a profound impact.

The title of our article, suggested by the organizers, is an appropriate question at this stage of the development of biodiversity science. We examine the topic at two levels. We begin with a general overview of past mass extinctions to determine where we now stand in a relative sense. Our specific focus, however, is a taxon, the Class Amphibia. Amphibians have been studied intensively since biologists first became aware that we are witnessing a period of their severe global decline. Ironically, awareness of this phenomenon occurred at the same time the word “biodiversity” came into general use, in 1989.

FIVE MASS EXTINCTIONS

It is generally thought that there have been five great mass extinctions during the history of life on this planet (1, 2). [The first two may not qualify because new analyses show that the magnitude of the extinctions in these events was not significantly higher than in several other events (3).] In each of the five events, there was a profound loss of biodiversity during a relatively short period.

The oldest mass extinction occurred at the Ordovician–Silurian boundary (≈439 Mya). Approximately 25% of the families and nearly 60% of the genera of marine organisms were lost (1, 2). Contributing factors were great fluctuations in sea level, which resulted from extensive glaciations, followed by a period of great global warming. Terrestrial vertebrates had not yet evolved.

The next great extinction was in the Late Devonian (≈364 Mya), when 22% of marine families and 57% of marine genera, including nearly all jawless fishes, disappeared (1, 2). Global cooling after bolide impacts may have been responsible because warm water taxa were most strongly affected. Amphibians, the first terrestrial vertebrates, evolved in the Late Devonian, and they survived this extinction event (4).

The Permian–Triassic extinction (≈ 251 Mya) was by far the worst of the five mass extinctions; 95% of all species (marine as well as terrestrial) were lost, including 53% of marine families, 84% of marine genera, and 70% of land plants, insects, and vertebrates (1, 2). Causes are debated, but the leading candidate is flood volcanism emanating from the Siberian Traps, which led to profound climate change. Volcanism may have been initiated by a bolide impact, which led to loss of oxygen in the sea. The atmosphere at that time was severely hypoxic, which likely acted synergistically with other factors (5). Most terrestrial vertebrates perished, but among the few that survived were early representatives of the three orders of amphibians that survive to this day (6, 7).

The End Triassic extinction (≈199–214 Mya) was associated with the opening of the Atlantic Ocean by sea floor spreading related to massive lava floods that caused significant global warming. Marine organisms were most strongly affected (22% of marine families and 53% of marine genera were lost) (1, 2), but terrestrial organisms also experienced much extinction. Again, representatives of the three living orders of amphibians survived.

The most recent mass extinction was at the Cretaceous–Tertiary boundary (≈65 Mya); 16% of families, 47% of genera of marine organisms, and 18% of vertebrate families were lost. Most notable was the disappearance of nonavian dinosaurs. Causes continue to be debated. Leading candidates include diverse climatic changes (e.g., temperature increases in deep seas) resulting from volcanic floods in India (Deccan Traps) and consequences of a giant asteroid impact in the Gulf of Mexico (1, 2). Not only did all three orders of amphibians again escape extinction, but many, if not all, families and even a number of extant amphibian genera survived (8).

A SIXTH EXTINCTION?

The possibility that a sixth mass extinction spasm is upon us has received much attention (9). Substantial evidence suggests that an extinction event is underway.

When did the current extinction event begin? A period of climatic oscillations that began about 1 Mya, during the Pleistocene, was characterized by glaciations alternating with episodes of glacial melting (10). The oscillations led to warming and cooling that impacted many taxa. The current episode of global warming can be considered an extreme and extended interglacial period; however, most geologists treat this period as a separate epoch, the Holocene, which began ≈11,000 years ago at the end of the last glaciation. The Holocene extinctions were greater than occurred in the Pleistocene, especially with respect to large terrestrial vertebrates. As in previous extinction events, climate is thought to have played an important role, but humans may have had compounding effects. The overkill hypothesis (11) envisions these extinctions as being directly human-related. Many extinctions occurred at the end of the Pleistocene, when human impacts were first manifest in North America, in particular, and during the early Holocene. Because naive prey were largely eliminated, extinction rates decreased. Extinctions were less profound in Africa, where humans and large mammals coevolved. Most currently threatened mammals are suffering from the effects of range reduction and the introduction of exotic species (12). In contrast to the overkill hypothesis, an alternative explanation for the early mammalian extinctions is that human-mediated infectious diseases were responsible (13).

Many scientists think that we are just now entering a profound spasm of extinction and that one of its main causes is global climate change (14–16). Furthermore, both global climate change and many other factors (e.g., habitat destruction and modification) responsible for extinction events are directly related to activities of humans. In late 2007, there were 41,415 species on the International Union for Conservation of Nature Red List, of which 16,306 are threatened with extinction; 785 are already extinct (17). Among the groups most affected by the current extinction crisis are the amphibians.

AMPHIBIANS IN CRISIS

Amphibians have received much attention during the last two decades because of a now-general understanding that a larger proportion of amphibian species are at risk of extinction than those of any other taxon (18). Why this should be has perplexed amphibian specialists. A large number of factors have been implicated, including most prominently habitat destruction and epidemics of infectious disease (19); global warming also has been invoked as a contributing factor (20). What makes the amphibian case so compelling is the fact that amphibians are long-term survivors that have persisted through the last four mass extinctions.

Paradoxically, although amphibians have proven themselves to be survivors in the past, there are reasons for thinking that they might be vulnerable to current environmental challenges and, hence, serve as multipurpose sentinels of environmental health. The typical life cycle of a frog involves aquatic development of eggs and larvae and terrestrial activity as adults, thus exposing them to a wide range of environments. Frog larvae are typically herbivores, whereas adults are carnivores, thus exposing them to a wide diversity of food, predators, and parasites. Amphibians have moist skin, and cutaneous respiration is more important than respiration by lungs. The moist, well vascularized skin places them in intimate contact with their environment. One might expect them to be vulnerable to changes in water or air quality resulting from diverse pollutants. Amphibians are thermal-conformers, thus making them sensitive to environmental temperature changes, which may be especially important for tropical montane (e.g., cloud forest) species that have experienced little temperature variation. Such species may have little acclimation ability in rapidly changing thermal regimes. In general, amphibians have small geographic ranges, but this is accentuated in most terrestrial species (the majority of salamanders; a large proportion of frog species also fit this category) that develop directly from terrestrial eggs that have no free-living larval stage. These small ranges make them especially vulnerable to habitat changes that might result from either direct or indirect human activities.

Living amphibians (Class Amphibia, Subclass Lissamphibia) include frogs (Order Anura, ≈5,600 currently recognized species), salamanders (Order Caudata, ≈570 species), and caecilians (Order Gymnophiona, ≈175 species) (21). Most information concerning declines and extinctions has come from studies of frogs, which are the most numerous and by far the most widely distributed of living amphibians. Salamanders facing extinctions are centered in Middle America. Caecilians are the least well known; little information on their status with respect to extinction threats exists (18).

Amphibians are not distributed evenly around the world. Frogs and caecilians thrive in tropical regions (Fig. 1). Whereas caecilians do not occur outside the tropical zone, frogs extend northward even into the Arctic zone and southward to the southern tips of Africa and South America. Salamanders are mainly residents of the North Temperate zone, but one subclade (Bolitoglossini) of the largest family (Plethodontidae) of salamanders has radiated adaptively in the American tropics. The bolitoglossine salamanders comprise nearly 40% of living species of salamanders; ≈80% of bolitoglossines occur in Middle America, with only a few species ranging south of the equator.

Fig. 1.
Global amphibian species diversity by country visualized using density-equalizing cartograms. Country size is distorted in proportion to the total number of amphibian species occurring in each country relative to its size. (Inset) Baseline world map. Brazil (789 species) and Colombia (642) have the largest number of species. China (335) has the largest number of species in the Old World. The Democratic Republic of the Congo (215) has the largest number from continental Africa. However, 239 species are recorded from Madagascar. Australia has 225 species, and Papua New Guinea has 289. In North America, Mexico has the largest number of species (357). There are 291 species in the United States. Prepared by M. Koo.

The New World tropics have far more amphibians than anywhere else. Fig. 1 shows the number of species in relation to the size of countries (all data from ref. 21). The Global Amphibian Assessment completed its first round of evaluating the status of all then-recognized species in 2004 (18), finding 32.5% of the known species of amphibians to be “globally threatened” by using the established top three categories of threat of extinction (i.e., Vulnerable, Endangered, or Critically Endangered); 43% of species have declining populations (17). In general, greater numbers as well as proportions of species are at risk in tropical countries (e.g., Sri Lanka with 107 species, most at risk; nontropical New Zealand has an equivalent proportion, but has only 7 species) (Fig. 2). Updates from the Global Amphibian Assessment are ongoing and show that, although new species described since 2004 are mostly too poorly known to be assessed, >20% of analyzed species are in the top three categories of threat (22). Species from montane tropical regions, especially those associated with stream or streamside habitats, are most likely to be severely threatened.

Fig. 2.
Percentage of amphibian fauna in each country in the top three categories of threat (Critically Endangered, Endangered, and Threatened) (22). (Inset) Baseline world map. Visualization based on density-equalizing cartograms prepared by M. Koo.

We present a case study from our own work to explore the reasons underlying declines and extinctions of amphibians.

RANA IN THE SIERRA NEVADA OF CALIFORNIA

One of the most intensively studied examples of amphibian declines comes from the Sierra Nevada of California. The mountain range spans thousands of square kilometers of roadless habitat, most of which is designated as National Park and Forest Service Wilderness Areas, the most highly protected status allowable under U.S. law. The range contains thousands of high-elevation (1,500- to 4,200-m) alpine lakes, as well as streams and meadows, that until recently harbored large amphibian populations. Biological surveys conducted nearly a century ago by Grinnell and Storer (23) reported that amphibians were the most abundant vertebrates in the high Sierra Nevada. Because large numbers of specimens were collected from well documented localities by these early workers, the surveys provide a foundation on which current distributions can be compared. Of the seven amphibian species that occur >1,500 m in the Sierra Nevada, five (Hydromantes playcephalus, Bufo boreas, B. canorus, Rana muscosa, and R. sierrae) are threatened. The best studied are the species in the family Ranidae and include the Sierra Nevada Yellow-legged Frog (R. sierrae) and Southern Yellow-legged Frog (R. muscosa) (24). In the1980s, field biologists became aware that populations were disappearing (25), but the extent of the problem was not fully appreciated until an extensive resurvey of the Grinnell-Storer (23) sites disclosed dramatic losses (26). Especially alarming was the discovery that frogs had disappeared from 32% of the historical sites in Yosemite National Park. Furthermore, populations in most remaining sites had been reduced to a few individuals.

The yellow-legged frogs, which had been nearly ubiquitous in high-elevation sites in the early 1980s, are ideal subjects for ecological study. Their diurnal habits and their use of relatively simple and exposed alpine habitats make them readily visible and easy to capture. Typically these frogs occurred in large populations, and rarely were they found >2 m from the shores of ponds, lakes, and streams. Censuses throughout the Sierra Nevada began in the early 1990s and intensified in this century. Although most of the frog habitat in this large mountain range is protected in national parks and wilderness areas, yellow-legged frogs are now documented to have disappeared from >90% of their historic range during the last several decades (24). The most recent assessment lists them as Critically Endangered (18). Factors implicated in the declines include introduced predatory trout (27), disease (28), and air pollution (29, 30). Experiments that extirpated introduced trout led to rapid recovery of frog populations (31). Thus, for a time, there was hope that, simply by removing introduced trout, frog populations would persist and eventually spread back into formerly occupied habitat. Curiously, multiple attempts at reintroduction in the more western parts of the range clearly failed (32). Hundreds of dead frogs were encountered at both reintroduction and many other sites in the western part of the range (28), and it became apparent that predation was not the only factor affecting the frogs’ survival.

In 2001, chytridiomycosis, a disease of amphibians caused by a newly discovered pathogenic fungus [Batrachochytrium dendrobatidis (Bd)] (33) was detected in the Sierra Nevada (34). Subsequently, a retrospective study disclosed that Bd was found on eight frogs (R. muscosa, wrongly identified as R. boylii) collected on the west edge of Sequoia and Kings Canyon National Parks in 1975 (35). Infected tadpoles of these species are not killed by Bd. When tadpoles metamorphose, the juveniles became reinfected and usually die (36). However, tadpoles of yellow-legged frogs in the high Sierra Nevada live for 2 to 4 years, so even if adults and juveniles die, there is a chance that some individuals might survive if they can avoid reinfection after metamorphosis.

The disease is peculiar in many ways (37, 38). Pathogenicity is unusual for chytrid fungi, and Bd is the first chytrid known to infect vertebrates. The pathogen, found only on amphibians, apparently lives on keratin, present in tadpoles on the external mouth parts and in adults in the outer layer of the skin. The life cycle includes a sporangium in the skin, which sheds flagellated zoospores outside of the host. The zoospores then infect a new host or reinfect the original host, establishing new sporangia and completing the asexual life cycle. Sexual reproduction, seen in other chytrids, is unknown in Bd (39). Much remains to be learned about the organism (38). For example, despite its aquatic life cycle, Bd has been found on fully terrestrial species of amphibians that never enter water, and the role of zoospores in these forms is uncertain. No resting stage has been found, and no alternative hosts are known. Vectors have not been identified. It is relatively easy to rid a healthy frog of the fungus by using standard fungicides (40). Yet the fungus is surprisingly virulent. Finally, and importantly, how the fungus causes death is not clear, although it is thought to interfere with oxygen exchange and osmoregulation (41).

With associates, we have been studying frog populations in alpine watersheds within Yosemite, Sequoia, and Kings Canyon National Parks for over a decade. We recently showed that yellow-legged frogs are genetically diverse (24). Mitochondrial DNA sequence data identified six geographically distinct haplotype clades in the two species of frogs, and we recommended that these clades be used to define conservation goals. Population extinctions, based on historical records, ranged from 91.3% to 98.1% in each of the six clades, so challenges for conservation are daunting. In the last 5 years, we have documented mass die-offs (Fig. 3) and the collapse of populations due to chytridiomycosis outbreaks (28). Although the mechanism of spread is unknown, it may involve movements of adult frogs among lakes within basins or possibly movements of a common, more vagile, and terrestrial frog, Pseudacris regilla (on which Bd has been detected), ahead of the Rana infection wave. Mammals, birds, or insects also are possible vectors. We have followed movements of R. muscosa and R. sierrae using pit tags and radio tracking from 1998 to 2002 (42), and we believe that movement between local populations may be spreading the disease. The environment in this area (2,500–3,300 m) is harsh for amphibians, with isolated ponds separated by inhospitable solid granite that lacks vegetation. Small streams join many of the lakes in each basin. The maximum movement of frogs, (≈400 m) was in and near streams; most movements are <300 m. Our results are compatible with those of another study (43), which included a report of a single overland movement event. If chytridiomycosis sweeps through the Sierra Nevada the way it has through Central America (44), then population and metapopulation extinctions may be a continuing trend; we may be on the verge of losing both species.

