The GCRA requires USGCRP to develop an assessment of global change "not less frequently than every four years."
In response to this mandate, USGCRP has periodically produced an assessment titled the National Climate Assessment; these NCAs have synthesized the state of climate science and climate-related risks and impacts across each U.S. region and across major sectors of the economy.
The NCA does not direct federal agencies to take specific actions; rather, it provides scientific information that agencies, policymakers, and stakeholders may use to support decisions such as those related to infrastructure resilience, disaster preparedness, economic risk assessment, and environmental planning.
To date, USGCRP has released five NCAs:
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The NCAs have been written by hundreds of experts, including scientists working in federal government, academia, and the private sector.
Each NCA has undergone multiple rounds of expert and governmental review, including evaluation by federal agencies, external experts, the public, and a NASEM review committee.
According to USGCRP in 2023, NCA5 was the most comprehensive analysis of climate change in the United States.
In 2024, USGCRP began developing the Sixth National Climate Assessment (NCA6).
To comply with the requirement to produce an assessment every four years, the deadline to submit NCA6 to Congress is 2027.
In early 2025, under the second Trump Administration, work on NCA6 reportedly stopped and the report's authors were reportedly dismissed.
~from:
U.S. Global Change Research Program (USGCRP): Overview and Considerations for Congress
U.S. Global Change Research Program (USGCRP): Overview and Considerations for Congress
https://www.congress.gov/crs-product/R48478