The Federal Judicial Center’s new Reference Manual on Scientific Evidence is under fire from nearly half of the states, who say the guide has shifted from neutral instruction to overt climate advocacy. State attorneys general argue the manual’s climate chapter and its contributors tilt the judiciary toward predetermined outcomes in cases involving fossil fuels. This piece lays out who objected, what they said, and why Republican leaders want a wider inquiry into influence over federal judges.
Republican state attorneys general, led by Nebraska Attorney General Mike Hilgers, have formally asked congressional Judiciary leaders to broaden an existing probe into climate influence over judges. They say the Federal Judicial Center, which is supposed to be nonpartisan, published a new edition that favors a particular side of the climate debate. At root, their gripe is that judges rely on this manual behind closed doors and deserve unbiased, balanced materials.
The contested volume is the 1,600-page “Reference Manual on Scientific Evidence,” whose fourth edition includes a foreword from Justice Elena Kagan and multiple chapters touching on climate science. Critics point to extensive footnotes and cited work from known climate advocates and academics, arguing those citations reflect activist viewpoints. The attorneys general say that turns what should be neutral judicial education into a vehicle for advocacy.
“Those same improper influence concerns apply to the Federal Judicial Center and its new ‘Reference Manual on Scientific Evidence’,” the attorney generals wrote in part. They argue the manual treats certain disputed methods as settled science and fails to disclose conflicts among authors and reviewers. That, they say, raises ethics questions and risks tilting case outcomes against traditional energy producers and users.
State leaders singled out contributions from figures such as environmental law expert Jessica Wentz and climatologist Michael Mann, describing their inclusion as evidence of agenda-driven sourcing. They point to Wentz’s court brief opposing the Willow drilling project in Alaska, which includes the line “the world needs to phase out fossil fuels as rapidly as possible in order to avert potentially catastrophic levels of global warming and climate change.” To critics, that kind of rhetoric has no place in a supposedly neutral judicial manual.
Multiple Republican attorneys general signed the letter urging an expanded probe, including officials from Alaska, Florida, West Virginia, Alabama, Kentucky and a broader coalition across plains and southern states. Their concern is institutional: the manual’s ubiquity means any bias could ripple through courts nationwide. If judges are guided by materials that reflect one side of a heated policy fight, fairness and public confidence suffer.
West Virginia Attorney General JB McCuskey warned that placing the judiciary “firmly on one side of some of the most hotly disputed questions” undermines impartiality and tilts the scale. He and others also sent a separate note directly to the Federal Judicial Center’s director insisting the manual remain a trusted, neutral resource. The message from state officials is simple: educational tools for judges must not become subtle advocacy.
Industry and conservative groups echoed the point, arguing taxpayer-funded materials should not embed disputed, plaintiff-driven climate theories into judges’ reference texts. One critic called the trend “legal warfare” that uses courts to turn political goals into permanent policy. Those voices stress protecting the bench from what they see as outcome-shaping science cloaked as pedagogy.
Nebraska’s Hilgers summed up the worry plainly: “When the same advocates and experts who are actively litigating climate cases help write and review a chapter that will be used by federal judges behind the scenes, it raises obvious and serious concerns about the impartiality of the judicial system.” He added, “Nebraskans, and all Americans, deserve courts that are neutral and fair.”
Several signers requested Congress expand its review to include the Federal Judicial Center’s manual and the processes that produced it, arguing that only a broader inquiry can reveal whether improper influence is at work. When asked about the scrutiny of her citations and footnotes, one academic involved in the manual declined to comment. Congressional offices and the FJC were contacted for response as part of the unfolding oversight push.