Fig. 3.
Distribution of the critically endangered yellow-legged frogs in California. Chytridiomycosis outbreaks have had devastating effects (Rana muscosa photographed in Sixty Lake Basin, August 15, 2006).

It might be possible to arrest an epidemic. Laboratory treatments have shown that infected animals can be cleared of infection within days (40); if the dynamics of the disease can be altered or if animals can survive long enough to mount an immunological defense, then survival might be possible. Survival of infected frogs after an apparent outbreak has been seen in Australia (45), but is unknown in the Sierra Nevada frogs. The yellow-legged frogs of the Sierra Nevada are an ideal species in which to test this because they live in discreet habitat patches, are relatively easy to capture, and are highly philopatric.

COMMON THEMES IN AMPHIBIAN DECLINES

In the early 1990s, there was considerable debate about whether amphibians were in general decline or only local fluctuations in population densities were involved (46, 47). A definitive 5-year study that involved daily monitoring of a large amphibian fauna at the Monteverde Cloud Forest Preserve in Costa Rica showed that 40% (20 species of frogs) of the species had been lost (48). These instances involved some extraordinary species, such as the spectacularly colored Golden Toad (Bufo periglenes) and the Harlequin Frog (Atelopus varius). Particularly striking about this case is the highly protected status of the Preserve, so habitat destruction, the most common reason for species disappearances in general, can be excluded. The start of this decline was pinpointed to the late 1980s. At about the same time, disappearances of species from protected areas in the Australian wet tropics were recorded (49). Both species of the unique gastric brooding frogs from Australia (Rheobatrachus) disappeared. Declines in other parts of the world included most species of the generally montane, diurnal frogs of the genus Atelopus from South and lower Central America, and species of Bufo and Rana from the Sierra Nevada of California (20, 25, 44). At first all of these declines were enigmatic, but eventually two primary causal factors emerged: the infectious disease chytridiomycosis and global warming (20, 44).

Chytridiomycosis was detected almost simultaneously in Costa Rica and Australia (33). From the beginning, it was perceived as a disease with devastating consequences. It quickly swept through Costa Rica and Panama, leaving massive declines and local extinctions in its wake (44). More than half of the amphibian species in lower montane forest habitats suffered declines on the order of 80%, and several disappeared. This extinction event had been predicted on the assumption that chytridiomycosis would continue its sweep southward from Monteverde, in northwestern Costa Rica (see below), to El Cope in central Panama (44). Attention is now focused on eastern Panama and northwestern Colombia, where chythridiomycosis has yet not had evident impact.

Carcasses of animals from the Monteverde extinction event are not available, and it is not known whether Bd was responsible for frog deaths. However, Bd has been detected in many preserved specimens that were collected at different elevations along an altitudinal transect in Braulio Carrillo National Park in 1986 (50). The park is in northern Costa Rica ≈100 km southeast of Monteverde. Given the high prevalence of Bd in the specimens surveyed, it seems reasonable to assume that Bd also was present at Monteverde. Of course, there are many more species present in tropical areas (67 at El Cope, Panama) (44) than in the Sierra Nevada (seven at high elevations, but three most commonly, only two of which are aquatic), and hence there are many more opportunities for the spread of Bd among tropical species. The average moisture content of the air in the tropical environments is doubtless much higher, on average, in Central America than in the Sierra Nevada, where a characteristic dry summer rainfall pattern prevails and where there is no forest canopy because of the altitude and substrate. Although we do not know the mechanism of spread, conditions in Central America appear more suitable for the spread of an aquatic fungus.

Amphibians tend to have broader ranges in temperate regions than in the tropics. Despite many population extinctions in temperate regions, there have been few extinctions. Accordingly, the tropical species of amphibians are more at risk, but not just because of their typically small geographic ranges. Because they occur in rich, multispecies communities, the species become infected simultaneously.

Climate change has been implicated in declines since the documentation of disappearances at Monteverde (51, 52). Unusual weather conditions were initially implicated with amphibian declines. Large increases in average tropical air and sea surface temperatures were associated with El Niño events in the late 1980s; substantial warming had already occurred since the early 1970s. Temperature increases were correlated with increases in the height at which clouds formed at Monteverde and consequent reductions in the deposition of mist and cloud water critical for maintenance of cloud forest conditions during the dry season (20). Simulations using global climate models showed that greenhouse warming could have the effect of raising the cloud line by as much as 500 m at Monteverde during the dry season (20, 52).

A more general effect of climate change has been proposed for the disappearance of 100 species of tropical montane frogs of the genus Atelopus, which is widespread in southern Central and northern South America. A detailed correlational analysis revealed that ≈80 species were last seen immediately after a warm year (20). Several species disappeared from Ecuador during 1987–1988, which included the most extreme combination of dry and warm conditions in 90 years (53). Authors of this article document that the mean annual temperature in the Ecuadorian Andes has increased by ≈2°C during the last century.

Pounds and coworkers (20) hypothesized that climate change, precipitation, and increased temperature have acted synergistically in favor of the growth of the infectious chytrid fungus. They argue that global warming has shifted temperatures closer to the presumed optimal conditions for B. dendrobatidis at Monteverde and the other intermediate elevation areas of the Central and South American highlands, where most of the extinctions of Atelopus have occurred. Warming has increased cloud cover in these areas, which had the effect of elevating already higher nighttime temperatures, thus favoring fungal growth. The hypothesis has yet to be tested.

IS GLOBAL WARMING A REAL EXTINCTION THREAT?

The Intergovernmental Panel on Climate Change (IPCC) reached consensus that climate change is happening and that it is largely related to human activities (15). Estimates of global warming during the next century vary, but generally fall in the range of 2°C to 4°C, whereas rises as high as 7°C are projected for much of the United States and Europe, with even higher temperatures expected in northern Eurasia, Canada, and Alaska (15). Such rises would have devastating effects on narrowly distributed montane species, such as cloud forest and mountain-top salamanders and frogs in Middle and South America. The physiology of ectotherms such as amphibians and their ability to acclimate also are important considerations for these species (54). With climate change (already 2°C changes in temperature have been recorded in montane Ecuador) (53), altitudinal limits of plant and animal communities will shift upward and amphibians must either move with them or acclimate until adaptation occurs. Even small increases in temperature lead to significant metabolic depression in montane salamanders (55). Impacts of the different warming scenarios are all dramatic and severe (see fig. TS.6 in ref. 15). The first event predicted by the IPCC panel, “Amphibian Extinctions Increasing on Mountains,” is now an empirical fact.

In previous publications, we showed that many tropical plethodontid salamanders have very narrow altitudinal limits and are often restricted to single mountains or local mountain ranges (56). With few exceptions, species found above 1,500–2,000 m have narrow distributional limits. We have surveyed extensively a mountainous segment of eastern Mexico from the vicinity of Cerro Cofre de Perote (≈4,000 m) in central western Veracruz in the north to Cerro Pelon (≈3,000 m) in northern Oaxaca in the south. These two peaks, separated by ≈280 km, lie along the eastern crest of the Sierra Madre Oriental, a nearly continuous range that is broken only by Rio Santo Domingo (Fig. 4). Otherwise the crest lies above 1,500 m, with many peaks that rise to ≈2,000 m or higher. There are 18 species of plethodontids on both Cofre de Perote and Pelon, but only two species—widespread lowland members of Bolitoglossa—are shared. To determine the geographical limits of the other species, we have been surveying the entire crest area since the 1970s. We have learned that most of the species on each mountain are endemic to it. When we searched in the intervening region, expecting to expand the known distributional ranges for different species, we instead discovered numerous undescribed species (many since named) almost every time we explored an isolated peak at >2,000 m. On a single short trip just 5 years ago to the Sierra de Mazateca, north of the Rio Santo Domingo (Fig. 4), we discovered two new species of Pseudoeurycea and at least one new species of Thorius (57). We suspect that many species disappeared without ever having been discovered because the area is heavily populated and has experienced extensive habitat modification. Furthermore, the newly discovered species are endangered and survive in what appear to be suboptimal, disturbed habitats or in small fragments of forest. The majority of species along altitudinal transects in this area are found at >2,000 m in cloud forests that are being forced upward by global warming. On Cerro Pelon, eight of the species are found only at >2,200 m, and six of them range to the top of the mountain. Global warming threatens to force them off the mountain and into extinction.

Fig. 4.
A diagrammatic profile of the Sierra Madre Oriental from north-central Veracruz to northern Oaxaca, Mexico. The range extends in a generally north-northeast to south-southwest direction, but the section from Cofre de Perote to Loma Alta extends mainly east-northeast and has been straightened. This mountain system is home to 17 described and several unnamed species of Minute Salamanders, genus Thorius. Most of the species are clustered between 1,500 and 3,000 m. All of the species that have been evaluated are Endangered (E) or Critically Endangered (CR) and at risk of extinction, and three have been found so infrequently that they are categorized as Data Deficient (DD) (22).

The section of the Sierra Madre Oriental we have been studying is home to 17 named and 3–5 as yet unnamed species of the plethodontid salamander genus Thorius, the Minute Salamanders. All but four of these species occur exclusively at >2,000 m, often on mountains that rise only a little above that level. Of the 17 named species, 11 are listed as Endangered and 3 are listed as Critically Endangered; the remaining 4 species are so rare and poorly known that they can only be listed as Data Deficient (Fig. 4) (18). We consider this region to be a hot spot of extinction, and yet it is still very incompletely known. Based on our studies of altitudinal transects elsewhere in Middle America, we expect that the situation we have described for eastern Mexico is typical of mountainous parts of the entire region.

WHAT WILL WE LOSE?

The amphibians at greatest risk of extinction are likely to be those with relatively few populations in areas undergoing rapid habitat conversion because of human activities. Populations that are already reduced in size are especially susceptible to other stressors, such as introduced species and disease. Tropical montane species are at special risk because of global warming. These already stressed species, reduced to a few populations, also are likely to be hit hardest by Bd. However, a paradoxical fact is that new species of amphibians are being described at an unprecedented rate. In 1985, the first comprehensive account of all amphibian species reported ≈4,000 species (58). That number has now risen to >6,300, and species are being named at a rate exceeding 2% per year. Some of these species are cryptic forms that were found as a result of molecular systematic studies, but the vast majority are morphologically distinctive species mainly from tropical regions (Fig. 5). These biologically unique species often have been found as a byproduct of the heightened interest in amphibians and consequent field research. Field surveys in still relatively unstudied parts of the world (e.g., New Guinea and nearby islands, Madagascar) have resulted in many new discoveries. Among the most spectacular discoveries during this decade are a frog from India that is so distinct that it was placed in a new family (59) and a salamander from South Korea that is the only member of the Plethodontidae from Asia (60). It is impossible to know what has been overlooked or has already been lost to extinction, but there is every reason to think that the losses have been substantial.

Fig. 5.
Distribution of species of amphibians discovered and named during the period 2004–2007. Color scale bar indicates number of new species per country. (Inset) Baseline world map. Visualization is based on density-equalizing cartograms prepared by M. Koo.

The rate of extinction of amphibians is truly startling. A recent study estimates that current rates of extinction are 211 times the background extinction rate for amphibians, and rates would be as high as 25,000–45,000 times greater if all of the currently threatened species go extinct (61).

Despite these alarming estimates, amphibians are apparently doing very well in many parts of the world, and many thrive in landscapes heavily modified by human activities. Species such as the Cane Toad (Bufo marinus), the American Bullfrog (Rana catesbieana), and the Clawed Frog (Xenopus laevis) have proven to be potent invasive species, and they have not yet been shown to be afflicted by chytridiomycosis. Attempts are being made to mitigate anticipated losses of amphibian species. Promising research on bacterial skin symbionts of amphibians suggests that they may have antifungal properties (62, 63), possibly opening pathways for research on changing the outcomes of fungal attacks. Local extinctions have been so profound and widespread in Panama that a major initiative has been launched to promote in situ as well as ex situ captive breeding programs. Species will be maintained in captivity until solutions to problems such as chytridiomycosis, local habitat destruction, or others can be mitigated, at which time reintroduction programs will be developed (64). Although amphibians are suffering declines and extinctions, we predict that at least some frogs, salamanders, and caecilians will survive the current extinction event on their own or with help, even as their ancestors survived the four preceding mass extinctions.

WHAT IS THE PRINCIPAL CAUSE OF THE PRESENT EXTINCTION SPASM?

Human activities are associated directly or indirectly with nearly every aspect of the current extinction spasm. The sheer magnitude of the human population has profound implications because of the demands placed on the environment. Population growth, which has increased so dramatically since industrialization, is connected to nearly every aspect of the current extinction event. Amphibians may be taken as a case study for terrestrial organisms. They have been severely impacted by habitat modification and destruction, which frequently has been accompanied by use of fertilizers and pesticides (65). In addition, many other pollutants that have negative effects on amphibians are byproducts of human activities. Humans have been direct or indirect agents for the introduction of exotic organisms. Furthermore, with the expansion of human populations into new habitats, new infectious diseases have emerged that have real or potential consequences, not only for humans, but also for many other taxa, such as the case of Bd and amphibians (66). Perhaps the most profound impact is the human role in climate change, the effects of which may have been relatively small so far, but which will shortly be dramatic (e.g., in the sea) (16). Research building on the Global Amphibian Assessment database (18) showed that many factors are contributing to the global extinctions and declines of amphibians in addition to disease. Extrinsic forces, such as global warming and increased climatic variability, are increasing the susceptibility of high-risk species (those with small geographic ranges, low fecundity, and specialized habitats) (67). Multiple factors acting synergistically are contributing to the loss of amphibians. But we can be sure that behind all of these activities is one weedy species, Homo sapiens, which has unwittingly achieved the ability to directly affect its own fate and that of most of the other species on this planet. It is an intelligent species that potentially has the capability of exercising necessary controls on the direction, speed, and intensity of factors related to the extinction crisis. Education and changes of political direction take time that we do not have, and political leadership to date has been ineffective largely because of so many competing, short-term demands. A primary message from the amphibians, other organisms, and environments, such as the oceans, is that little time remains to stave off mass extinctions, if it is possible at all.

