The Fifth US National Climate Assessment was published in November 2023 during the Biden/Harris administration. Here’s the announcement by Zeke Hausfather on X/Twitter:
After three years of work by a team of over 750 scientists, we are releasing the US 5th National Climate Assessment today!
— Zeke Hausfather (@hausfath) November 14, 2023
We see greater impacts of climate change on the US since the 2018 NCA4 report, but also some encouraging signs of progress.https://t.co/2WZOLOXoKo
The “NCA5” report begins as follows:
The Global Change Research Act of 1990 mandates that the US Global Change Research Program (USGCRP) deliver a report to Congress and the President not less frequently than every four years that “integrates, evaluates, and interprets the findings of the Program and discusses the scientific uncertainties associated with such findings; analyzes the effects of global change on the natural environment, agriculture, energy production and use, land and water resources, transportation, human health and welfare, human social systems, and biological diversity; and analyzes current trends in global change, both human-induced and natural, and projects major trends for the subsequent 25 to 100 years.”
You may well have noticed that Kamala Harris lost the subsequent election? Hence the Sixth US National Climate Assessment will be prepared during the term of the current Trump/Vance administration.
The first move by Trump et al. was for the US Department of Energy to commission a “Climate Working Group” to produce a report catchily entitled “A Critical Review of Impacts of Greenhouse Gas Emissions on the U.S. Climate“, which was published in July 2025. The authors of the report were listed alphabetically as John Christy Ph.D., Judith Curry Ph.D., Steven Koonin Ph.D., Ross McKitrick Ph.D. and Roy Spencer Ph.D.
Regular readers will recognise some or all of those names, and it will not surprise you to learn that there was plenty of pushback from a wide range of climate scientists. In particular, the “Climate Experts’ Review of the DOE Climate Working Group Report“, led by Andrew Dessler and Robert Kopp was published at the end of September 2025. This report begins as follows:
Continue reading The Sixth US National Climate Assessment
