This national scientific assessment integrates, evaluates, and interprets the findings of the U.S. Climate Change Science Program and draws from and synthesizes findings from previous assessments of the science. It analyzes current trends in global change, both natural and human-induced, and projects major trends for the future. It analyzes the effects of these changes on the natural environment, ag., water resources, social systems, energy production and use, transport., and human health. This assessment addresses not only climate change, but also other change in the global environment ¿ including water resources, oceans, atmospheric chemistry, land productivity, and ecological systems¿that may alter the capacity of Earth to sustain life. Ill.