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PNAS.org

Is Global Warming a Public Nuisance? – Richard A. Epstein. 

New York City and a number of California municipalities, including San Francisco and Oakland, have filed law suits against five major oil companies—BP, Chevron, ConocoPhillips, Exxon Mobil, and Royal Dutch Shell—for contributing to the increased risk of global warming. These complaints cite recent scientific reports that project that sea levels will rise from 0.2 meters to 2.0 meters (or 0.66 to 6.6 feet) by 2100, with a major loss of land surface area and serious climate disruptions. They further allege that the “Defendants had full knowledge that the fossil fuels would cause catastrophic harm.” The complaints rely chiefly upon public nuisance law, which prohibits unreasonably interfering with public rights in air and water through discharges of dangerous substances—in this instance, carbon dioxide and other greenhouse gases.

These cities are demanding that each oil company named in the complaint contribute to an abatement fund to counteract the perceived future threats to the environment from global warming.

In this essay, I confine my attention to the soundness of the public nuisance theory offered by San Francisco and New York in order to explain why private lawsuits are the wrong instrument for dealing with the global warming threat.  In full disclosure, in this essay, I provide my own independent legal analysis of these complaints, which I prepared for the Manufacturer’s Accountability Project, an organization that focuses on the impact of litigation on the manufacturing industry.

The basic law of nuisance is divided into two parts, public and private, which complement each other. Private nuisances require at a minimum “an invasion of another’s interest in the private use and enjoyment of land.” The defendant must release, emit, or discharge the offensive materials—such as filth, odors, or noise—onto the plaintiff’s property. The relevant causal connection has to be so tight that there are no intervening forces between the discharge and the ensuing physical invasion of the plaintiff’s property. So, for example, the supplier of various materials and chemicals is not responsible for the waste that a manufacturer emits from their use.

The typical private nuisance dispute usually involves one party (or a very few) who either makes the discharges or suffers consequences from them. The basic intuition behind this limitation on private suits is that administrative costs balloon out of control when the number of parties who suffer some degree of harm increases, as happens when pollution is discharged into a public waterway used by hundreds of different people. Yet it is a mistake to ignore large pollution discharges simply because private law suits are an ineffective instrument to secure damages, an injunction, or both. As early as 1536, the English judges filled this gap by developing the law of public nuisances that rested, both then and now, on the key distinction between general and special damages. Thus, if the defendant erected an obstruction along a public road, none of the parties delayed by the blockage had a private right of action. But any individual who ran into the obstacle and suffered physical injuries or property damage could recover in tort. Now, the shortfall in deterrence attributable from not compensating the delayed travelers was offset by a fine against the wrongdoer, the money from which could be used to remove the obstacle or placed in the public treasury.

It is important to understand the enormous stretch in moving from traditional public nuisances to the modern global warming cases. The first point of difference is that only five companies—but no other carbon-dioxide-emitting polluter in the world—are joined as defendants. That is to say, the cities are apparently seeking to recover virtually all of their alleged abatement costs from the five named oil companies, instead of holding each only for its pro rata share of total emissions from all sources. But just what fraction of total carbon dioxide emissions can be traced to the named defendants? Note first that any release of carbon dioxide into the atmosphere has the same impact on global warming regardless of its source.

These five oil companies are responsible at most for a tiny fraction of the global total of carbon dioxide emissions. First, just looking at the American scene, some good chunk of the carbon dioxide releases are from other oil companies not named in the complaint. Another, probably larger, chunk comes from burning coal, making cement, and human and animal respiration. Carbon dioxide is also released in large quantities by forest fires, including those that recently overwhelmed Northern and Southern California. And that’s just in America; vast amounts of carbon dioxide are released from a similar range of human activities all across the globe.

Here are some numbers: As of 2015, all carbon dioxide emissions from the United States comprised 14.34 percent of the global total, while China’s emissions stood at 29.51 percent. Even if the five oil companies were somehow responsible for, say, 10 percent of the United States’ carbon dioxide emissions, that would be less than one percent of the total human releases. Under standard tort rules, the liability of each defendant must be limited to its own pro rata share of the total harm given that under Section 433A of the Restatement of Torts, there is a “reasonable basis for determining the contribution of each cause to a single harm,” in this instance measured by market shares.

Indeed, these public nuisance lawsuits are especially dubious, given that the oil companies did not by their sales emit any carbon dioxide into the atmosphere. The dangerous releases came from many different parties, both private and public, including the municipalities bringing these lawsuits. These numerous parties used these products in countless different ways, with as much knowledge of their asserted effects on global warming as these five defendants. How could the oil companies have known about the anticipated course of global warming forty years ago when key government studies done today are uncertain about the magnitude of the effects of emissions on sea levels and the economic consequences?

The first paragraph of the New York City complaint ducks these factual complexities by insisting, falsely, that crude oil was “a product causing severe harm when used exactly as intended.” But the end uses of crude oil are so varied (including, for example, the creation of various plastics in common use today) that the effective control of emissions is best done through the regulation of these end users and not the oil companies. Indeed, even for gasoline, the level of carbon dioxide emissions critically depends on the operation and maintenance of the many different types of facilities, equipment, and vehicles, all of which are beyond the direct control of the oil companies. Yet all these end users are already subject to extensive emissions controls under the Clean Air Act and countless other environmental directives, both at the state and federal level.

This sensible distribution of regulatory authority rests on the superior ability of government agencies (at least compared to the courts), often in cooperation with each other, to formulate and maintain coherent policies to regulate the emissions of carbon dioxide, as well as methane, nitrous oxide, and fluorinated gases, which the EPA calculates account for 18 percent of greenhouse gas emissions.

The issues here are especially complex for many technical and logistical reasons. One critical task is to decide the optimal level of emissions. The implicit assumption of the New York and San Francisco lawsuits is that the world would become a better place if all emissions of carbon dioxide were stopped. But that position ignores the enormous benefits that come from the use of fossil fuels, which continue to supply over 80 percent of the nation’s energy needs. No other fuel source could keep manufacturing, transportation, and commerce alive. And it is just exaggeration to claim, as the city plaintiffs do, that these oil companies “have done nearly all they could to create [the] existential threat” of global warming when in fact energy efficiency in the United States has consistently improved, particularly in generating electrical power.

No public nuisance suits for global warming can solve a problem that must be addressed by a coherent regulatory program. Instead, chaos will follow if hundreds of different states, counties, and cities are allowed to bring separate actions under state law. It bears emphasis that in 2011, a unanimous Supreme Court decision in American Electric Power Co. v. Connecticut held that the combination of the Clean Air Act and actions by the Environmental Protection Agency “against carbon-dioxide emitters . . . displace the claims that the plaintiffs seek to pursue” under a public nuisance theory brought under federal law. The Court left open the question of whether the federal regulation at the time preempted any state law cause of action for public nuisance.

But, as I argued at the time, the only viable solution was for the federal government and the EPA to “orchestrate” the effort to control emissions. The point is doubly true against these remote, upstream defendants who have not emitted anything themselves. The standard analysis of federal preemption has long held that states may not engage in their own remedial efforts, even by actions in tort, when extensive federal regulation occupies the field, or when state activity either frustrates federal action or is in conflict with it. If anything, the scope of federal oversight, actual and prospective, is far more comprehensive than it was when American Electric Power was decided. And so federal preemption alone should block a set of dubious public nuisance claims that should never have been brought in the first place.

Hoover Institute 

Climate Change in My Backyard. Santa Barbara, California – Leah C. Stokes. 

On Tuesday morning, half an inch of water fell in nearby Montecito — half an inch in five minutes. Even in the best of conditions, this pace could cause flooding. But it wasn’t the best of conditions. 

Last month, we endured the largest wildfire in California history. For two and a half weeks straight, the fire burned closer every day. Air quality turned unhealthy and forced schools to close. Businesses had to shut their doors during the peak holiday season. The local economy was decimated. I moved out of my home for weeks, as did many others. But at least I had a home to return to. Hundreds of others lost theirs. Thousands more lost their livelihoods. As a climate policy researcher, I was seeing the consequences of climate inaction in my own backyard.

Life was just beginning to get back to normal when the rains came this week, hard and fast. The scorched land could not absorb the water, and so the mudslides began.

Many residents, exhausted from weeks of displacement, were at home that night despite evacuation warnings. The forecast called for heavy rains, and the county was persistent in its preparation for mudslides and flooding. But the rain’s intensity was extreme. Rain was not supposed to fall this fast, not in our memory. No one thought it would be so bad.
Houses were ripped from their foundations. City streets were unrecognizable. Helicopters flew back and forth in a near continuous line for days, hoisting people from roofs. The names of the missing and the dead swelled.

We say the extreme rain caused this disaster. We say it was the fire. And we say that multiple years of drought didn’t help. But what caused the rain, the fire and the drought?

There is a clear climate signature in the disaster in Santa Barbara. We know that climate change is making California’s extreme rainfall events more frequent. We know it’s worsening our fires. We know that it contributed substantially to the latest drought.

There are simpler stories we could tell. Stories with more proximate causes: Those people bought in dangerous places. Those people should have left their homes. Those people are somehow to blame. These events are normal. These things just happen there.

But these simple stories mask a larger truth. How many times do we need to hear adjectives in their superlative form before we spot a pattern: largest, rainiest, driest, deadliest? Records, by their nature, are not meant to be set annually. And yet that’s what is happening. The costliest year for natural disasters in the United States was 2017. One of the longest and most severe droughts in California history concluded for most parts of the state in 2017. The five warmest years on record have all occurred since 2006, with 2017 expected to be one of the warmest yet again.

I have researched climate change policy for over a decade now. For a long time, we assumed that climate policy was stalled because it was a problem for the future. Or it would affect other people. Poorer people. Animals. Ecosystems. We assumed those parts of the world were separate from us. That we were somehow insulated. I didn’t expect to see it in my own backyard so soon.

Climate change devastated ecosystems, species and neighborhoods in Houston and much of struggling Puerto Rico last year. Now climate change has ravaged one of the wealthiest ZIP codes in the country. We know now that even the richest among us is not insulated.

These extreme events are getting worse. But when I read the news after each fresh disaster, I rarely see a mention of climate change. Whether it’s coverage of a fire in my backyard or a powerful hurricane in the Caribbean, this bigger story is usually missing. To say that it is too soon to talk about the causes of a crisis is wrongheaded. We must connect the dots.

Climate change helped cost my friends’ businesses’ revenue. Climate change helped put my community in chaos for weeks. Climate change paved the way for lost lives next door. If climate victims here and across the globe understood that carbon emissions from burning fossil fuels played a role in their losses, perhaps they would rise up to demand policy changes.

We know this could happen because research from the political scientist Regina Bateson, now a congressional candidate in California, shows that being a crime victim can spur people into activism. Perhaps some of the people affected by the fires in California, the hurricanes in Puerto Rico and Texas, and the drought in the Dakotas will be similarly motivated. Maybe some of these climate change victims will become the climate policy champions we sorely need.

It is never too soon after one of these disasters to speak truth about climate change’s role. If anything, it is too late. If we do not name the problem, we cannot hope to solve it. For my community, as much as yours, I hope we will.

*

Leah C. Stokes is an assistant professor of political science at the University of California, Santa Barbara.

New York Times 

Resistance is fertile in the battle for our climate – Kelli M. Archie. 

The futility of changing our light bulbs in order to combat climate change has become the rallying cry of those tired of policy makers placing the responsibility of action on the individual instead of the Government. And for good reason.

Upgrading to more efficient light bulbs will never make enough of a difference, not if the electricity that powers them continues to come from burning fossil fuels or, in New Zealand’s case, is 80 per cent generated from renewable sources anyway.

On the other hand, highlighting the insignificance of our individual contributions to solutions for big problems like climate change seems to give us an excuse to do nothing. After all, if the problem is so big that solving it requires international agreements and full-scale governmental buy-in, why bother inconveniencing myself or changing my habits?

Nevertheless, there is at least one thing we can all (well, most of us) do that would make a big difference in the fight against climate change – modify the way we eat.

When most people think about the causes of climate change, the images that typically pop into their heads are of smoke stacks belching black clouds of pollution and gridlocked freeways packed with gas-guzzling SUVs. Rarely do images of cows happily munching their way across a grassy hillside, or fields of monocrops being sprayed with chemicals, take centre stage. However, the relationship between food and climate change is both significant and complex.

According to the Intergovernmental Panel on Climate Change, agriculture is responsible for roughly 25 per cent of global anthropogenic greenhouse gas emissions. Most agriculture-related emissions come in the form of methane from enteric fermentation (livestock burps) and nitrous oxide from the use of natural or synthetic fertilisers. Emissions from agriculture continue to grow largely because of increasing demand for animal products (meat and dairy) and continued industrialisation of farming.

Changes in farming practices (eg implementation of sustainable farming methods) and shifting away from animal product consumption offer big opportunities for decreasing agricultural emissions and allow the individual to vote with their wallet. Recent research also suggests that as much as a quarter of all calories produced for human consumption are lost or wasted in the food supply chain – another area where individuals can make a big difference.

It’s not just about meat. Eating sustainably produced produce decreases chemical use and eating locally decreases greenhouse gas emissions required for transportation. But the problem goes even deeper.

Despite the increasing popularity of cooking shows and chefs as celebrities, people spend less time preparing their food now than at any time in history.

In some respects this is a success. The vast number of options for obtaining food without cooking it have freed us up to do things we are better at and enjoy more – like watching TV and staring at our phones. But research shows that distancing ourselves from the production of our meals leaves us even less attuned to the consequences of our choices and collectively less healthy.

Obviously I am speaking to citizens of developed nations and specifically those who have the financial freedom to change their diets. It would be outlandishly unfair to suggest those who are already struggling to maintain a healthy diet should bear the burden. But for those of us with the power to change, we shouldn’t let the magnitude of the problem lull us into complacency.

Unlike changing light bulbs, changing our eating habits has so many added benefits. Eating a plant-based diet, rich in local and sustainable products, means better health, happier animals, a cleaner environment and more local jobs.

