Climate science is being removed from U.S. judicial reference manuals - and scientific societies are pushing back
A chapter on climate science has been removed from the Reference Manual on Scientific Evidence, the standard guide that federal judges use when evaluating scientific testimony and evidence. The removal was carried out by the Federal Judiciary Center (FJC). Shortly afterward, 21 state attorneys general sent a letter urging the National Academies of Sciences, Engineering, and Medicine (NASEM) to omit similar climate guidance from its own materials.
The American Meteorological Society, joined by the Ecological Society of America, the American Statistical Association, the Woodwell Climate Research Center, and the American Institute of Biological Sciences, has issued a formal statement calling both actions inconsistent with the scientific evidence.
What was removed and why it matters
The removed chapter summarized the state of climate science for a legal audience - judges and attorneys who are not climate scientists but who increasingly encounter climate-related questions in litigation. Cases involving emissions regulations, environmental damage, insurance liability, and infrastructure planning all require courts to evaluate scientific claims. The reference manual existed to help them do so competently.
According to the AMS statement, the chapter was consistent with every other comprehensive, rigorous assessment of climate science the signatory organizations are familiar with. It reflected conclusions drawn from decades of research by thousands of independent scientists across dozens of fields, including atmospheric physics, oceanography, glaciology, biogeochemistry, and economics.
The statement expresses two specific concerns. First, that removing the chapter will leave public officials - particularly those in the legal system - without access to the best available scientific understanding of climate change. Second, that the actions of people in positions of power will discourage scientists from contributing expertise to public decision-making in the future.
The political context
The FJC's decision and the attorneys general's letter arrive during a period of heightened political tension over climate policy in the United States. Climate litigation has expanded significantly in recent years, with cities, states, and advocacy groups filing lawsuits against fossil fuel companies and challenging government policies. The scientific evidence summarized in reference manuals like the one in question often serves as foundational material in these cases.
Removing that material does not change the underlying science. But it does change access. Judges who previously had a vetted, peer-reviewed summary available as a reference tool would now need to evaluate competing expert claims without that baseline - a situation that benefits whichever party can afford more persuasive expert witnesses rather than whichever position the evidence supports.
What the societies affirm
The statement reiterates several scientific conclusions that the signatory organizations consider well-established: climate change is occurring at an unusual rate and scale compared to natural variability; human activities, primarily greenhouse gas emissions, are the primary driver; the impacts are harmful and increasing; and these findings reflect overwhelming agreement among researchers who study the evidence.
The organizations urged reinstatement of the climate science chapter and reaffirmed their willingness to assist public officials in accessing and applying current scientific knowledge.
What this does not resolve
A statement from scientific societies has no legal force. The FJC is not obligated to reverse its decision, and the National Academies will make their own determination about whether to include climate content. The 21 attorneys general who wrote to NASEM represent states whose political leadership is broadly skeptical of climate regulation, and their letter carries political rather than scientific weight.
The deeper tension is structural. Scientific reference materials are designed to provide neutral, evidence-based guidance. When the process of curating those materials becomes subject to political pressure, the materials lose the perceived neutrality that makes them useful. Whether the FJC's removal was motivated by political considerations, administrative ones, or some combination is not addressed in the AMS statement - but the timing and the coordinated attorney general letter make the political dimension difficult to ignore.
Climate science spans dozens of disciplines and involves tens of thousands of practicing scientists. The evidence base is deep and extensively reviewed. The question is not whether the science supports the conclusions in the removed chapter - it does. The question is whether institutions tasked with informing public officials will continue to present that evidence, or whether political pressure will succeed in making it harder for courts and policymakers to find it.