October 1, 2001: IPCC Report Concludes Human Activity is Major Causal Factor of Global Climate Change

The Intergovernmental Panel on Climate Change (IPCC) releases its third assessment report concluding that evidence indicates that human activity is the major force behind global warming. “The report analyzes the enormous body of observations of all parts of the climate system, concluding that this body of observations now gives a collective picture of a warming world…. A detailed study is made of human influence on climate and whether it can be identified with any more confidence than in 1996, concluding that there is new and stronger evidence that most of the observed warming observed over the last 50 years is attributable to human activities.” The panel also notes in its report that “the globally averaged surface temperature is projected to increase by 1.4 to 5.8 degrees Celsius over the period 1990 to 2100.” Roughly 1,000 experts from around the world participated in the drafting, revising and finalizing of the report and approximately 2,500 helped review it. [Intergovernmental Panel on Climate Change, 2001; CBS News, 6/19/2003; Boston Globe, 6/20/2003]