Collectively we should be demanding rapid, top-down responses to climate change, but that doesn’t mean there isn’t room for a little old-fashioned bottom-up approach as well.

*

Dr Kelli M. Archie is a climate change lecturer in the School of Geography, Environment and Earth Sciences at Victoria University of Wellington.

New Zealand Herald 

Mass starvation is humanity’s fate if we keep flogging the land to death – George Monbiot. 

The Earth cannot accommodate our need and greed for food. We must change our diet before it’s too late.

Brexit; the crushing of democracy by billionaires; the next financial crash; a rogue US president: none of them keeps me awake at night. This is not because I don’t care – I care very much. It’s only because I have a bigger question on my mind. Where is all the food going to come from?

By the middle of this century there will be two or three billion more people on Earth. Any one of the issues I am about to list could help precipitate mass starvation. And this is before you consider how they might interact.

The trouble begins where everything begins: with soil. The UN’s famous projection that, at current rates of soil loss, the world has 60 years of harvests left appears to be supported by a new set of figures. Partly as a result of soil degradation, yields are already declining on 20% of the world’s croplands.

Now consider water loss. In places such as the North China Plain, the central United States, California and north-western India – among the world’s critical growing regions – levels of the groundwater used to irrigate crops are already reaching crisis point. Water in the Upper Ganges aquifer, for example, is being withdrawn at 50 times its recharge rate. But, to keep pace with food demand, farmers in south Asia expect to use between 80 and 200% more water by the year 2050. Where will it come from?

The next constraint is temperature. One study suggests that, all else being equal, with each degree celsius of warming the global yield of rice drops by 3%, wheat by 6% and maize by 7%. These predictions could be optimistic.

Research published in the journal Agriculture & Environmental Letters finds that 4C of warming in the US corn belt could reduce maize yields by between 84 and 100%.

The reason is that high temperatures at night disrupt the pollination process. But this describes just one component of the likely pollination crisis. Insectageddon, caused by the global deployment of scarcely tested pesticides, will account for the rest. Already, in some parts of the world, workers are now pollinating by hand. But that’s viable only for the most expensive crops.

Then there are the structural factors. Because they tend to use more labour, grow a wider range of crops and work the land more carefully, small farmers, as a rule, grow more food per hectare than large ones. In the poorer regions of the world, people with fewer than five hectares own 30% of the farmland but produce 70% of the food. Since 2000, an area of fertile ground roughly twice the size of the UK has been seized by land grabbers and consolidated into large farms, generally growing crops for export rather than the food needed by the poor.

While these multiple disasters unfold on land, the seas are being sieved of everything but plastic. Despite a massive increase in effort (bigger boats, bigger engines, more gear), the worldwide fish catch is declining by roughly 1% a year, as populations collapse. The global land grab is mirrored by a global sea grab: small fishers are displaced by big corporations, exporting fish to those who need it less but pay more. About 3 billion people depend to a large extent on fish and shellfish protein. Where will it come from?

All this would be hard enough. But as people’s incomes increase, their diet tends to shift from plant protein to animal protein. World meat production has quadrupled in 50years, but global average consumption is still only half that of the UK – where we eat roughly our bodyweight in meat every year – and just over a third of the US level. Because of the way we eat, the UK’s farmland footprint (the land required to meet our demand) is 2.4 times the size of its agricultural area. If everyone aspires to this diet, how exactly do we accommodate it?

Land required per gram of protein Square metres

The profligacy of livestock farming is astonishing. Already, 36% of the calories grown in the form of grain and pulses – and 53% of the protein – are also used to feed farm animals. Two-thirds of this food is lost in conversion from plant to animal. A graph produced last week by Our World in Data suggests that, on average, you need 0.01m2of land to produce a gram of protein from beans or peas, but 1m2 to produce it from beef cattle or sheep: a 100-fold difference.

It’s true that much of the grazing land occupied by cattle and sheep cannot be used to grow crops. But it would otherwise have sustained wildlife and ecosystems. Instead, marshes are drained, trees are felled and their seedlings grazed out, predators are exterminated, wild herbivores fenced out and other life forms gradually erased as grazing systems intensify. Astonishing places – such as the rainforests of Madagascar and Brazil – are laid waste to make room for yet more cattle.

Because there is not enough land to meet both need and greed, a global transition to eating animals means snatching food from the mouths of the poor. It also means the ecological cleansing of almost every corner of the planet.

The shift in diets would be impossible to sustain even if there were no growth in the human population. But the greater the number of people, the greater the hunger meat eating will cause. From a baseline of 2010, the UN expects meat consumption to rise by 70% by 2030 (this is three times the rate of human population growth). Partly as a result, the global demand for crops could double (from the 2005 baseline) by 2050. The land required to grow them does not exist.

When I say this keeps me up at night, I mean it. I am plagued by visions of starving people seeking to escape from grey wastes, being beaten back by armed police. I see the last rich ecosystems snuffed out, the last of the global megafauna – lions, elephants, whales and tuna – vanishing. And when I wake, I cannot assure myself that it was just a nightmare.

Other people have different dreams: the fantasy of a feeding frenzy that need never end, the fairytale of reconciling continued economic growth with a living world. If humankind spirals into societal collapse, these dreams will be the cause.

There are no easy answers, but the crucial change is a shift from an animal- to a plant-based diet. All else being equal, stopping both meat production and the use of farmland to grow biofuels could provide enough calories for another 4 billion people and double the protein available for human consumption. Artificial meat will help: one paper suggests it reduces water use by at least 82% and land use by 99%.

The next green revolution will not be like the last one. It will rely not on flogging the land to death, but on reconsidering how we use it and why. Can we do this, or do we – the richer people now consuming the living planet – find mass death easier to contemplate than changing our diet?

We’re being hurt by the fixation on economic growth at all costs – Larry Elliott. 

There had never been anything quite like the thick “pea-souper” fog that blanketed London 65 years ago. The wind dropped and the air grew damp. For five days, smoke from coal fires and power stations was trapped, making it hard to breathe. For the frail and elderly what became known as the Great Smog was deadly. Initial estimates put the death toll at 4,000.

The coal burned in the capital in 1952 turned the city into a deathtrap, but it was good for growth. It was cold and damp as well as foggy, and the more fuel that was bought, the better it was for the economy.

The same applies today. A thinktank, the New Weather Institute, estimates there will already have been 8,700 premature UK deaths this year caused by air pollution by the time of next week’s 65th anniversary. Some of them would have been avoided had more people worked from home or shared cars to the office. That would have meant fewer cars on the roads and less money spent at petrol stations. It would be good for the nation’s health but would reduce gross domestic product. As currently calculated, it would be bad for growth.

This is perverse. It is clear from the great smogs that engulfed Beijing in 2015 and New Delhi earlier this month that not all growth is good. Globally, one person dies ahead of their time every five seconds due to poor air quality. Yet the idea that success can only be measured by gross domestic product has become a fetish. When growth accelerates, it is a time for national celebration. When growth remains unchanged it is a cause for concern. When growth falls it is a time for the newsreaders to put on a long face.

Hence the response to last week’s budget, in which the Office for Budget Responsibility shaved around half a percentage point off its growth forecasts in each of the next five years. This was seen, unambiguously, as a very bad thing indeed. Commentators (me included, I hasten to add) vied with each other to find new ways of describing just how terrible it was.

Now, make no mistake, when it comes to the UK economy there is plenty to be concerned about. It is a worry that for the past decade Britain has had to work so hard just to stand still. It matters that people are taking on more debt to finance their spending habits. It is not a great idea to be investing so little and importing so much.

But it is absurd to believe that GDP provides the best – or even an accurate – picture of how well the country is really doing. Since the financial crisis, GDP has been going up, largely due to the increase in the size of the population. GDP per head is a better measure, but even then takes no account of how the growth is being divvied up. In recent decades the fruits of growth have largely been snaffled by those at the top.

GDP acts as a yardstick for things that can be measured in monetary terms, so it goes up if the defence sector exports more arms, if the City embarks on an orgy of speculation, or if betting shops double the number of fixed odds terminals. Simon Kuznets, the economist who first came up with the idea of GDP, had a point when he said it should exclude harmful things, such as military spending and advertising.

Bobby Kennedy agreed. On the campaign stump in 1968, he famously said GDP measured everything except that which made life worthwhile. “It counts special locks for our doors and the jails for the people who break them. It counts the destruction of the redwood and the loss of our natural wonder in chaotic sprawl. It counts napalm and counts nuclear warheads and armoured cars for the police to fight the riots in our cities.”

The latest GDP figure shows Britain’s economy grew by 0.4% in the third quarter of 2017. The figure includes all the things Kuznets and Kennedy abhorred, but excludes quite a lot of good things that are not counted because they are done for free.

The government could increase the size of the economy by 50% at a stroke if it included all the cleaning, cooking, childcare and other tasks around the house that are done for free. If your neighbour pays you to mow his lawn, that counts as GDP. If you mow your own lawn, it doesn’t.

At one level, the strange way in which success or failure is measured doesn’t matter all that much. As the chief economist at the Bank of England, Andy Haldane, noted in a speech earlier this week, only 10% of the public can actually define GDP. What’s more, it doesn’t seem to care too much about whether it is going up or down.

In the year or so since the EU referendum, the debate about Brexit has been framed by what the vote has meant for GDP. In the first six months, the Brexiteers thought they had the upper hand because growth averaged 0.5% a quarter. In the first half of 2017, remainers thought the pendulum had swung their way because growth slowed to 0.3%.

Both sides were assuming that people can differentiate between an economy growing by 2% a year and one growing by 1%, which they almost certainly can’t. A more relevant guide to attitudes was the recent official survey showing that the public (in England at least) got a bit happier in the year after the referendum. This probably has something to do with the continued fall in unemployment, which research has shown is more closely linked to personal wellbeing than inflation. It is, of course, possible that happiness would have been still higher had the referendum gone the other way.

But the constant use of GDP does matter because it creates a “growth at all costs” mindset. A report by the Institute for New Economic Thinking at the Oxford Martin School suggests that the upshot is the depletion of the natural world, which is not being measured or valued properly. “There is clear evidence of widespread ecosystem degradation and declining resilience in food and water systems,” it says.

In recent years there has been some recognition of the need to find a better way of measuring how things are going. There are now alternative measures of wellbeing, including national accounts that consider environmental damage. But they have not gone nearly far enough to challenge the tyranny of GDP, which is why the clincher in any argument about the economy is still that something is “bad for growth”.

As American writer Edward Abbey put it in his 1977 book The Journey Home: “Growth for the sake of growth is the ideology of the cancer cell.” He could not have been more right.

The Guardian

The next energy revolution is here – Gao Jifan.

Over the period of one decade, the capitalized cost of generating solar energy in 2015 has decreased to as low as one sixth the cost in 2005, and I believe it will not take long for solar energy generation to be economically cheaper than thermal power generation worldwide.

Every year at the World Economic Forum, energy consumption and climate change are always hot topics.

Looking back at the history of human civilisation, for a long time, firewood was the primary source of energy; however, back then, energy ultilization was low and as such air pollution emissions were also low.

The invention of the steam engine in the 18th century marked the beginning of the industrial revolution, which led to the mining and consumption of coal on a large scale. In 1920, coal accounted for 62% of primary energy consumption, indicating that the world had entered the Coal Age.

In 1965, petroleum replaced coal as the most consumed energy, which led the world into the “petroleum age”. In 1979, petroleum contributed 54% of the world energy consumption, marking the second energy revolution from coal to petroleum. Up until now, fossil fuels have continued to dominate as our energy resource.

With each new age, the use and efficiency of energy have increased significantly — as have, unfortunately, levels of severe environmental pollution. Our future energy system must therefore be clean and low-carbon to ensure the sustainable development of human civilisation.

We are now embarking on a new era of energy revolution. The energy system of the future should have the following three features:

Low carbon energy production. Fossil fuels have to be burned to release energy, which caused emissions and environmental pollution. The existing intensive industrial usage of fossil fuels has significantly harmed the environment. Meanwhile, for most economically under-developed countries around the world, the cost of clean energy is too high to be affordable.

Solar power, however, is one of the best solutions. Not only is solar energy production clean, it may also soon become a much more affordable source of energy, as technology development and innovation continues to reduce the cost of solar power generation.

……. continued at Medium.com

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Gao Jifan, President , China Photovoltaic Industry Association

The Ends of the World. Volcanic Apocalypses, Lethal Oceans and Our Quest to Understand Earth’s Past Mass Extinctions – Peter Brannen.

“As often as I have seen beds of mud, sand, and shingle, accumulated to the thickness of many thousand feet, I have felt inclined to exclaim that causes, such as the present rivers and the present beaches, could never have ground down and produced such masses. But, on the other hand, when listening to the rattling noise of these torrents, and calling to mind that whole races of animals have passed away from the face of the earth, and that during this whole period, night and day, these stones have gone rattling onwards in their course, I have thought to myself, can any mountains, any continent, withstand such waste?”

Charles Darwin

***

It is the dawn of a new geological age. A teeming swarm of Homo sapiens gathers on the banks of an estuary at the edge of the North American continent. The glaciers have retreated; the seas have risen more than 400 feet since the last ice age; and the gleaming new steel-and-glass hives of Manhattan rise up from the marshes. 

Looming over the confident city, just across the Hudson River, is the sheer cliff face of the Palisades. The gigantic columns of basalt sit in unimpressed, stony silence, as they have for 200 million years. These cliffs, covered in highway weeds and graffiti, are monuments to an ancient apocalypse. They’re made of magma that once fed burbling fountains of lava at the surface – lava that once smothered the planet from Nova Scotia to Brazil.

The eruptions flooded the atmosphere with carbon dioxide at the end of the Triassic period, roasting the planet and acidifying the oceans for thousands of years. Brief blasts of volcanic smog punctuated this super-greenhouse with cold. The runaway volcanism covered more than 4 million square miles of the planet and killed off more than three-quarters of animal life on earth in a geological instant.

I struggled to keep up with Columbia University paleontologist Paul Olsen as he bounded up the scraggly path leading from the banks of the Hudson to the base of the Palisades. In front of us, smothered under this enormous wall of now-solid magma, were the remains of a quarter-billion-year-old lake bottom, complete with exquisitely preserved fish and reptile fossils. Behind us, faintly droning, was the skyline of New York City.

