Many parts of the developing world are subject to variable and extreme climate, the impacts of which impede development and point to the need to improve the understanding and management of climate risks. These needs are being amplified by human-caused climate change. The Intergovernmental Panel on Climate Change (IPCC) concluded in its 2001 report that much of the developing world is highly vulnerable to adverse impacts from climate change. But the IPCC also concluded that the vulnerabilities of developing countries are too little studied and too poorly understood to enable determination of adaptation strategies that would be effective at reducing risks. These authoritative volumes, resulting from the work of the Assessments of Impacts and Adaptations to Climate Change (AIACC) project launched by the IPCC in 2002, are the first to provide a comprehensive investigation of the issues at stake.