Human-induced climate change is a major and growing concern to U.S. policymakers and citizens who need the best available science to inform their decisions. This report responds to that need by synthesizing the large and growing body of science that deals with how climate is changing, and the impacts of these changes on the United States, now and in the future. This report also explores some options for adapting to climate change and its impacts that could help in coping with the amount of additional warming that is inevitable as a result of past and ongoing emissions of heat-trapping gases and other human-induced changes.