For Diving Into Climate Science
NCA5 is the most up-to-date and comprehensive assessment of climate change in the United States, providing authoritative, decision-relevant information on how people across the country are experiencing climate change, the risks we face now and in the future, and actions underway to reduce greenhouse gas emissions and build resilience.
Creator: the U.S. Global Change Research Program
Release date: November 2023, removed from federal websites in July 2025 (see Document History).
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Led by USGCRP and its 14 member agencies, NCA5 draws on the expertise of nearly 500 authors and 250 contributors from every state, as well as Guam, Puerto Rico, and the U.S. Virgin Islands.
The extensively reviewed Assessment includes input from public comment and engagement, and an external peer review conducted by the National Academies of Sciences, Engineering, and Medicine. The report meets the requirements of the Global Change Research Act, which mandates a quadrennial assessment of our understanding of global change and its impacts on the United States. Additional information on the report development process and timeline is available in NCA5’s Process Appendix.
NCA5, and all previous assessments, went offline on June 30, 2025, when the web hosting contract for the U.S. Global Change Research Project expired after being allowed to lapse. NASA pledged to put the assessments back up, but abandoned the plan on July 15, 2025.
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