I asked Olsen whether the city across the river would be preserved for future geologists to discover, like this peaceful Triassic diorama at the bottom of the rocks. He turned to consider the scenery. “You might have a layer of stuff,” he said dismissively, “but it’s not a sedimentary basin, so eventually it would erode away to nothing. You’d have bits that would make it out into the ocean and would be buried and might show up—some bottle caps, maybe. There would be some pretty heavy-duty isotopic signals. But the subway system wouldn’t fossilize or anything. It all would erode away fairly quickly.”

It is from this disorienting perspective that geologists operate: to them, millions of years run together, seas divide continents, then drain away, and great mountain ranges erode to sand in moments. It’s an outlook that’s necessary to cultivate if one wants to get a handle on the staggering depths of geological time, which recedes behind us hundreds of millions of years and stretches out before us to infinity.

If Olsen’s attitude seems dispassionate in the extreme, it’s a symptom of a lifetime’s immersion in Earth’s history, which is both vast beyond comprehension and, in some exceedingly rare moments, tragic beyond words. Animal life has been all but destroyed in sudden, planetwide exterminations five times in Earth’s history. These are the so-called Big Five mass extinctions, commonly defined as any event in which more than half of the earth’s species go extinct in fewer than a million years or so.

We now know that many of these mass extinctions seem to have happened much more quickly. Thanks to fine-scale geochronology, we know that some of the most extreme die-offs in earth history lasted only a few thousand years, at the very most, and may have been much quicker.

A more qualitative way to describe something like this is Armageddon. The most famous member of this gloomy fraternity is the End-Cretaceous mass extinction, which notably took out the (nonbird) dinosaurs 66 million years ago.

But the End-Cretaceous is only the most recent mass extinction in the history of life. The volcanic doomsday whose stony embers I saw exposed in the cliffs next to Manhattan – a disaster that brought down an alternate universe of distant crocodile relatives and global coral reef systems – struck 135 million years before the death of the dinosaurs.

This disaster and the three other major mass extinctions that preceded it are invisible, for the most part, in the public imagination, long overshadowed by the downfall of T.rex. This isn’t entirely without reason. For one thing, dinosaurs are the most charismatic characters in the fossil record, celebrities of earth history that paleontologists who work on earlier, more neglected periods scoff at as preening oversized monsters. As such, dinosaurs hog most of the popular press spared for paleontology. In addition, the dinosaurs were wiped out in spectacular fashion, with their final moments punctuated by the impact of a 6-mile-long asteroid in Mexico.

But if it was a space rock that did in the dinosaurs, it seems to have been a unique disaster. Some astronomers outside the field push the idea that periodic asteroid strikes caused each of the planet’s other four mass extinctions, but this hypothesis has virtually no support in the fossil record. In the past three decades, geologists have scoured the fossil record looking for evidence of devastating asteroid impacts at those mass extinctions, and have come up empty.

The most dependable and frequent administrators of global catastrophe, it turns out, are dramatic changes to the climate and the ocean, driven by the forces of geology itself. The three biggest mass extinctions in the past 300 million years are all associated with giant floods of lava on a continental scale – the sorts of eruptions that beggar the imagination.

Life on earth is resilient, but not infinitely so: the same volcanoes that are capable of turning whole continents inside out can also produce climatic and oceanic chaos worthy of the apocalypse. In these rare eruptive cataclysms the atmosphere becomes supercharged with volcanic carbon dioxide, and during the worst mass extinction of all time, the planet was rendered a hellish, rotting sepulcher, with hot, acidifying oceans starved of oxygen.

But in other earlier mass extinctions, it might have been neither volcanoes nor asteroids at fault. Instead, some geologists say that plate tectonics, and perhaps even biology itself, conspired to suck up CO2 and poison the oceans. While continental-scale volcanism sends CO2 soaring, in these earlier, somewhat more mysterious extinctions, carbon dioxide might have instead plummeted, imprisoning the earth in an icy crypt. Rather than spectacular collisions with other heavenly bodies, it has been these internal shocks to the earth system that have most frequently knocked the planet off course. Much of the planet’s misfortune, it seems, is homegrown. 

Luckily, these uber-catastrophes are comfortingly rare, having struck only five times in the more than half a billion years since complex life emerged (occurring, roughly, 445, 374, 252, 201, and 66 million years ago).

But it’s a history that has frightening echoes in our own world – which is undergoing changes not seen for tens of millions, or even hundreds of millions, of years. “It’s pretty clear that times of high carbon dioxide – and especially times when carbon dioxide levels rapidly rose – coincided with the mass extinctions,” writes University of Washington paleontologist and End-Permian mass extinction expert Peter Ward. “Here is the driver of extinction.” As civilization is busy demonstrating, supervolcanoes aren’t the only way to get lots of carbon buried in the rocks out into the atmosphere in a hurry.

Today humanity busies itself by digging up hundreds of millions of years of carbon buried by ancient life and ignites it all at once at the surface, in pistons and power plants – the vast, diffuse metabolism of modern civilization. If we see this task to completion and burn it all – supercharging the atmosphere with carbon like an artificial supervolcano – it will indeed get very hot, as it has before. The hottest heat waves experienced today will become the average, while future heat waves will push many parts of the world into uncharted territory, taking on a new menace that will surpass the hard limits of human physiology.

If this comes to pass, the planet will return to a condition that, though utterly alien to us, has made many appearances in the fossil record. But warm times aren’t necessarily a bad thing. The dinosaur-haunted Cretaceous was significantly richer in atmospheric CO2, and that period was consequently much warmer than today. But when climate change or ocean chemistry changes have been sudden, the result has been devastating for life. In the worst of times, the earth has been all but ruined by these climate paroxysms as lethally hot continental interiors, acidifying, anoxic oceans, and mass death swept over the planet.

This is the revelation of geology in recent years that presents the most worrying prospect for modern society. The five worst episodes in earth history have all been associated with violent changes to the planet’s carbon cycle.

Over time, this fundamental element moves back and forth between the reservoirs of biology and geology: volcanic carbon dioxide in the air is captured by carbon-based life in the sea, which dies and becomes carbonate limestone on the seafloor. When that limestone is thrust down into the earth, it’s cooked and the carbon dioxide is spit out by volcanoes into the air once more. And on and on. This is why it’s a cycle. But events like sudden, extraordinarily huge injections of carbon dioxide into the atmosphere and oceans can short-circuit this chemistry of life. This prospect is one reason why past mass extinctions have become such a vogue topic of late in the research community. Most of the scientists I spoke with over the course of reporting this book were interested in the planet’s history of near-death experiences, not just to answer an academic question, but also to learn, by studying the past, how the planet responds to exactly the sorts of shocks we’re currently inflicting on it.

This ongoing conversation in the research community is strikingly at odds with the one taking place in the broader culture. Today much of the discussion about carbon dioxide’s role in driving climate change makes it seem as though the link exists only in theory, or in computer models. But our current experiment – quickly injecting huge amounts of carbon dioxide into the atmosphere – has in fact been run many times before in the geological past, and it never ends well. 

In addition to the unanimous and terrifying projections of climate models, we also have a case history of carbon dioxide-driven climate change in the planet’s geologic past that we would be well advised to consult. These events can be instructive, even diagnostic, for our modern crises, like the patient who presents to his doctor with chest pains after a history of heart attacks. But there’s a risk of stretching the analogy too far: Earth has been many different planets over its lifetime, and though in some salient and worrying ways our modern planet and its future prospects echo some of the most frightening chapters in its history, in many other ways our modern biocrises represent a one-off, a unique disruption in the history of life.

Thankfully, we still have time. Though we’ve proven to be a destructive species, we have not produced anything even close to the levels of wanton destruction and carnage seen in previous planetary cataclysms. These are absolute worst-case scenarios.

The epitaph for humanity does not yet have to include the tragic indictment of having engineered the sixth major mass extinction in earth history.

In a world sometimes short on it, this is good news.

Like many kids, I came to the topic of mass extinctions early. As the son of a children’s librarian, I grew up in a house that was often brimming with cardboard boxes of books – the surplus of the most recent book fair. Perhaps to my mom’s frustration, I would pass over copies of Where the Red Fern Grows and The Giver and go straight for the pop-ups. Tyrannosaurs and cycads leapt from the page as I obsessed over the strange Latinate names and the even stranger creatures they described. Here an artist had decided to spangle a bizarre-looking animal called parasaurolophus in neon, while another illustrator had oviraptors draped in zebra stripes. It was irresistible: a world of sci-fi monsters that had actually existed.

But Disney’s Fantasia illuminated for me as a child an even stranger fact about this world: that it had all occurred in the past, to the music of Stravinsky’s orchestra, the dinosaurs lurched to their deaths over a cauterized landscape, and the world ended in tragedy. It was no more. Later obsessions, like the movie and book versions of Jurassic Park, only reinforced for me the melancholy of living in a world that had lost its dragons.

In the past few decades, geologists have started filling in the rough sketches of the Big Five mass extinctions with gruesome detail, but the story has largely eluded the public imagination. Our conception of history tends to stretch back only a few thousand years at most, and typically only a few hundred. This is a scandalously shortsighted appreciation of what came before – like reading only the last sentence of a book and claiming to understand what’s in the rest of the library. 

That the planet has nearly died five times over the past 500 million years is a remarkable fact, and as we, as a civilization, push the chemistry and temperature of the climate-ocean system into territory not seen for tens of millions of years, we should be curious about where the hard limits are. Just how bad could it get?

The history of mass extinctions provides the answer to this question. Visiting Earth’s turbulent and unfamiliar past provides a possible window into our future. Forgotten worlds spill from the sides of highways, from beach cliffs, and from the edges of baseball fields, hiding in plain sight. This was perhaps the central revelation to me as I began to accompany paleontologists in the field to learn more about the five major mass extinctions. I didn’t have to talk my way onto expeditions to the Arctic or the Gobi Desert to find the strange stratigraphy of long-past worlds. We live on a palimpsest of earth history. 

The lesson of geology is that we inherit this world – this “antique planet with a brand new civilization,” as Carl Sagan put it – from countless vanished ages. To see the world through the lens of geology is to see the world for the first time.

In North America, fossils are found not only in the mythic Southwest and in exposed Arctic mountainsides but hidden under Walmart parking lots, in quarries, and in road cuts on the interstate. Underneath Cincinnati is an endless fossil bas-relief of tropical sea life in the early oceans of the Ordovician period, which ended half a billion years ago in the second worst extinction in Earth’s history. 

There are plesiosaurs in riverbanks in downtown Austin, saber-toothed cats in Los Angeles, and killer crocs from the Triassic under Dulles Airport outside of Washington, DC. In Cleveland’s riverbanks are the armor-plated remains of a guillotine-mouthed, titanic fish from the Devonian period, 360 million years old. The wreckage from the Big Five mass extinctions lies on remote, verdant islands in the Canadian Maritimes, on icier patches in Antarctica and Greenland, under Mayan temples in Mexico, strewn across the desolation of South Africa’s Karoo Desert, and on the edges of farmland in China.

But this legacy of disaster is also visible next to skyscrapers in New York City and in the shales of the Midwest (so profitable for frackers and environmental fundraisers alike) that were forged in the chaos of the Late Devonian mass extinctions. Rising out of the deserts of West Texas are the Guadalupe Mountains, a haunted monument built almost entirely from ancient sea animals in the full bloom of life before the single worst chapter in the planet’s history: a period of crises capped by a carbon dioxide–driven global warming catastrophe that killed off 90 percent of life on Earth.

Life on earth constitutes a remarkably thin glaze of interesting chemistry on an otherwise unremarkable, cooling ball of stone, hovering like a sand grain in an endless ocean of empty space. This sheet of life that coats the planet – a feature of our world that has been almost miraculously durable over Earth’s history – is perhaps unique in the galaxy. But viewed through the lens of mass extinctions, it’s also remarkably fragile: when crises push the planet outside a narrow set of surface conditions, it has been nearly sterilized.

Much has been made of the search beyond our planet for spectacular external threats like asteroids, but we should be equally vigilant about the subtler threats from within. As the roster of lifeless planets in our solar system attests, the agreeable chemistry and conditions on the surface of the earth are incredibly unusual. And as the history of mass extinctions demonstrates, they’re not a given. 

In researching these ancient disasters, I expected to find a story as neat and tidy as the one about the asteroid that killed the dinosaurs. What I found instead was a frontier of discovery with much left to be unearthed, and a story still largely obscured by the fog of deep time. In my travels I became acquainted with whole worlds, still called “Earth”, that I had scarcely known existed, brought low by a suite of world-ending forces far subtler, but just as ominous, as asteroids.

This book is a woefully incomplete testament to the ingenuity of those who have labored to piece this fractured, and still unfinished – puzzle together, as well as a survey of the unfamiliar geography of deep time that surrounds us. It’s also an exploration of the turbulent centuries to come and the long-term prospects for life on this strangely hospitable but vulnerable planet that hurtles through a perilous universe. 

After hiking the Palisades, Olsen and I hit up one of the dozens of Vietnamese pho restaurants in the nearby Fort Lee neighborhood, where a snarl of highways branch out of the George Washington Bridge. Contemplating the history of the region and the ancient hellscape created by the rocks underneath us, I found it difficult not to wonder about the future. Currently the carbon dioxide concentration in the atmosphere hovers at around 400 parts per million (ppm) – probably the highest it’s been since the middle of the Pliocene epoch 3 million years ago. 

What will life be like on the planet at 1,000 parts per million, which some climate scientists and policymakers project for the coming decades if we continue to take a business-as-usual approach to emissions? “The last time anything like that occurred, we had no polar ice at all and sea levels were hundreds of feet higher,” Olsen said, noting that crocodiles and lemur-relatives inhabited the tropical northern shores of Canada. “Ocean temperatures in the tropics were possibly 40 degrees Celsius on average, which would be completely alien to us now. “The interior of continents,” he continued, “endured persistently lethal conditions.” 

I put the question a little more bluntly, asking him whether we might be at the beginning of another mass extinction. “Yeah,” he said, resting his chopsticks for a moment. “Yeah. Although the one that would be obvious in the fossil record happened over a 50,000-year interval from the time that humans spread out of Africa and wiped out all the megafauna. That’s the one that will show up like gangbusters in the fossil record. Someday they might say that the industrial spread of humans was just the coup de grâce.” 

