IPCC Working Group II Summary For Policymakers: Impacts, Adaptation and Vulnerability April 6, Slides for Communicating IPCC

Figure: Courtesy of IPCC

Working Group II: 174 Lead Authors 222 Contributing Authors 45 Review Editors Full Report 1,572 pages Summary for Policymakers

Overview: Consequences on the Ground Water Food Species Coasts Extreme Events Health

What the IPCC Means by “high confidence” The IPCC uses specific language, also indicated by number of asterisks, to describe confidence regarding statements: very high confidence*** (9 out of 10 chance), high confidence** (8 out of 10 chance), medium confidence* (5 out of 10 chance).

Human-induced climate change Observational evidence from all continents and most oceans shows that many natural systems are being affected by regional climate changes, particularly temperature increases. 89% of the 29,000 datasets that IPCC examined exhibited changes in the direction expected from warming.

Human-induced climate change It is likely that since 1970, human-induced warming has had a discernible influence on many physical and biological systems.

WATER Hundreds of millions of people will be exposed to increased water stress, which will get worse with increasing temperatures.** Water availability will decrease by as much as 30% in current drought-prone areas, in the dry tropics, and over much of the mid-latitudes, including the southwestern U.S.**

WATER The more than one sixth of the world population that currently lives near rivers that derive their water from glaciers and snow cover will see their water resources decline.** Water resources will be diminished in western North America as decreased snowpack in the mountains reduces summer river flows.***

FOOD Hunger risk is projected to increase for low latitude regions, in particular the seasonally dry tropics, as these areas will likely experience decreased crop yields for even small temperature increases. Regions in Africa will be particularly prone to hunger risk due to a reduction in the areas suitable for agriculture.**

FOOD Under slight temperature increases, higher latitude regions such as Northern Europe, North America, New Zealand, and temperate zone soybean regions of Latin America can adapt and benefit from increased growing season length, more precipitation, and/or less frost. However, if local mean average temperature rise exceeds 5.0 degrees Fahrenheit (2.8 degrees Celsius), crop yields in some regions are projected to decline in mid to high latitudes.*

SPECIES Species have already shifted their ranges to higher latitudes and higher elevations over the past several decades.*** Twenty to thirty percent of assessed plant and animal species on Earth will face extinction if the increase in global average temperature exceeds ºF ( ºC).*

SPECIES The capacity of many species and ecosystems to adapt will be exceeded in this century as climate change and its associated disturbances (including floods, drought, wildfire, insects, and ocean acidification) increase.** If sea surface temperature increases above seasonal average maximum level by around 1.8 degrees Fahrenheit (1 degree Celsius) coral bleaching of most corals occurs and above 3.6 degrees Fahrenheit (2 degrees Celsius) most corals die.**

COASTS Many millions more people are projected to be flooded every year due to sea-level rise by the 2080s.*** The most vulnerable populations are the largest mega-deltas of Asia and Africa and small islands.***

Extreme Events Where extreme weather events such as heat waves, droughts, fires, wildfires, floods, and severe storms become more intense an/or frequent, the economic and social costs of those events will increase. ** Disturbances from pests, diseases, and fire are projected to have increasing impacts on U.S. forests, with an extended fire season and large increases in area burned. ***

Human Health Projected climate change-related exposures will affect the health status of millions of people worldwide. U.S. cities that currently experience heat waves are expected to be challenged with an increased number, intensity, and duration of heat waves over the course of the century, with potential for negative health impacts. ***

Human Health Some infectious diseases, such as those carried by insects and rodents, may become a growing problem. ** The elderly, the children, and the poor of all nations are the most vulnerable populations and may be unable to cope with the climate change stresses.

Communicate the AR4 Actions Steps Write a letter-to-the-editor Monitor local news for climate contrarians and respond with letter-to-the-editor Contact your policymakers – state representatives, governor, congressperson – urge comprehensive legislation to reduce emissions Offer to give a presentation to local community group, religious group, or in a classroom Meet with an editorial board of your local paper

Communicate the AR4 Materials & Resources: AR4 Communicator Campaign IPCC Process Backgrounder Brochure on key findings of WGI Brochure on key findings of WGII (coming soon) PPT on key WGI findings PPT on key WGII findings (coming soon)

Communicate the AR4 I PCC Background, WGI Brochure Tips on talking the with media and policy makers Regional Climate Impacts al-effects-of-global.html al-effects-of-global.html Questions:

THANK YOU!

WATER Many rivers that derive water at their source from melting glaciers or snow will have earlier peak runoff in Spring and an overall increase in run-off, at least in the short term.** The temporary increase in water flows will not always be welcome. For example, glacier melt in the Himalayas will increase flooding and rock avalanche risks, while flash flood risks will increase in inland areas in Europe.***

Temperatures are Relative to Today Global average temperature increase in these slides is expressed as temperature rise above today. Add 0.8 degrees Celsius to convert these to temperature rise above pre-industrial (about 1750) levels. The numbers and figures in the summary for policymakers uses temperature rise above 1990 levels which is 0.6 degrees Celsius above pre- industrial levels.

Links for US regional impacts: Northeast: Great Lakes: California: Gulf coast: Iowa: the-hawkeye-state.html. Alaska: impact-assessment.html.

References The Summary for Policymakers released February 2, 2007, was the first contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (the Working Group I technical report is titled Climate Change 2007:The Physical Science Basis). Available at The Summary for Policymakers released April 6, 2007, was the second contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (the Working Group II technical report is titled Climate Change 2007:Impacts, Adaptation, and Vulnerability). Available at For more background on IPCC history and process, visit For 4 page handout on WG1 that can accompany this presentation go to

The IPCC based its projections on six emission scenarios, running each one through sophisticated climate simulation programs. Governance Development Local Global EnvironmentalEconomic A1B1 B2A2 Adapted from Arnell et al. (2004). Global Environmental Change, 14:3-20 A1B A1FI A1T

Population at 2100 Governance Development Local Global EnvironmentalEconomic A1B1 B2A2 Adapted from Arnell et al. (2004). Global Environmental Change, 14:3-20

Gross Domestic Product Growth at 2100 Governance Development Local Global EnvironmentalEconomic A1B1 B2A2 Adapted from Arnell et al. (2004). Global Environmental Change, 14:3-20

Energy Use at 2100 Governance Development Local Global EnvironmentalEconomic A1B1 B2A2 Adapted from Arnell et al. (2004). Global Environmental Change, 14:3-20

Governance Development Local Global EnvironmentalEconomic B1 B2A2 Adapted from Arnell et al. (2004). Global Environmental Change, 14:3-20 A1B A1FI A1T Technological Change at 2100 Country A Country B Country C

Source: IPCC Climate Change 2007: The Physical Science Basis—Summary for Policymakers. Washington Post NOAA Washington Projected Changes at the End of the 21 st Century

Source: IPCC Climate Change 2007: The Physical Science Basis—Summary for Policymakers. Change in Precipitation for relative to Dec – Feb Scenario A1B More DryMore Wet