Global climate change is likely to cause rising sea levels and increased frequency and severity of flooding in low-lying areas. Evidence is needed on the magnitude and distribution of potential impacts, as well on possible avenues for adaptation. This study will quantify the potential impacts of climate change in Bangladesh, one of the world’s most vulnerable nations. First, comprehensive data on Bangladesh’s history of natural disasters such as floods, cyclones, and storm surges are compiled and then combined with economic, health and other data from multiple sources to estimate the historical relationship between these natural disasters and socioeconomic outcomes. Second, these estimates are combined with projected changes in frequency and severity of natural disasters in order to predict the magnitude and distribution of impacts. In parallel, the study uses current data to characterize the welfare effect of rising sea levels, in particular the loss in productivity associated with population displacement from the regions of Bangladesh projected to become permanently underwater. This project will inform climate change policies by providing detailed estimates of potential health and economic costs for the largest at-risk population in the world. The results will help the government to develop regional mitigation policies. This project will also have knowledge externalities, since it will provide new data on historical and projected flood patterns, improve access to Bangladeshi health and socioeconomic outcomes data, and create a methodological template for similar data creation and analysis for other at-risk areas.