7 - Global Warming

Summary

Global warming became a growing public concern following Jim Hansen’s US Senate testimony in 1988 asserting that the warming was happening. The Intergovernmental Panel on Climate Change (IPCC) was formed in response to this concern. The IPCC issues periodic assessments summarizing recent scientific developments relating to climate change. Climate models were used to attribute global warming to increasing concentrations of carbon dioxide and other greenhouse gases. Certain types of extreme weather can also be probabilistically attributed to these causes. The effect of aerosols and stochastic variability on the past global warming signal is described. The IPCC projects the global warming signal into the future using a range of carbon dioxide emission scenarios, resulting in different degrees of predicted warming. The importance of regional climate change and the difficulty of predicting it are discussed.