National Climate Assessment provides the scientific foundation to understanding the global climate

The U.S. Global Climate Change Program recently released an assessment of climate science that offers a disturbing view of climate change on our planet. The National Climate Assessment is intended to support the United States’ national assessment of climate-related risks and inform responses.

This latest assessment found that the annual average surface air temperature has increased about 1.8 degrees over the last 115 years, making this period the warmest in the history of modern civilization. Indeed, the last three years alone have been the hottest on record. Based on thousands of scientific studies from around the world, the conclusion is crystal clear: human activities, particularly those that emit greenhouse gases, are the main reason our planet has warmed since the mid-twentieth century.

Other indicators of climate change are being seen around the world, including documented changes in surface, atmospheric and oceanic temperatures, melting glaciers, diminishing snow cover, shrinking sea ice, rising sea levels, ocean acidification and increasing atmospheric water vapor. For example, global sea level rise has increased seven to eight inches since 1900, and heat waves, forest fires and heavy rainfall are occurring with more regularity and intensity.

Established by a presidential initiative in 1988 and mandated by Congress under the Global Change Research Act of 1990, the Global Change Research Program includes representatives from 13 federal agencies who conduct or use research on global climate change. This group is legally required to release a national climate assessment every four years that:

• Informs the United States about observed changes, the current status of the climate and anticipated trends for the future;
• Integrates scientific information from multiple sources and sectors to highlight key findings and significant gaps in knowledge;
• Establishes consistent methods for evaluating climate impacts in the United States in the context of broader global change; and
• Is used by United States government, citizens, communities and businesses as they create more sustainable and environmentally sound plans for the future.

Learn more about climate change in the Chesapeake Bay watershed or explore the goals of our Climate Resiliency Workgroup.