Even with global emissions of greenhouse gases drastically reduced in the coming years, the global annual average temperature is expected to be 2^oC above pre-industrial levels by 2050. A 2^oC warmer world will experience more intense rainfall and more frequent and more intense droughts, floods, heat waves, and other extreme weather events. Households, communities, and planners need to put in place initiatives that “reduce the vulnerability of natural and human systems against actual and expected climate change effects” (IPCC 2007). Without such adaptation, development progress will be threatened—perhaps even reversed.

To shed light on adaptation costs the Economics of Adaptation to Climate Change (EACC) study was initiated by the World Bank in early 2008, funded by the governments of the Netherlands, Switzerland, and the United Kingdom. Its objectives are to develop an estimate of adaptation costs for developing countries and to help decisionmakers in developing countries understand and assess the risks posed by climate change and design better strategies to adapt to climate change.

This initial study report, which focuses on the first objective, finds that the cost between 2010 and 2050 of adapting to an  pproximately 2^oC warmer world by 2050 is in the range of $70 billion to $100 billion a year. This range is of the same order of magnitude as the foreign aid that developed countries now give developing countries each year, but it is still a very low percentage of the wealth of countries as measured by their GDP.