In 2009 the World Bank launched the Economics of Adaptation to Climate Change (EACC) study to provide up-to-date and consistent estimates of adaptation costs for developing countries. The EACC study addresses many of the shortcomings found in the adaptation cost literature. First, it defines 'adaptation costs' as those additional costs of development due to climate change, thereby avoiding confounding the costs of closing the development deficit and the implicit adaptation deficit. Second, the study covers eight major sectors: infrastructure, coastal zones, water supply, agriculture, fisheries, forests and ecosystems, human health, and extreme weather events. Third, it employs common population and GDP growth trajectories across sectors and uses two climate scenarios to capture the full spread of model predictions. Finally, the EACC study uses an innovative methodology for aggregating costs at the sector level within a country, and across countries. Under these assumptions, the global price tag for the developing world of adapting to an approximately 2 degrees C warmer world by 2050 is US70-100 billion per year for 2010-2050.