The 2014 U.S. National Climate Assessment: A Focus on the Science

The 2014 U.S. National Climate Assessment (NCA) draws upon the latest scientific understanding of climate and climate change, synthesizing recent advances in the understanding of the science of climate change, and providing a succinct overview of the past and projected effects of climate change on the United States. The NCA was conducted under the auspices of the Global Change Research Act of 1990 that requires reporting to the President and the Congress that integrates, evaluates, and interprets the state of the science and the potential effects of global change on the natural environment, agriculture, energy production and use, land and water resources, transportation, human health and welfare, human social systems, and biological diversity. Regional and sector analyses of potential impacts of the changing climate are central to the assessment. The new assessment analyzes of the observed trends and projected future climate changes. Along with increasing temperatures over all regions of the U.S., the pattern of precipitation change in general is one of increases generally at higher northern latitudes and drying in the tropics and subtropics over land. Scientific analyses indicate a strong link between changing trends in severe weather events and the changing climate. This presentation describes the major findings from the 2014 U.S. National Climate Assessment.