***

The Ends of the World. Volcanic Apocalypses, Lethal Oceans and Our Quest to Understand Earth’s Past Mass Extinctions. 

by Peter Brannen.

get it at Amazon.com

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Is It Time To Take Away The Carbon Punch Bowl? – Josh Ryan-Collins. 

Climate change poses serious financial risks. Perhaps the biggest systemic risk is a disorderly transition to a low carbon economy. As noted in the Bank of England’s, current forecasts suggest that to keep global average temperatures below 2 degrees, around two-thirds of current fossil reserves must be left in the ground. Companies with carbon-intensive business models are facing large potential losses since their activities and current market value rest upon the future extraction of what is, in effect, ‘unburnable’ carbon. 

Banks and other financial institutions which make loans to these companies may face higher than expected default rates and non-performing loans because a large part of these companies’ future income – needed to repay loans – is dependent on the use of these ‘stranded assets’.

Although only a small percentage of banks’ loans go directly to carbon-intensive industries (such as energy companies), transition risk might also affect a range of other industries such as transport, construction as well as households, to which banks are much more exposed.

For example, environmental taxes and regulations imposed on diesel cars could have a disastrous impact on car finance companies whose leasing models are dependent on the ability to sell on second hand cars at a reasonable value.

Eco Stress Tests

A recent attempt to conduct a climate change stress test on Eurozone banks found their exposures to this wider range of sectors to be similar in size to their existing capital base.

Yet the main approach of central banks and financial regulators, ministries of finance and international bodies such as the Financial Stability Board to the problem of stranded assets has been to rely upon market-based solutions.

In particular, there have been major initiatives to encourage the voluntary disclosure of fossil fuel assets and exposures by both companies and financial institutions. The hope is that with better information, financial institutions will naturally adjust their investment and lending behavior away from carbon intensive activities, leading to a gradual fall in value of such assets.

Whilst better market information is to be welcomed, the financial crisis of 2007-08 made clear the danger of relying on the market and financial institutions’ ability to judge and price risk themselves.

This prompted central banks to take a new approach: ‘macroprudential policy’. This recognizes that market actors may be blind to certain forms of economy-wide systemic risk – including for example the build-up of mortgage debt and house prices relative to incomes. Regulators have a duty to step in when markets are becoming overheated and risk is not properly priced into asset prices.

In more colourful terms, central banks have a duty to ‘take away the punch bowl as the party was getting out of control’. 

Credit rating agencies, equity and bond analysts typically focus on the relatively short term, e.g. 1-5 years, and assume linear returns on investment. But climate change, as Mark Carney has noted, poses a longer term, systemic risk with potentially non-linear impacts involving very rapid price adjustments to carbon-assets.

Green Macroprudence

What then might ‘green’ macroprudential policy look like? Most obviously, it might require banks to hold more capital against carbon-intensive (‘brown’) loans given the increased forward-looking risk of default.

The EU high level expert group on sustainable finance backed this idea in its recent interim report, arguing that a ‘brown-penalising’ factor would ‘yield a constellation in which risk and policy considerations go in the same direction’. 

Other options could involve quantitative caps on debt-financing of firms heavily dependent on carbon assets in line with a below 2 degrees temperature scenario; or some form of counter-cyclical measure, whereby capital requirements would be raised if lending to carbon-intensive sectors began to increase. All these tools are currently in use by a number of central banks to guard against excessive real estate exposures.

The most common argument against interventions of this type is that it is the job of the government, not the independent central bank, to impose policies to repress or support particular sectors of the economy.

Again, however, this seems inconsistent with macroprudential policy. In the aftermath of the financial crisis, independent central banks took on responsibility for interventions in the mortgage market precisely because it was felt politicians, ministries of finance and the market itself would find it harder to ‘Take away the Punchbowl’ given political pressures. For example, in countries where the majority of voters are home-owners or would like to become so, policies that restrict mortgage credit or reduce house price growth are likely to be highly unpopular.

Before The Deluge

The same issues apply to the problem of stranded assets. Politicians and ministers of finance are under enormous pressure not to regulate against large companies locked into unsustainable industries. The lobbying power of these organisations is evident in the still enormous subsidies they receive – far outweighing the subsidies flowing into renewable energy.

There is, as with house prices, also pressure from voters. The introduction of a carbon tax for example would almost certainly push up the cost of the majority of household’s energy bills.

This is not to say that governments should not also be going much further much faster to address the risks from climate change. It is rather to say that central banks have a duty to take financial stability risk seriously, whatever sector of the economy it is coming from.

No doubt designing effective green macroprudential policy will be challenging and have some unintended side effects. But many pension companies and other long-term institutional investors are already developing sophisticated green investment strategies upon which central banks and regulators could build.

Ultimately, it is surely better to have imperfect regulatory frameworks that begin to steer finance in the right direction and deflate the carbon bubble than clean up what could be a very big financial mess after the event.

***

About Josh Ryan-Collins

Josh Ryan-Collins is a Senior Economist at the New Economics Foundation where he leads work on macroeconomics and finance. He is the lead author of two books: Where Does Money Come From? and Rethinking the Economics of Land and Housing. He has broadcast experience on the BBC, Sky News and Radio 4 and his work has featured in the Guardian and Wall Street Journal.

Social Europe

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What Exxon Mobil Didn’t Say About Climate Change – Geoffrey Supran and Naomi Oreskes. 

Scrutiny is mounting on the world’s largest publicly traded oil and gas company. On multiple legal fronts the question is being asked: Did Exxon Mobil’s communications about climate change break the law?

That’s what some of Exxon Mobil’s current and former employees think. In February, they filed a lawsuit arguing that the company deceived them by making false and misleading statements about the financial risks of climate change, which they argue affected the value of shares they bought as part of a company-sponsored savings plan. Other Exxon Mobil shareholders are bringing similar charges against the company in a separate class-action securities fraud case.

And just last month, three California communities sued 37 oil, coal and gas companies, including Exxon Mobil, for contributing to sea level rise while engaging in a “coordinated, multifront effort to conceal and deny their own knowledge of those threats.” At the same time, the New York and Massachusetts attorneys general continue to investigate whether Exxon Mobil may have violated racketeering, consumer protection or investor protection statutes. And the federal Securities and Exchange Commission started a probe of its own last fall, asking the company about its longstanding policy of not writing down the value of its oil reserves, as other companies had done.

The question dominating these cases is whether the company misled consumers, shareholders or the public about the environmental or business risks of climate change, or about the risk that oil and gas reserves might become stranded assets that won’t be developed, affecting shareholder value.

Part of the impetus for these suspicions was reporting by Inside Climate News and The Los Angeles Times in 2015 that concluded Exxon Mobil had long known about the risks of climate change but denied them in public. The company responded that the allegations were false and “deliberately cherry-picked,” and that anyone who looked into the matter would see that.

“Read the documents,” the company said, “and make up your own mind.”

A year ago we took up this challenge. We have read all of the documents, analyzed them according to established social science methods, and made up our minds. Today, we are publishing the results of our peer reviewed analysis in the journal Environmental Research Letters. To our knowledge, this is the first academic, empirical analysis of Exxon Mobil’s 40-year history of climate change communications. (Our research was funded by Harvard University Faculty Development Funds and by the Rockefeller Family Fund, which also helped finance the reporting by Inside Climate News and the Columbia University Graduate School of Journalism, which published its examination of Exxon Mobil with The Los Angeles Times.)

Our findings are clear: Exxon Mobil misled the public about the state of climate science and its implications. Available documents show a systematic, quantifiable discrepancy between what Exxon Mobil’s scientists and executives discussed about climate change in private and in academic circles, and what it presented to the general public.

We applied an empirical method known as content analysis to all relevant, publicly available internal company files that have led to allegations against Exxon Mobil, as well as all peer-reviewed and non-peer-reviewed publications offered by the company in response. We also analyzed 36 of the company’s paid “advertorials” about climate change that appeared as editorial-style advertisements on the Op-Ed pages of The New York Times between 1989 and 2004.

In total, we analyzed 187 documents generated between 1977 and 2014. We coded each document to characterize its positions on climate change as real, human-caused, serious and solvable. (Research has shown that these four factors are key predictors of public support for climate policies. Not coincidentally, they also underpin most narratives of climate skepticism and denial.) We found that, from as early as the 1970s, Exxon Mobil (and its predecessors Exxon and Mobil) not only knew about emerging climate science, but also contributed research to it. Scientific reports and articles written or cowritten by Exxon Mobil employees acknowledged that global warming was a real and serious threat. They also noted it could be addressed by reducing fossil fuel use, meaning that fossil fuel reserves might one day become stranded assets.

For the most part their research was highly technical, hidden behind the walls of Exxon Mobil offices, or reported in academic publications with access only through a paywall.

In contrast, the company’s advertorials in The New York Times discussing climate change were designed to reach and influence the public, and the potential readership was in the millions. Each advertorial cost roughly $31,000. They overwhelmingly emphasized scientific uncertainties about climate change and promoted a narrative that was largely inconsistent with the views of most climate scientists, including Exxon Mobil’s own.

In 1997, for instance, in an ad titled “Reset the Alarm,” the company argued: “Let’s face it: The science of climate change is too uncertain to mandate a plan of action that could plunge economies into turmoil.” The company added, “We still don’t know what role man-made greenhouse gases might play in warming the planet.”

Some advertorials conflicted with Exxon Mobil research published the very same year.

In some cases, they included explicit factual misrepresentation, for instance, directly contradicting the Intergovernmental Panel on Climate Change and presenting data in a very misleading way, according to the independent researcher who produced that data, Lloyd Keigwin, a senior scientist in geology and geophysics at the Woods Hole Oceanographic Institution.

In short, Exxon Mobil contributed quietly to climate science and loudly to raising doubts about it. We found that, accounting for reasonable doubt given the state of the science at the time of each document, roughly 80 percent of the company’s academic and internal papers acknowledged that climate change is real and human-caused. But 81 percent of their climate change advertorials in one way or another expressed doubt.

Of course, any analysis of words is subject to interpretation. It’s for this reason that we used established social science methods and subjected our analysis to peer review, to verify that our claims are supported by evidence, were analyzed according to tested methods and are not just a matter of our opinion.

Exxon Mobil will no doubt challenge our peer-reviewed study, just as it has challenged three decades of peer-reviewed climate science. (In a comment, Exxon Mobil disagreed with our conclusion and said that its statements on public policy and climate science “have always reflected the global understanding of the issue.”) But while we can debate the details, the overall picture is clear: Even while Exxon Mobil scientists were contributing to climate science and writing reports that explained it to their bosses, the company was paying for advertisements that told a very different tale.

***

Geoffrey Supran is a postdoctoral fellow and Naomi Oreskes is a professor of the history of science, both at Harvard.

New York Times 

When Will Climate Change Make the Earth Too Hot For Humans? Heat Death – David Wallace Wells. 

The bahraining of New York.

Humans, like all mammals, are heat engines; surviving means having to continually cool off, like panting dogs. For that, the temperature needs to be low enough for the air to act as a kind of refrigerant, drawing heat off the skin so the engine can keep pumping. At seven degrees of warming, that would become impossible for large portions of the planet’s equatorial band, and especially the tropics, where humidity adds to the problem; in the jungles of Costa Rica, for instance, where humidity routinely tops 90 percent, simply moving around outside when it’s over 105 degrees Fahrenheit would be lethal. And the effect would be fast: Within a few hours, a human body would be cooked to death from both inside and out.

Climate-change skeptics point out that the planet has warmed and cooled many times before, but the climate window that has allowed for human life is very narrow, even by the standards of planetary history. At 11 or 12 degrees of warming, more than half the world’s population, as distributed today, would die of direct heat. Things almost certainly won’t get that hot this century, though models of unabated emissions do bring us that far eventually. This century, and especially in the tropics, the pain points will pinch much more quickly even than an increase of seven degrees. The key factor is something called wet-bulb temperature, which is a term of measurement as home-laboratory-kit as it sounds: the heat registered on a thermometer wrapped in a damp sock as it’s swung around in the air (since the moisture evaporates from a sock more quickly in dry air, this single number reflects both heat and humidity). At present, most regions reach a wet-bulb maximum of 26 or 27 degrees Celsius; the true red line for habitability is 35 degrees. What is called heat stress comes much sooner.

Actually, we’re about there already. Since 1980, the planet has experienced a 50-fold increase in the number of places experiencing dangerous or extreme heat; a bigger increase is to come. The five warmest summers in Europe since 1500 have all occurred since 2002, and soon, the IPCC warns, simply being outdoors that time of year will be unhealthy for much of the globe. Even if we meet the Paris goals of two degrees warming, cities like Karachi and Kolkata will become close to uninhabitable, annually encountering deadly heat waves like those that crippled them in 2015. At four degrees, the deadly European heat wave of 2003, which killed as many as 2,000 people a day, will be a normal summer. At six, according to an assessment focused only on effects within the U.S. from the National Oceanic and Atmospheric Administration, summer labor of any kind would become impossible in the lower Mississippi Valley, and everybody in the country east of the Rockies would be under more heat stress than anyone, anywhere, in the world today.

As Joseph Romm has put it in his authoritative primer Climate Change : What Everyone Needs to Know, heat stress in New York City would exceed that of present-day Bahrain, one of the planet’s hottest spots, and the temperature in Bahrain “would induce hyperthermia in even sleeping humans.” The high-end IPCC estimate, remember, is two degrees warmer still. By the end of the century, the World Bank has estimated, the coolest months in tropical South America, Africa, and the Pacific are likely to be warmer than the warmest months at the end of the 20th century. Air-conditioning can help but will ultimately only add to the carbon problem; plus, the climate-controlled malls of the Arab emirates aside, it is not remotely plausible to wholesale air-condition all the hottest parts of the world, many of them also the poorest. And indeed, the crisis will be most dramatic across the Middle East and Persian Gulf, where in 2015 the heat index registered temperatures as high as 163 degrees Fahrenheit. As soon as several decades from now, the hajj will become physically impossible for the 2 million Muslims who make the pilgrimage each year.

It is not just the hajj, and it is not just Mecca; heat is already killing us. In the sugarcane region of El Salvador, as much as one-fifth of the population has chronic kidney disease, including over a quarter of the men, the presumed result of dehydration from working the fields they were able to comfortably harvest as recently as two decades ago. With dialysis, which is expensive, those with kidney failure can expect to live five years; without it, life expectancy is in the weeks. Of course, heat stress promises to pummel us in places other than our kidneys, too. As I type that sentence, in the California desert in mid-June, it is 121 degrees outside my door. It is not a record high.

