National Climate Assessment

What is the National Climate Assessment (NCA)?

The NCA informs the nation about already observed climate changes, the current status of climate, and anticipated trends for the future. Conducted under the mandate of the United States Global Change Research Act of 1990, which requires a report to the U.S. President and the Congress every four years, the NCA:

  • 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.

In 2018, the United States Global Change Research Program released the Fourth National Climate Assessment (NCA4), Volume II (Impacts, Risks, and Adaptation in the United States). The report was written by more than 300 Federal and non-Federal authors representing a range of expertise, a number of whom were selected through a public call for nominations. The Hawai‘i and Pacific Islands chapter has 11 authors and 77 regional contributors, and is backed by more than 250 citations from published articles, reports, and books. The report was extensively reviewed by the public and experts, including federal agencies and a panel of the National Academy of Sciences.

Key NCA resources