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general, the agency that advises the U.S. Supreme Court and federal judges on scientific and technical matters has withdrawn the entirety of its content on climate change from a new judicial reference manual.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.
Its publication of the chapter on climate change, however, drew immediate criticism from conservatives, who allege that the section is slanted against oil and gas producers and represents an effort by activists to sway the opinion of judges deliberating on current cases.
The withdrawal comes as a number of lawsuits seek to hold oil and gas companies accountable for the damage caused by climate change, which has been scientifically linked to the emissions produced by burning fossil fuels. Republican attorneys general have repeatedly criticized these lawsuits, accusing liberal groups of using tort law to enact regulatory policy and supporting efforts to have cases dismissed or moved into federal court.
On Feb. 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 case outcomes in favor of one side.” 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 by the Environmental Law Institute, a nonpartisan research group, to educate justices on climate change.
The next day, the Federalist Society, a conservative judicial organization, convened a panel to discuss the publication of the manual. The moderator said it runs counter to the Federal Judicial Center’s role as a “neutral arbiter of fact” and warned that the “inclusion of a climate science section advances an ideological agenda.”
The chapter reflects “an assumption that certain bodies of evidence are automatically more credible than others,” Michael Williams, West Virginia’s solicitor general, told the panel’s audience. It suggests “certain questions are resolved when they’re actually still being litigated before courts.”
On Feb. 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 “has omitted the climate science chapter.”
In their letter last week, the attorneys general raised concerns that one of the authors of the climate chapter is employed by the Sabin Center for Climate Change Law at Columbia University and that in the footnotes of the report the authors thank the executive director of that program, Michael Burger. Burger, who declined to comment, is of counsel to the law firm Sher Edling, which represents several of the plaintiffs in the climate cases, including the city of Honolulu.
The objections by the state attorneys general represent “a bad-faith critique that is ultimately aimed at repressing scientific information,” Jessica Wentz, one of the chapter’s authors, said. The withdrawal of the chapter, she said, “is going to be used to advance this narrative that there is a debate about even the most fundamental aspects of climate change.”
Wentz said that she has never been a witness or served as counsel in any climate litigation and that it is disingenuous for the attorneys general to object to the material in the climate chapter — which acknowledges the consensus that human activity is responsible for warming — because it is the subject of contested litigation. None of the major climate lawsuits that she is aware of debate the science of warming and instead address questions about fossil fuel companies’ responsibility. “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 has maintained a copy of the original manual on its own website even as the Federal Judicial Center has removed the version with the climate change chapter from its own. A representative from the center declined to comment, and members from the House Judiciary Committee could not immediately be reached for comment.