III. The End of Food

Praying for cornfields in the tundra.

continue reading: New York Magazine

When Will Climate Change Make the Earth Too Hot For Humans? Doomsday – David Wallace Wells. 

I. ‘Doomsday’

Peering beyond scientific reticence.

It is, I promise, worse than you think. If your anxiety about global warming is dominated by fears of sea-level rise, you are barely scratching the surface of what terrors are possible, even within the lifetime of a teenager today. And yet the swelling seas — and the cities they will drown — have so dominated the picture of global warming, and so overwhelmed our capacity for climate panic, that they have occluded our perception of other threats, many much closer at hand. Rising oceans are bad, in fact very bad; but fleeing the coastline will not be enough.

Indeed, absent a significant adjustment to how billions of humans conduct their lives, parts of the Earth will likely become close to uninhabitable, and other parts horrifically inhospitable, as soon as the end of this century.

Even when we train our eyes on climate change, we are unable to comprehend its scope. This past winter, a string of days 60 and 70 degrees warmer than normal baked the North Pole, melting the permafrost that encased Norway’s Svalbard seed vault — a global food bank nicknamed “Doomsday,” designed to ensure that our agriculture survives any catastrophe, and which appeared to have been flooded by climate change less than ten years after being built.

The Doomsday vault is fine, for now: The structure has been secured and the seeds are safe. But treating the episode as a parable of impending flooding missed the more important news. Until recently, permafrost was not a major concern of climate scientists, because, as the name suggests, it was soil that stayed permanently frozen. But Arctic permafrost contains 1.8 trillion tons of carbon, more than twice as much as is currently suspended in the Earth’s atmosphere. When it thaws and is released, that carbon may evaporate as methane, which is 34 times as powerful a greenhouse-gas warming blanket as carbon dioxide when judged on the timescale of a century; when judged on the timescale of two decades, it is 86 times as powerful. In other words, we have, trapped in Arctic permafrost, twice as much carbon as is currently wrecking the atmosphere of the planet, all of it scheduled to be released at a date that keeps getting moved up, partially in the form of a gas that multiplies its warming power 86 times over.

Maybe you know that already — there are alarming stories in the news every day, like those, last month, that seemed to suggest satellite data showed the globe warming since 1998 more than twice as fast as scientists had thought (in fact, the underlying story was considerably less alarming than the headlines). Or the news from Antarctica this past May, when a crack in an ice shelf grew 11 miles in six days, then kept going; the break now has just three miles to go — by the time you read this, it may already have met the open water, where it will drop into the sea one of the biggest icebergs ever, a process known poetically as “calving.”

But no matter how well-informed you are, you are surely not alarmed enough. Over the past decades, our culture has gone apocalyptic with zombie movies and Mad Max dystopias, perhaps the collective result of displaced climate anxiety, and yet when it comes to contemplating real-world warming dangers, we suffer from an incredible failure of imagination. The reasons for that are many: the timid language of scientific probabilities, which the climatologist James Hansen once called “scientific reticence” in a paper chastising scientists for editing their own observations so conscientiously that they failed to communicate how dire the threat really was; the fact that the country is dominated by a group of technocrats who believe any problem can be solved and an opposing culture that doesn’t even see warming as a problem worth addressing; the way that climate denialism has made scientists even more cautious in offering speculative warnings; the simple speed of change and, also, its slowness, such that we are only seeing effects now of warming from decades past; our uncertainty about uncertainty, which the climate writer Naomi Oreskes in particular has suggested stops us from preparing as though anything worse than a median outcome were even possible; the way we assume climate change will hit hardest elsewhere, not everywhere; the smallness (two degrees) and largeness (1.8 trillion tons) and abstractness (400 parts per million) of the numbers; the discomfort of considering a problem that is very difficult, if not impossible, to solve; the altogether incomprehensible scale of that problem, which amounts to the prospect of our own annihilation; simple fear. But aversion arising from fear is a form of denial, too.

In between scientific reticence and science fiction is science itself. This article is the result of dozens of interviews and exchanges with climatologists and researchers in related fields and reflects hundreds of scientific papers on the subject of climate change. What follows is not a series of predictions of what will happen — that will be determined in large part by the much-less-certain science of human response. Instead, it is a portrait of our best understanding of where the planet is heading absent aggressive action. It is unlikely that all of these warming scenarios will be fully realized, largely because the devastation along the way will shake our complacency. But those scenarios, and not the present climate, are the baseline. In fact, they are our schedule.

The present tense of climate change — the destruction we’ve already baked into our future — is horrifying enough. Most people talk as if Miami and Bangladesh still have a chance of surviving; most of the scientists I spoke with assume we’ll lose them within the century, even if we stop burning fossil fuel in the next decade. Two degrees of warming used to be considered the threshold of catastrophe: tens of millions of climate refugees unleashed upon an unprepared world. Now two degrees is our goal, per the Paris climate accords, and experts give us only slim odds of hitting it. The U.N. Intergovernmental Panel on Climate Change issues serial reports, often called the “gold standard” of climate research; the most recent one projects us to hit four degrees of warming by the beginning of the next century, should we stay the present course. But that’s just a median projection. The upper end of the probability curve runs as high as eight degrees — and the authors still haven’t figured out how to deal with that permafrost melt. The IPCC reports also don’t fully account for the albedo effect (less ice means less reflected and more absorbed sunlight, hence more warming); more cloud cover (which traps heat); or the dieback of forests and other flora (which extract carbon from the atmosphere). Each of these promises to accelerate warming, and the history of the planet shows that temperature can shift as much as five degrees Celsius within thirteen years. The last time the planet was even four degrees warmer, Peter Brannen points out in The Ends of the World, his new history of the planet’s major extinction events, the oceans were hundreds of feet higher.*

The Earth has experienced five mass extinctions before the one we are living through now, each so complete a slate-wiping of the evolutionary record it functioned as a resetting of the planetary clock, and many climate scientists will tell you they are the best analog for the ecological future we are diving headlong into. Unless you are a teenager, you probably read in your high-school textbooks that these extinctions were the result of asteroids. In fact, all but the one that killed the dinosaurs were caused by climate change produced by greenhouse gas. The most notorious was 252 million years ago; it began when carbon warmed the planet by five degrees, accelerated when that warming triggered the release of methane in the Arctic, and ended with 97 percent of all life on Earth dead. We are currently adding carbon to the atmosphere at a considerably faster rate; by most estimates, at least ten times faster. The rate is accelerating. This is what Stephen Hawking had in mind when he said, this spring, that the species needs to colonize other planets in the next century to survive, and what drove Elon Musk, last month, to unveil his plans to build a Mars habitat in 40 to 100 years. These are nonspecialists, of course, and probably as inclined to irrational panic as you or I. But the many sober-minded scientists I interviewed over the past several months — the most credentialed and tenured in the field, few of them inclined to alarmism and many advisers to the IPCC who nevertheless criticize its conservatism — have quietly reached an apocalyptic conclusion, too: No plausible program of emissions reductions alone can prevent climate disaster.

Over the past few decades, the term “Anthropocene” has climbed out of academic discourse and into the popular imagination, a name given to the geologic era we live in now, and a way to signal that it is a new era, defined on the wall chart of deep history by human intervention. One problem with the term is that it implies a conquest of nature (and even echoes the biblical “dominion”). And however sanguine you might be about the proposition that we have already ravaged the natural world, which we surely have, it is another thing entirely to consider the possibility that we have only provoked it, engineering first in ignorance and then in denial a climate system that will now go to war with us for many centuries, perhaps until it destroys us. That is what Wallace Smith Broecker, the avuncular oceanographer who coined the term “global warming,” means when he calls the planet an “angry beast.” You could also go with “war machine.” Each day we arm it more.

II. Heat Death

The bahraining of New York.

continue reading: New York Magazine

G20: Does Donald Trump’s awkward performance indicate America’s decline as a world power? – Chris Uhlmann. 

The G20 became the G19 as it ended. On the Paris climate accords the United States was left isolated and friendless.

It is, apparently, where this US President wants to be as he seeks to turn his nation inward.

Donald Trump has a particular, and limited, skill-set. He has correctly identified an illness at the heart of the Western democracy. But he has no cure for it and seems to just want to exploit it.

He is a character drawn from America’s wild west, a travelling medicine showman selling moonshine remedies that will kill the patient.

And this week he underlined he has neither the desire nor the capacity to lead the world.

Given the US was always going to be one out on climate change, a deft American President would have found an issue around which he could rally most of the leaders.

He had the perfect vehicle — North Korea’s missile tests.

So, where was the G20 statement condemning North Korea? That would have put pressure on China and Russia? Other leaders expected it and they were prepared to back it but it never came.

There is a tendency among some hopeful souls to confuse the speeches written for Mr Trump with the thoughts of the man himself.

He did make some interesting, scripted, observations in Poland about defending the values of the West.

And Mr Trump is in a unique position — he is the one man who has the power to do something about it.

But it is the unscripted Mr Trump that is real. A man who barks out bile in 140 characters, who wastes his precious days as President at war with the West’s institutions — like the judiciary, independent government agencies and the free press.

He was an uneasy, awkward figure at this gathering and you got the strong sense some other leaders were trying to find the best way to work around him.

Mr Trump is a man who craves power because it burnishes his celebrity. To be constantly talking and talked about is all that really matters. And there is no value placed on the meaning of words. So what is said one day can be discarded the next.

So, what did we learn this week?

We learned Mr Trump has pressed fast forward on the decline of the US as a global leader. He managed to diminish his nation and to confuse and alienate his allies.

He will cede that power to China and Russia — two authoritarian states that will forge a very different set of rules for the 21st century.

Some will cheer the decline of America, but I think we’ll miss it when it is gone.

And that is the biggest threat to the values of the West which he claims to hold so dear.

ABC

Impossible Foods CEO: we want to eliminate all meat from human diets.

It’s the veggie burger that bleeds. When eaten, it tastes and feels remarkably similar in your mouth to a burger made from animal meat.

After a blaze of publicity, the US-based company behind it, Impossible Foods, is scaling up production. A new facility in California will open before the end of the year with the ability to produce four million burgers a month.

Impossible Foods founder Pat Brown explains the impact he hopes to have on our health, the future of the livestock industry and the natural environment.

We think we’ve made choices that have the net effect of making this better for consumers’ health than what it replaces. There are intrinsic safety issues with food from animals. You can’t make ground beef without faecal bacteria getting into it. It’s part of the process. That carries irreducible food safety hazards which we can readily avoid.

There is no cholesterol [in our burger] … there is a significant population of people for whom it [cholesterol] has negative health consequences. There is also data suggesting that mammalian meat triggers an inflammatory response in humans that has some negative health consequences that we don’t have with our product.

The ultimate goal is to develop a way to produce all the foods we [traditionally] get from animals much more sustainably using scalable ingredients from plants and make these foods delicious, nutritious and affordable.

If we succeed completely in that there would obviously still be cows, pigs and chickens but they would not be a significant part of the food system but kept around because they are interesting creatures.

This notion that somehow the land is going to waste if we don’t have sheep grazing on it is ludicrous. If we can produce a food with everything a consumer values using a twentieth of the land and a quarter of the water and a tiny fraction of the greenhouse gas footprint then what’s the good of turning grass into cows? Raising animals on marginal land is the biggest reason why over the past 40 years the total wild animals on earth have been cut by a factor of two..

Before becoming a vegan] I loved putting milk in my coffee and cereal, but plant-based milks don’t work for me so far. No-one is trying very hard to deliver the full experience of what consumers value from milk. We don’t want to follow the course of soya and almond milk. We’re after 100% of the market, not a niche of people avoiding meat or being health conscious.

To capture the whole market you have to deliver whatever it is that consumers value from that category of product. People have been making veggie burgers forever but not trying to make something that replicates the crave-able experience that meat lovers enjoy.

We’ve found a safer and more sustainable way to produce heme [the ingredient that gives the burger its meat-like colour and taste]. It is scalable and enables us to make an affordable product. Our customers are restaurants at the moment so they are the ones communicating to customers, not us. They are completely aware of how we make the heme protein. It is also made clear on our website.

The fear of food science is things being done to our food that we haven’t been fully informed about and don’t understand, as opposed to science. Every food you eat is a product of science and thousands of years of people investigating what things from nature are healthy and delicious to eat and how to prepare and combine them to make something better than what you started with and more than the sum of the parts.

The Guardian

Debunking The Fool. Trump’s Paris climate speech claims analyzed – Oliver Milman. 

“So we’re getting out. But we will start to negotiate, and we will see if we can make a deal that’s fair. And if we can, that’s great. And if we can’t, that’s fine.” 

So that’s that. After months of fevered speculation and lobbying, Trump sticks to his campaign pledge to withdraw the US from the Paris climate accord. He does so with a caveat that’s delivered rather casually – the US will renegotiate this pact, or maybe some other pact, aimed at ensuring the future liveability of the planet. But if it doesn’t work out, that’s OK.

“Compliance with the terms of the Paris accord and the onerous energy restrictions it has placed on the United States could cost America as much as 2.7m lost jobs by 2025, according to the National Economic Research Associates.”

Trump’s vision of a hobbled America, ransacked by pointless environmental regulation, draws upon a highly disputed study published in March. National Economic Research Associates has done work for front groups for coal companies in the past and this study was at the behest of the American Council for Capital Formation, which counts Exxon Mobil, the American Petroleum Institute and Charles Koch as major donors.

The Paris agreement itself places no “energy restrictions” on the US – it’s a voluntary agreement that leaves it up to countries to decide how to cut their emissions. But several economists have warned that leaving the Paris agreement will stymie clean energy investment and ensure the production of solar panels and wind turbines – the very blue-collar jobs Trump claims to value – will take place in China rather than the US.

It could get worse still – some countries are mulling a carbon “tariff” on US goods over Trump’s decision to swim against the energy transition that is underway. None of this will help a coal industry that was in decline long before the Paris deal. This is perhaps why business support for Paris is broad, uniting the likes of Facebook, Goldman Sachs, Apple and even BP.

“For example, under the agreement, China will be able to increase these emissions by a staggering number of years – 13. They can do whatever they want for 13 years. Not us. India makes its participation contingent on receiving billions and billions and billions of dollars in foreign aid from developed countries. There are many other examples. But the bottom line is that the Paris Accord is very unfair, at the highest level, to the United States.”

