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Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report

The Intergovernmental Panel on Climate Change (IPCC) released its Fourth Assessment Report in 2007. This report determined that the warming of the Earth's climate system is unequivocal. 

About 30 Canadian experts, including several from Environment Canada, served leading roles in the preparation of this report.  Many more Canadians were involved in the report as contributing authors and reviewers. 

About the Fourth Assessment Report

The IPCC completed its Fourth Assessment Report, the culmination of six years of work, in early 2007. The Fourth Assessment is composed of four volumes. The first volume of the AR4 to be completed was that of Working Group I. Climate Change 2007: The Physical Science Basis assessed scientific knowledge on the natural and human drivers of climate change, observed changes in climate, the ability of science to attribute changes to different causes and projections for future climate change. The Working Group II report, Climate Change 2007: Impacts, Adaptation and Vulnerability, assessed current and future consequences of climate change on social and natural systems, and options for adapting to future climate change. The Working Group III report, Climate Change 2007: Mitigation, assessed options for reducing greenhouse gas emissions and other ways of mitigating climate change. The final volume, the Synthesis Report, brought together the key findings of all three working groups in one document.

Climate Change 2007: The Physical Science Basis

Climate Change 2007: Impacts, Adaptation and Vulnerability

Climate Change 2007: Mitigation

Climate Change 2007: Synthesis Report