Scientific assessments are essential tools for linking science and decision making. They survey and synthesize science, within and between disciplines and across sectors and regions. They highlight key knowledge that can improve policy choices and identify significant gaps that can limit effective decision making. Assessments also track progress by identifying changes in the condition of the Earth, changes in human response, and advances in science over time.

Today, delivering on a legal mandate and the President’s Climate Action Plan, the U.S. Global Change Research Program released the 3rd National Climate Assessment. The report, only available digitally, can be found at

The 3rd National Climate Assessment (NCA) report confirms that climate change is affecting every region of the country and key sectors of the U.S. economy and society, underscoring the need to combat the threats climate change presents and increase the preparedness and resilience of American communities. Specifically, the NCA:
  • Informs the Nation 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 the U.S. Government, citizens, communities, and businesses as they create more sustainable and environmentally sound plans for the future.

From the report: “It is important that these findings and response options be shared broadly to inform citizens and communities across our nation. Climate change presents a major challenge for society. This report advances our understanding of that challenge and the need for the American people to prepare for and respond to its far-reaching implications.”

The findings of the Third National Climate Assessment are fully traceable and supported by metadata through the Global Change Information System (GCIS), a new gateway to Federal global change information that delivers on goals set in USGCRP’s 2012–2021 Strategic Plan. The GCIS enables traceability between environmental data streams (such as observations from sensors and outputs from models) and the resulting scientific findings and publications. Going forward, the GCIS is intended to expand to provide this traceability for other key reports.
The Third National Climate Assessment was developed over four years by hundreds of the Nation’s top climate scientists and technical experts, guided by a 60-member Federal Advisory Committee, and informed by extensive input from the public and outside organizations gathered through town hall meetings, public comment opportunities, and technical workshops across the country.