This paper quantifies the coastal protection provided by mangroves for 42 developing countries in the current climate, and a future climate change scenario with a one-meter sea level rise and 10 percent intensification of storms. The benefits of the coastal protection provided by mangroves are measured in terms of population and gross domestic product at a reduced risk from inundation; the loss of benefits under climate change is measured as the increased population and gross domestic product at risk. The findings demonstrate that although sea level rise and increased storm intensity would increase storm surge areas and the amounts of built resources at risk, the greatest impact is the expected loss of mangroves.