Skip navigationMobileHelpSite map Default text size Larger text size High contrast page

IPCC Fourth Assessment Report (AR4 Report)

The Intergovernmental Panel on Climate Change (IPCC) was established by the World Meteorological Organization (WMO) and United Nations Environment Programme (UNEP) to improve the understanding of climate change, its potential impacts and options for adaptation and mitigation.

The main activity of the IPCC is to provide in regular intervals Assessment Reports of the state of knowledge on climate change. The latest one is Climate Change 2007, the Fourth IPCC Assessment Report.

Interpreting the IPCC report

As the single biggest contributor to the report from the UK, the Met Office is ideally placed to help you understand what the report is saying. Met Office Consulting offers advice and information on interpreting the science and its impacts.

Working Groups

The reports by the three Working Groups provide a comprehensive and up-to-date assessment, by many hundreds of climate scientists worldwide, of the current state of knowledge on climate change.

Working Group I: The Physical Science Basis of Climate Change

This report addressed the key areas of climate change research including that the warming of the climate system is unequivocal and most of the recent warming is very likely due to human activity.

Read the Working Group I summary report

Working Group II: Impacts, Adaptation and Vulnerability

This report examined the future likely impacts of climate change on the planet, its vulnerability and capacity to adapt. The content was wide-ranging, outlining predicted impacts for all continents and identifying major systems with specific detail. Management of the report was carried out by the Met Office Hadley Centre.

Read the Working Group II summary report

Working Group III: Mitigation of Climate Change

Working Group III reported on mitigation, looking at greenhouse gas (GHG) emission trends and ways to mitigate their effects. It reported on sustainable development and assessed the gaps in our knowledge.

Read the Working Group III summary report

The full reports can be downloaded from the IPCC website.