Climate science demonstrates how greenhouse gas (GHG) emissions alter atmospheric GHG concentrations and affect temperature and precipitation, and helps generate climate extremes and hazards. Climate-related disaster risk is the expected value of losses often represented as the probability of occurrence of hazardous events multiplied by the impacts. Risks result from the interaction of three elements: hazard; exposure; vulnerability. Exposure is the presence of people, livelihoods, ecosystems, environmental services, resources, infrastructure, and economic, social, and cultural assets in places and settings that could be adversely affected by natural hazards. Cyclone Nargis and Hurricane Sandy are indications that both developing and developed countries face climate-related disaster risks. The numbers of people affected have nevertheless been on the rise everywhere. Economic damages from comparable events are greater in developed countries, indicative of higher-valued assets and structures, and the higher cost of rebuilding. Deaths from natural disasters concentrate in poorer developing countries.