Climate change, interacting with changes in land use and demographics, will affect important human dimensions in the United States, especially those related to human health, settlements and welfare. The challenges presented by population growth, an aging population, migration patterns, and urban and coastal development will be compounded by changes in temperature, precipitation, and extreme climate-related events. Climate change will affect where people choose to live, work, and play. Among likely climate changes are changes in the intensity and frequency of precipitation, more frequent heat waves, less frequent cold waves, more persistent and extreme drought conditions and associated water shortages, changes in minimum and maximum temperatures, potential increases in the intensity and frequency of extreme tropical storms, measurable sea-level rise and increases in the occurrence of coastal and riverine flooding. In response to these anticipated changes, the United States may develop and deploy strategies for mitigating greenhouse gases and for adapting to unavoidable individual and collective impacts of climate change.

The SAP 4.6 focuses on impacts of global climate change, especially impacts on three broad dimensions of the human condition: human health, human settlements, and human welfare. It was prepared by a team of experts from academia, government, and the private sector in response to the mandate of the U.S. Climate Change Science Program’s Strategic Plan (2003). The assessment examines potential impacts of climate change on human society, opportunities for adaptation, and associated recommendations for addressing data gaps and near- and long-term research goals.