This and previous Administrations have periodically conducted congressionally mandated National Climate Assessments to assess and inform the Nation about the impact of climate change. The U.S. Global Change Research Program (USGCRP), which includes 13 Federal agencies responsible for coordinating climate-science research, oversees the assessment process.
The third, and most recent, National Climate Assessment (NCA3) was released in 2014 and remains an indispensable reference for decision makers across the country. It demonstrated that a changing climate caused primarily by the buildup of carbon dioxide in the atmosphere poses a threat to the health and welfare of all Americans. NCA3 is easily accessible via a searchable, web-based platform, which allows any reader to see the studies and data supporting all of the Assessment’s key findings.
The fourth National Climate Assessment (NCA4), intended to build upon the successes and address some gaps of NCA3, is scheduled to be completed in 2018. Several special reports and products that serve as foundational elements for NCA4 are underway or have already been developed:
Today, the Administration is releasing for public comment the draft Climate Science Special Report, which, when finalized, will provide the physical-science foundation for NCA4. This report is a comprehensive and updated assessment of the state of knowledge on human-induced climate change, including observed and future projected changes in temperatures, precipitation patterns, extreme-weather events, sea-level rise, and ocean acidification, focused primarily on the United States.
Earlier this year, the USGCRP produced an assessment of The Impacts of Climate Change on Human Health in the United States, demonstrating more clearly than ever before that climate-change impacts endanger human health by affecting food and water sources, air quality, weather, and human interactions with the built and natural environments. This assessment provides valuable insight for NCA4 on emerging climate-health linkages, including those that affect the Nation’s most vulnerable.
Recognizing the need for increasingly local climate information, the National Oceanic and Atmospheric Administration will soon be releasing fact sheets on observed and projected climate change within each state. These fact sheets, based on the latest science consistent with the Climate Science Special Report, provide regionally tailored information and will serve as a resource for the sectoral and regional analyses within NCA4, as well as to state and local decision makers.
An interagency task force is finalizing locally specific sea-level rise scenarios over multiple decades for the entire U.S. coastline, including Alaska and Hawaii. These scenarios take into account not only the most recent science of global sea-level rise, but also regional characteristics, such as land subsidence and climate-induced changes in ocean currents. This product, also anticipated to be released soon, will serve the Nation’s coastal communities by providing place-based information to support long-term planning and decision making.
The scope and outline of NCA4 have been developed and have received public comments earlier this year. Technical inputs are being accepted through January 15, 2017. Chapter leadership—largely solicited and selected through an open, public call—is now in place for all 27 chapters. Author teams are also coming together. Regional stakeholder workshops and other public engagement opportunities are being planned throughout 2017. Key areas to improve upon, relative to previous assessments, include more quantitative information of risks at regional scales, more specific information about adaptation needs and opportunities, and an evaluation of the implications for the United States of climate-change impacts in other parts of the world.
To find out more about the NCA4 process and how you may be able to engage, visit the USGCRP.
The National Climate Assessment remains a critical resource for the Nation, as increasingly more communities, state and tribal governments, local municipalities, and American businesses seek tailored climate information to inform risk-reduction measures and resilience planning. This Administration is proud to have advanced National Climate Assessments and to have set a path forward for robust assessments in the future.
Tamara Dickinson is Principal Assistant Director for Environment and Energy at the White House Office of Science and Technology Policy.
Michael Kuperberg is Executive Director of the U.S. Global Change Research Program.