Trump repeatedly touches on a familiar theme of the US being taken advantage of by foreign ingrates. The Paris deal was considered a breakthrough because it required all nations to curb their emissions – including, crucially, China and India. Given that both these countries do not have more than a century of mass industrialization behind them, unlike the US, their commitments should be seen in context. Indeed, recent analysis has shown that China may have already peaked its coal use and will be reducing its emissions sooner than expected, although suspicions linger over its accounting methods.

Either way, both China and India have reiterated their commitment to the Paris deal in recent weeks and are investing heavily in renewable energy. That they are doing this with tens of millions of their people still without electricity and other basic services shows that perhaps it isn’t terribly unfair to expect the world’s wealthiest nation to do likewise.

“In short, the agreement doesn’t eliminate coal jobs, it just transfers those jobs out of America and the United States, and ships them to foreign countries.”

According to the Department of Energy there are about 373,000 Americans working in solar energy – more than double that of the coal industry. The coal sector has been shedding jobs for decades, driven by automation of work and, more recently, the abundance of cheap natural gas.

Major coal mining firms have conceded those jobs aren’t coming back and it’s not quite clear how American mining jobs can be shifted overseas given the US isn’t a coal exporter and US power plants aren’t crying out for extra minerals to keep the lights on. What’s more likely, according to economists, is that growth in renewable energy innovation and construction jobs will tip overseas, probably to China, which has committed to investing $360bn in the sector in the coming years.

“Our country will be at grave risk of brownouts and blackouts, our businesses will come to a halt in many cases, and the American family will suffer the consequences in the form of lost jobs and a very diminished quality of life.”

This dark vision would perhaps approach reality if a.) the only source of electricity in the US was coal, rather than a mix of nuclear, gas, coal and renewables, b.) the Paris agreement set any sort of binding limit on energy sources, and c.) the US government followed through with this by shutting down power plants rather than asking states to submit plans to transition away from polluting fossil fuels (as the Obama administration did). None of that has actually happened or was slated to happen.

“Even if the Paris agreement were implemented in full, with total compliance from all nations, it is estimated it would only produce a two-tenths of one degree – think of that; this much – Celsius reduction in global temperature by the year 2100. Tiny, tiny amount.”

White House “talking points” distributed before Trump’s speech cite MIT research for the 0.2-degree reduction. This prompted a swift rebuttal from the actual source, a collaboration between MIT and Climate Interactive. The researchers point out the reduction in expected warming from emissions cuts promised at Paris will be 0.9 degrees by 2100, not 0.2 degrees.

This still won’t be enough to avoid breaching the warming limit set out in the Paris deal but it’s worth considering that 0.9C is roughly the global temperature rise experienced since the industrial revolution. People living in southern Florida, or Bangladesh or beside a coral reef that provides food and a livelihood would have radically different lives if the global temperature increase was double its current level.

“The United States, under the Trump administration, will continue to be the cleanest and most environmentally friendly country on Earth. We’ll be the cleanest. We’re going to have the cleanest air. We’re going to have the cleanest water.”

Under the Trump administration, the Environmental Protection Agency (EPA) has paused or scrapped rules that prevent the dumping of mining waste into streams, curb emissions from vehicles and power plants and stop mercury and arsenic seeping into waterways. The EPA’s proposed budget also cuts measures that prevent lead in drinking water and also scraps clean-ups of the Great Lakes and the Gulf of Mexico and shrinks the funding of enforcement of pollution rules.

“And we’ll sit down with the Democrats and all of the people that represent either the Paris accord or something that we can do that’s much better than the Paris accord. And I think the people of our country will be thrilled, and I think then the people of the world will be thrilled. But until we do that, we’re out of the agreement.”

In common with some other policy areas, Trump seems to be believe his negotiating skills can overcome issues that leaders have grappled with for years. Paris came about after 20 years of often painful incremental manoeuvrings that included the disappointment of Copenhagen in 2009, and world leaders have already made clear they aren’t “thrilled” at the prospect of reversing this breakthrough.

France, Italy and Germany released a statement saying that the Paris deal can’t be redone, while the EU and China jointly declared the agreement was “irreversible”. The UK, Canada and Australia all reaffirmed their commitment to the agreement with Justin Trudeau, Canada’s prime minister, saying he is “deeply disappointed” with Trump’s decision. UN secretary general Antonio Guterres called it a “major disappointment.”

The US may return to Paris, with Trump or a future president, but there will be lingering diplomatic damage that will haunt the country on the international stage far more than the Kyoto reversal under George W Bush.

“At what point does America get demeaned? At what point do they start laughing at us as a country?”

Well, at this point there’s certainly not much laughter.

“I was elected to represent the citizens of Pittsburgh, not Paris.”

Here, Trump seems to confuse the venue of the UN climate agreement signing for the actual subject of the accord. It’s also worth noting that Bill Peduto, mayor of Pittsburgh, committed to the Paris deal, along with dozens of other US municipalities, after Trump’s announcement. About 65,000 people in Pennsylvania work in the renewable energy industry, more than mining, oil and gas combined.

“Of course, the world’s top polluters have no affirmative obligations under the green fund, which we terminated.”

Again Trump portrays the Paris deal as an onerous ball and chain around the ankle of a struggling America, which somehow isn’t now one of the world’s leading polluters. The climate fund is voluntary and Barack Obama pledged about $3bn to it. Given the scale of the climate challenge – rising seas, drought and disasters are already estimated to displace about 20 million people a year, according to the UN – even this funding is likely to be insufficient.

“And exiting the agreement protects the United States from future intrusions on the United States’ sovereignty and massive future legal liability. Believe me, we have massive legal liability if we stay in.”

One of the – ultimately successful – arguments put by opponents of the Paris deal to Trump was that his domestic agenda of revoking Obama-era environmental regulations would be jeopardised by the agreement. Architects of the deal have disputed this, pointing out that it is voluntary and non-binding and would carry no weight in a US court.

Ultimately, the only recourse to Trump’s decision will be through the ballot box. The notice period for withdrawing from the Paris deal expires in November 2020 – the month of the next presidential election. Climate change will likely be, for once, a live issue at the election.

Oliver Milman

The Guardian

The Example of Easter Island Shows Why Humanity Will Be Extinct Within 100 Years – Philip Perry. 

Like any other system, capitalism has its positive and negative qualities. Inarguably, it has lifted nearly a billion across the globe out of extreme poverty between 1990 and 2010. But as with other socioeconomic systems of the past, such as with feudalism, a time can come when revolutionary changes make such systems anachronistic. So too has capitalism’s time come, at least the kind which exploits the biosphere.

A more sophisticated system must replace it. One reason is because we are on the verge of a technological shift which will make almost all working and middle class jobs obsolete within the next 25 years or so. Currently, middle and working class families are already getting squeezed in developed countries. Their wages have remained stagnant for decades while costs have steadily risen.

Today, 15% of the US population is below the poverty line. If you include children under age 18, the number is 20%. All the gains in productivity over the last several decades have gone to the top one percent of income earners, while the economic prospects for the vast majority stagnated or worsened. Then there’s the environmental impact. We’re about to kick off the sixth great extinction event. and we’ll follow shortly after.

Big Think

‘Beyond the extreme’: Scientists marvel at ‘increasingly non-natural’ Arctic warmth – Jason Samenow. 

The Arctic is so warm and has been this warm for so long that scientists are struggling to explain it and are in disbelief. The climate of the Arctic is known to oscillate wildly, but scientists say this warmth is so extreme that humans surely have their hands in it and may well be changing how it operates.

Temperatures are far warmer than ever observed in modern records, and sea ice extent keeps setting record lows.

2016 was the warmest year on record in the Arctic, and 2017 has picked up right where it left off. “Arctic extreme (relative) warmth continues,”

Veteran Arctic climate scientists are stunned.

Washington Post

Donald Trump’s mission? To keep the US in the fossil age – George Monbiot. 

Recent research suggests that, if drastic action of the kind envisaged by the Paris agreement  on climate change is not taken, ice loss in Antarctica alone could raise sea levels by a metre this century, and by 15 metres in subsequent centuries. Combine this with the melting in Greenland and the thermal expansion of sea water, and you discover that many of the world’s great cities are at existential risk.

The climatic disruption of crucial agricultural zones – in North and Central America, the Middle East, Africa and much of Asia – presents a security threat that could dwarf all others. The civil war in Syria, unless resolute policies are adopted, looks like a glimpse of a possible global future.

These are not, if the risks materialise, shifts to which we can adapt. These crises will be bigger than our capacity to respond to them. They could lead to the rapid and radical simplification of society, which means, to put it brutally, the end of civilisations and many of the people they support. If this happens, it will amount to the greatest crime ever committed. And members of Trump’s proposed cabinet are among the leading perpetrators.

The Guardian

‘A cat in hell’s chance’ – why we’re losing the battle to keep global warming below 2C – Andrew Simms. 

It all seemed so simple in 2008. All we had was financial collapse, a cripplingly high oil price and global crop failures due to extreme weather events. In addition, my climate scientist colleague Dr Viki Johnson and I worked out that we had about 100 months before it would no longer be “likely” that global average surface temperatures could be held below a 2C rise, compared with pre-industrial times.

What’s so special about 2C? The simple answer is that it is a target that could be politically agreed on the international stage. It was first suggested in 1975 by the environmental economist William Nordhaus as an upper threshold beyond which we would arrive at a climate unrecognisable to humans. In 1990, the Stockholm Environment Institute recommended 2C as the maximum that should be tolerated, but noted: “Temperature increases beyond 1C may elicit rapid, unpredictable and non-linear responses that could lead to extensive ecosystem damage.”

To date, temperatures have risen by almost 1C since 1880. The effects of this warming are already being observed in melting ice, ocean levels rising, worse heat waves and other extreme weather events. There are negative impacts on farming, the disruption of plant and animal species on land and in the sea, extinctions, the disturbance of water supplies and food production and increased vulnerability, especially among people in poverty in low-income countries. But effects are global. So 2C was never seen as necessarily safe, just a guardrail between dangerous and very dangerous change.

The Guardian

When Scientists Hate Science – Paul A Offit. 

With Donald Trump’s recent picks to head the Environmental Protection Agency (Scott Pruitt) and the Energy Department (Rick Perry), it appears that science denialism has now been institutionalized. Pruitt, Perry, and Trump deny the fact that increasing levels of CO2 in the environment have trapped heat, causing an increase in the Earth’s surface temperature (“the greenhouse effect”), and consequent climate disruption. Although climate change is undeniable, the current administration has managed to deny it.

Climate change denialists couldn’t take their anti-science stance without the support of certain scientists. Although the overwhelming consensus among environmental scientists is that global warming is a real and present threat, a few disagree. Sadly, throughout history, science-denying scientists haven’t been hard to find.

In 1985, Barbara Loe Fisher, a prominent anti-vaccine activist, wrote A Shot in the Dark. In one chapter, Fisher claimed that vaccines caused autism. No one noticed. But when Andrew Wakefield, a respected scientist in the United Kingdom, published a paper in 1998 claiming that the measles-mumps-rubella (MMR) vaccine caused autism, everyone noticed. More than 1,500 articles trumpeting Wakefield’s theory appeared in newspapers and magazines across the globe. In the United Kingdom alone, thousands of parents stopped vaccinating their children with MMR; as a consequence, hundreds were hospitalized with measles and four children died from the disease.

Daily Beast

Without action on climate change, say goodbye to polar bears – Darryl Fears. 

“Short of action that effectively addresses the primary cause of diminishing sea ice it is unlikely that polar bears will be recovered.”

Global climate change, of course, is completely out of the control of Fish and Wildlife, a division of the Interior Department. An international effort to address the issue was signed about a year ago in Paris, but President-elect Donald Trump has questioned U.S. participation in a treaty that nearly 190 governments signed.

Trump has waffled in his perspective on climate change. When asked about the human link to climate change following his election, he said, “I think there is some connectivity. . . . It depends on how much.” He also said he would keep an open mind about the international climate accord and whether his administration will withdraw from it.

But the president-elect has also openly doubted the findings of more than 95 percent of climate scientists who say climate change is driven by human activity. In 2012, he tweeted that “the concept of global warming was created for and by the Chinese in order to make U.S. manufacturing non-competitive.”

Scientists say about 19 populations make up an estimated 25,000 to 31,000 bears, including a sub population of about 3,000 that roam Alaska. Estimates of their increases and declines go up and down depending on which population is being counted.

But researchers say 80 percent of the populations will almost certainly collapse if sea ice continues to decline. Air temperatures at the top of the world are rising twice as fast as temperatures in lower latitudes, resulting in significant ice melt, according to a report by the National Oceanic and Atmospheric Administration.

Under the effects of global warming, Alaska recorded temperatures nearly 20 degrees higher than the January average as warm air flowed north, NOAA said in an Arctic Report Card.

“We’re quite confident that absent action to address climate change, there would be very significant reduction in the range of polar bears,”

NZ Herald

Trump, Putin and the Pipelines to Nowhere – Alex Steffen. 

American voters regularly tell pollsters they don’t think climate change is a critically important election issue, so therefore the media decides it must not be an important political issue at all.

Unfortunately, that conventional wisdom blinds us to both to the actual bedrock reality of this era, and to — as I see it — the defining aim of the in-coming Trump administration: delaying climate action.

Trump has surrounded himself with more oil industry and oil industry connected people than any president in history (even George W. Bush). You can’t understand what’s going on with Trump unless you understand the oil industry… and you can’t understand the oil industry without understanding climate change.

Medium.com

NZ takes home ‘Fossil of the Day’ awards at COP22. 

New Zealand has been labelled a hypocrite, yet again, for its lack of action on climate change.

At the 22nd annual UN Climate Change Conference in Marrakech (COP22), the Climate Action Network awarded New Zealand two Fossil of the Day awards for blocking action on climate change.

NewsHub 

“Before the Flood – National Geographic & Leonardo DiCaprio”

YouTube 

A big world on a small planet. We are on track to lose two-thirds of wild animals by 2020.

More than 300 animal species are being eaten into extinction. 

The biggest cause of tumbling animal numbers is the destruction of wild areas for farming and logging: the majority of the Earth’s land area has now been impacted by humans, with just 15% protected for nature. Poaching and exploitation for food is another major factor, due to unsustainable fishing and hunting. The Guardian