SciDev.Net

The Third Assessment Report of the IPCC's Working Group 1 builds on past assessments and incorporates new results from the past five years of climate change. It descibes the current state of udnerstanding of the cliamte system, and provides estiamtes of its projected future evolution and their uncertainties.

Many hundreds of scientists from around the world participated in the preparation and review of the report, which states that "there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities".

The Third Assessment Report of the Intergovernmental Panel on Climate Change, published in 2001, is the most comprehensive and authoritative source of information on climate change. Its conclusions confirm and strengthen those of the previous reports: human-induced climate change is a reality and most of the effects will be negative, but a range of mitigation opportunities is available to address the problem.

The Report finds that most of the earth’s warming over the past 50 years can be attributed to human activities, and that its effects are already being felt. Global temperature is expected to increase by 1.4 to 5.8ºC over the next century, a significant increase on the projections of the 1995 Second Assessment Report. This briefing paper summarises the findings of the Third Assessment Report and the debates underpinning them, and discusses the likely outcomes of the Report.