The recently published report of the Intergovernmental Panel on Climate Change (IPCC, 2007) suggests clear evidence of climate change impacts. Global average air and ocean temperatures are rising. As a result, snow and ice are melting, leading to a rise in sea levels. Extreme weather events and hazards, such as flooding, heat waves and cyclones, are becoming more frequent, and the geographical and temporal clustering of precipitation patterns is shifting. In short, our hydrologic and ecological systems are changing. While an extensive body of literature has already developed around the question of international cooperation as a necessary prerequisite for mitigating climate change (Dunn and Falvin, 2002; Haas, 2004; Caney, 2005), other research indicates that some of its effects are already irreversible (IPCC, 2007). Thus scholars are also increasingly examining the possible role of international cooperation in the adaptation to climate change impacts.
There are at least three distinct roles for international cooperation in climate change mitigation and adaptation, which differ from each other in terms of their global communitarian basis. First, international cooperation can lead to positive-sum outcomes for the particular states involved. For example, the pooling of resources for the provision of public goods such as data, information and know-how, if shared in a non-exclusive way, can produce positive externalities. Second, confidence-building measures between two or more states can help to avoid conflicts over the use of increasingly uncertain stocks and flows of some internationally shared resources.