Under pressure from Republican state attorneys general, the agency that advises the U.S. Supreme Court and federal judges on scientific and technical issues has removed its entire content on climate change from a new judicial reference manual.
The gesture of Federal Judicial Center leaves judges without any official support on how to weigh evidence on fundamental weather and climate change, just as numerous climate cases are coming before state and federal courts, including two on the U.S. Supreme Court docket for the current term.
The center was established as an educational agency and is chaired by Chief Justice John Roberts. By law, he is responsible for overseeing court policies and researching technical and scientific issues brought before the courts. The Supreme Court’s press office did not respond to a request for comment.
On December 31, 2025, the center released the first update in 15 years to its 1,682-page peer-reviewed guide, titled “Reference manual on scientific evidence“, comprising more than 90 pages defining climate terminology and describing the state of the scientific consensus on climate change and the methods used to attribute specific weather events to global warming and its causes. The chapter acknowledges uncertainty in some areas of climate science; it generally reflects the findings of the UN Intergovernmental Panel on Climate Change.
The handbook, widely cited and used by court officers and judges, 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 topics. It is considered one of the most important and reliable guides for judges dealing with technical material, largely because it is endorsed by the judiciary itself.
The release of the climate change chapter, however, drew immediate criticism from conservatives, who say the article is unfavorable to oil and gas producers and represents an attempt by activists to influence the opinions of judges deliberating on pending cases.
The withdrawal comes as a number of lawsuits seek to hold oil and gas companies responsible for damages caused by climate change, which have been scientifically linked to emissions produced by burning fossil fuels. Republican attorneys general have repeatedly criticized the lawsuits, accusing liberal groups of using tort law to enact regulatory policy and supporting efforts to have the cases dismissed or moved to federal court.
On February 2, more than 20 Republican attorneys general wrote to the House and Senate Judiciary Committees stating that the manual is “tainted by biased authors, reviewers, and sources involved in ongoing litigation” and that it is an “inappropriate attempt to rig the results of cases in favor of one party.” The group encouraged the House Judiciary Committee, chaired by Ohio Republican Jim Jordan, to include the publication in a recently announced investigation into a program of the Environmental Law Institutea nonpartisan research group, to educate judges about climate change.
The next day, the Federalist Society, a conservative legal organization, convened a panel to discuss the publication of the manual. The moderator said this went against the Federal Judicial Center’s role as a “neutral arbiter of facts” and warned that “the inclusion of a climate science section advances an ideological agenda.”
The chapter reflects “the assumption that some sets of evidence are automatically more credible than others,” West Virginia Attorney General Michael Williams told the panel audience. He suggests that “some issues are resolved while still pending before the courts.”
On February 6, the director of the Federal Judicial Center, Judge Robin Rosenberg of the Southern District of Florida, wrote to West Virginia Attorney General John McCuskey that the center “omitted the chapter on climate science.”
In their letter last week, the attorneys general raised concerns that one of the authors of the climate chapter is employed by Columbia University’s Sabin Center for Climate Change Law and that, in the report’s footnotes, the authors thank that program’s executive director, Michael Burger. Burger, who declined to comment, is counsel to the Sher Edling law firm, which represents several plaintiffs in climate cases, including the city of Honolulu.
The objections from state attorneys general represent “bad faith criticism that ultimately aims to suppress scientific information,” said Jessica Wentz, one of the chapter’s authors. The removal of the chapter, she said, “will be used to advance the narrative that there is a debate on even the most fundamental aspects of climate change.”
Wentz said she has never been a witness or attorney in any climate litigation and that it was disingenuous for attorneys general to object to elements of the climate chapter — which recognizes the consensus that human activity is responsible for warming — because they are the subject of contested litigation. None of the major climate trials she is aware of debate the science of warming and instead address the question of whether fossil fuel companies are responsible. “The infusion of bias,” Wentz said, comes not from exposure to scientific information but “from the suppression of that scientific information.”
The National Academies of Sciences, Engineering, and Medicine have retained a copy of the original manual on its own website, even though the Federal Judicial Center removed the version containing the climate change chapter from its own site. A representative for the center declined to comment, and members of the House Judiciary Committee could not immediately be reached for comment.
