Climate Change: Summary of the IPCC Fourth Assessment Report November 2007

About the International Panel on Climate Change (IPCC) The IPCC was established to provide the decision-makers and others interested in climate change with an objective source of information about climate change. Its role is to assess on a comprehensive, objective, open and transparent basis the latest scientific, technical and socio-economic literature produced worldwide relevant to the understanding of the risk of human-induced climate change, its observed and projected impacts, and options for adaptation and mitigation.

About the International Panel on Climate Change (IPCC) The IPCC is a scientific intergovernmental body set up by the World Meteorological Organization (WMO) and by the United Nations Environment Programme (UNEP). Its constituency is made of : –The governments: the IPCC is open to all member countries of WMO and UNEP. –The scientists: hundreds of scientists all over the world contribute to the work of the IPCC as authors, contributors and reviewers.

About the IPCC Fourth Assessment Report +2,500 expert reviewers 800 contributing authors 450 lead authors from 130 countries. - Vision of UN Secretary General Ban Ki-Moon, November 12, 2007

Controversies in the Popular Theory of Global Warming Complexity! Model-based. Alternative causes for warming? Politicized science? Unwarranted Doom and Gloom? Anti-capitalism agenda? Global warming leading to global cooling?

Observations

Figure 1.3

Alpine Glacier Retreat Retreat of 7 miles and 800 meter thinning. Source: National Snow and Ice Data Center

Sea Ice Loss Over Time Source: National Snow and Ice Data Center

Figure 4.10 Sea ice extent in the Nordic Sea

Northern Hemisphere Sea Ice Extent (1979 versus 2003) Image courtesy of NASA-Goddard Space Flight Center

Northern Hemisphere Sea Ice Thickness

Figure 4.5 Timing of Ice Formation and Breakup

Greenland Ice Sheet Meltdown

Observed and modeled ocean temp. changes Hansen et al., Science vol. 308

Trends in Various Parameters

What Impacts Climate?

What Impacts Radiation Balance?

Figure 2.1

Must Quantify Radiation Balance

Hansen et al., Science vol. 308 What Controls Global Warming?

Where Do You Go To Find Records of Climate Change? Antarctica Vostok ice core

Greenhouse Gas Concentrations Over Time and Correlation to 18 O

FAQ 2.1, Figure 1

Rates of Change in Greenhouse Gases

Figure 2.6 Atmospheric concentrations of CFS and associated anthropogenic compounds

Figure 2.18

What goes into the models?

FAQ 9.2, Figure 1 Confidence in models?

Figure Model Evolution

Hansen et al., Science vol. 308 What Controls Global Warming?

How do the models work

Models of Future Warming Will temperature increase be uniform across the globe? +10°F

Differential Temp Change The results are based on climate change simulations made with the Coupled Global Climate Model developed by Environment Canada. From Atlas of Canada Annual Temperature Change from to (°C)

Variability in Temp and Rainfall with Latitude and Model

Comparison of Warming Models

Comparison of Warming and Precipitation Models – Winter vs Summer

Figure 10.12

Figure 10.19

What are Ramifications for Shelled Organisms in the Ocean?

Figure 5.13

Sea Level Rise Under Different Scenarios Press presentation, Nov. 17, 2007

FAQ 5.1, Figure 1

Contributions to Sea Level Rise

Greenland Ice Sheet Meltdown

The Concept of Tipping Points

Inertia in the System

General Predictions of Impacts over 21st Century Source - IPCC WGII TAR 2001Thanks to Martha Groom

Source: R. Nicholls, Middlesex University in the U.K. Meteorological Office Climate Change and Its Impacts: A Global Perspective. People at Risk from a 17-inch Sea-level Rise by the 2080s* *Assuming 1990s level of flood protection

Source: EPA Louisiana Shoreline Change with a 20-inch Rise in Sea Level Lake Charles Lafayette Baton Rouge Morgan City Houma New Orleans Gulf of Mexico Land Lost

South Florida Shoreline Change with a 1m Rise in Sea Level

Projections of Greenland Ice Volume

Models of Future Global Warming 2050 Sea Level Rise Associated with collapse of West Antarctic Ice Sheet