Under GOP pressure, federal agency pulls climate change chapter from official manual for U.S. judges

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Under pressure from Republican state attorneys general, the agency that advises the U.S. Supreme Court and federal judges on scientific and technical matters has withdrawn the entirety of its content on climate change from a new judicial reference manual.

The move by the Federal Judicial Center leaves judges without any official support on how to weigh evidence about basic weather and climate changes just as numerous climate cases make their way through state and federal courts, including two on the docket of the U.S. Supreme Court for the current term.

The center was created as an education agency and is chaired by Chief Justice John Roberts. By law, it is charged with overseeing court policies and researching technical and scientific issues that come before the court. The Supreme Court press office did not respond to a request for comment.

On Dec. 31, 2025, the center released the first update in 15 years of its 1,682-page peer-reviewed guide, called the “Reference Manual on Scientific Evidence,” including more than 90 pages defining climate terminology and describing the state of scientific consensus on climate change and the methods used to attribute specific weather events to climate warming and its causes. The chapter acknowledges uncertainty in some areas of climate science; it generally reflects the conclusions of the U.N.’s Intergovernmental Panel on Climate Change.

The manual, widely cited and relied upon by law clerks and justices, is produced in partnership with the National Academies of Sciences, Engineering and Medicine and also includes chapters on artificial intelligence, DNA identification and epidemiology, among other subjects. It is considered among the most important and trusted guides for justices grappling with technical material, in large part because it is endorsed by the judicial branch itself.