American jurisprudence celebrates an adversary system of justice. Lawyers are relied upon to argue competing narratives subject, among other things, to cross-examination, the greatest instrument ever invented for the discovery of truth. Final judgments are made by impartial, independent judges or juries. And Supreme Court precedent requires federal judges to act as "gatekeepers" to ensure scientific testimony is both relevant and reliable.

In accord with this jurisprudential gospel, the Federal Judicial Center (FJC) recently said it withdrew the climate science chapter from its Reference Manual on Scientific Evidence prepared as a neutral resource for federal judges. In so doing, the FJC tacitly admitted that the chapter had entered the domain of climate advocacy in lieu of presenting undisputed facts justifying judicial notice under Rule 201 of the Federal Rules of Evidence like the heliocentric theory of the universe.

But more should be done to honor and protect our adversarial system of justice. The chapter remains in the public domain on the National Academies website. The FJC continues to partner with climate‑advocacy organizations like the Climate Judiciary Project to favor plaintiffs in climate litigation against U.S. energy producers. Scrupulous impartiality is the hallmark of the judicial branch. Even an appearance of bias requires recusal under federal law. As the United States Supreme Court ordained in Offutt v. United States, “justice requires the appearance of justice.”

The FJC is tasked with providing judges with neutral, educational information about the “basic tenets of key scientific fields.” Its mission is “not intended to tell judges what is good science and what is not,” as the FJC professed when the previous edition of the manual was released. What has changed?

The FJC’s bias is in plain view. The chapter’s authors – Jessica Wentz and Radley Horton – and reviewers – Michael Gerrard and Michael Burger – have been integers in litigation targeting energy companies via Columbia’s climate law program.

For several years, Burger has supervised a United Nations report endorsing climate litigation as a “key mechanism” for “holding major emitters accountable.” Burger, in particular, is Of Counsel at Sher Edling, which represents most of the plaintiffs in the climate lawsuits. He is not merely a passive advisor in the litigation. His name is on complaints in the cases filed by Delaware in 2020, Honolulu in 2020, and New York City in 2021. Burger’s role in active litigation was never publicly disclosed by the chapter’s authors, the FJC, or the National Academies.

In addition, Gerrard has frequently filed amicus briefs supporting plaintiffs in climate cases. The FJC chapter echoes these advocates while denying even cameo appearances to credible dissents—for example, the Department of Energy’s 2025 climate report.

The FJC’s bias finds expression in the chapter’s affirmation of highly contested research. Its manual endorses attribution studies attempting to link specific climate impacts to emissions from individual corporations, summoning the so-called “Carbon Majors” report. It attributes global emissions to fossil fuel producers by assigning downstream consumer emissions back to companies. Author Richard Heede argued “fossil producers bear substantial moral, financial, and possibly legal responsibility for the foreseeable and foreseen climate impacts.” The manual declares Heede’s tenuous thesis may establish legal causation, notwithstanding that PolitiFact has acknowledged that research reliably establishing such attribution has yet to surface. The FJC has abandoned scientific neutrality for advocacy.

The chapter further exhibits bias by citing partisan activists like Michael Mann while omitting scholarly critiques or alternative analytical frameworks—particularly the credible views of government scientists outside the climate-litigation ecosystem.

The Department of Energy’s 2025 Critical Review of Impacts of Greenhouse Gas Emissions on the U.S. Climate documents substantial uncertainty in climate sensitivity estimates. Among other things, it finds that many U.S. extreme weather events confirm no clear long-term trends. It cautions against misplaced confidence in attribution methods that rely heavily on models and counterfactual assumptions. The FJP climate chapter, however, misinforms judges that attribution science is “unequivocal,” that specific damages can be quantified, and that uncertainty should not impede relief. In doing so, the FJC has defected from our adversarial system of justice fortified by cross-examination.

Article III of the United States Constitution and due process guarantee every litigant judicial impartiality. If a research arm of the judiciary takes sides on highly contested scientific issues dispositive of litigation claims, an appearance of judicial bias is born. As 27 state attorneys general asserted in a letter to the FJC, it “undermines the judiciary’s impartiality and places a thumb on one side of the scale… even as these issues are pending before” the courts. The precedent lies around like a loaded weapon, ready to spread to all controversial litigation, including pharmaceutical liability cases, election disputes, or Second Amendment litigation. Public confidence in evenhanded justice will be shaken.

In sum, the FJC must insist on removing the chapter from the version on the National Academies website. It should resist collaboration with notorious advocacy organizations such as the Environmental Law Institute’s Climate Judiciary Project that has its own legal axes to grind. The adversary process featuring strict judicial impartiality is optimal for securing justice—the end of government and civil society.