The Federal Judicial Center has just withdrawn its chapter on Climate Science from the Reference Manual for Scientific Evidence 4th Edition (Federal Judicial Center and the National Academies of Sciences, Engineering, and Medicine, 2025). This happened astonishing quickly. The latest edition of the Reference Manual was released in late December 2025, and on January 29, twenty-seven state attorney generals sent a joint letter of protest about the Climate Science chapter, stating that it was unprofessionally biased toward the claims of climate activists, rather than a neutral resource from judges. The Federal Judicial Center (FJC) did not protest, but simply withdrew the chapter on February 6, less than a month after publication. This is an unprecedented action. The FJC’s unwillingness to defend the Climate Science chapter is strong evidence, albeit not dispositive, that the accusation of unprofessional bias was true.
A swift review does indeed reveal worrisome aspects of the Climate Science chapter—blithe assumptions that collectively weaken its credibility. It refers to the Intergovernmental Panel on Climate Change (IPCC) as a leading authority, without referring to the many published accounts of the IPCC’s unreliability. It summarizes climate science’s dependence on complex systems, modeling, and statistical operations, without ever giving full weight to the depth of the criticisms about the role of improper accounting of these complexities and procedures in the conclusions of climate science. The lack of the mention of the irreproducibility crisis of modern science (reproducibility crisis, replication crisis), and how this might affect the conclusions of climate scientists, is a red flag.
Then, from a legal vantage point, one might mention that the entire idea that there are climatic “harms” which can be addressed by the legal system is more an activist aspiration than a question of law and precedent. An informed layman would have deep reservations—particularly about a document which is meant, precisely, to inform an audience of laymen—judges, generally not trained in the details of science, who must judge cases that require a substantial minimum of scientific knowledge. A document that aims at impartiality ought at least to acknowledge the common knowledge of a skeptic of climate activists, but the Climate Science chapter simply ignored these critiques. That is enough for a layman to think that the FJS was right to withdraw the chapter.
This episode matters—and as more than just another incident of the climate science wars. For one thing, it highlights the importance of the Reference Manual for Scientific Evidence, and more broadly of the legal system’s treatment of science. Americans—and, specifically, policy institute personnel—who care about the role of science in public policy usually focus on the role of governmental regulation, above all federal regulation. Regulations matter. But so, collectively, does the judicial system—for judges and juries make decisions about legal cases whose stakes collectively rise to the hundreds of billions, or trillions, of dollars. The operation of the judicial system is diffuse, and not so easily amenable to public policy reform. But it matters, both in terms of straightforward dollars and cents and in terms of the incentives given to American corporations, at least as much as our governmental regulations.
The Reference Manual plays a key role in how the judicial system treats science. Most judges, understandably, are not scientific experts—becoming an expert in the law is sufficiently challenging, and worthy of the American public’s admiration and respect. Yet they must preside over cases that turn on advanced questions of scientific fact, and on how to weigh the conflicting testimony of different experts in science. They must do this in a wide range of different scientific fields—witness the lengthy table of contents in the Reference Manual, and its 1,662 pages. A judge faced with a case turning on advanced scientific knowledge turns to the Reference Manual, provided by the avowedly nonpartisan institutions of the Federal Judicial Center and the National Academies of Sciences, Engineering, and Medicine, to provide a quick precis of the relevant scientific issues. That precis, in turn, will allow the judge to do his job while dealing with formidably technical subject matters.
Politicization of science in the judicial realm, then, has turned here on activists inserting themselves into a nonpartisan realm, and altering the Reference Manual so that judges unfamiliar with climate science will issue distorted rulings. The alterations are more or less subtle. Reformers who oppose such activists cannot simply change a regulation: they must, as the states attorney generals did, write a letter that carefully documents scientific and legal distortions in the Reference Manual, and convince the FJC to withdraw an offending chapter. This is not the usual means of political warfare. But both the climate activists offensive action, and the defensive action of the states attorney general, mattered as much as the more headline-grabbing wars about federal regulation of scientific issues.
The National Association of Scholars (NAS) cares about the search for truth in the university, and we have concerned ourselves with how abuses in the search for truth in the sciences has affected government policy—and, contrariwise, how abuses of government policy have distorted the academic search for truth in the sciences. Our focus has been more on federal, state, and local laws and regulations. However, we also care about the interrelations of the scientific search for truth and the operation of the judiciary. We plan to gather comments from various scientists on the Reference Manual and its strengths and weaknesses. We do this because it matters in itself, and also as a way to focus public attention on the broader relationship of the search for scientific truth and the operations of the legal system. We have substantive commitments to oppose activism in the scientific realm that impedes or distorts the open scientific search for truth—and we are delighted, therefore, that another improper climate-activist abuse has been quashed. But our mission, above all, is to make the role of science in the legal system a matter of public interest, discussion, and thoughtful and concerted reform.
NAS also cares about the Reference Manual, and the role of science in the judicial system, because it speaks to the goals of K-12 and undergraduate education. There are many ways to articulate what science education should achieve. But one way to put it is that science education ought to prepare a judge, an educated man who is a layman in science, to be able to read and evaluate the Reference Manual. Indeed, science education should prepare a body of jurors to a similar level of competence—to be able, in a courtroom, to understand and to evaluate the opposing arguments of lawyers, and the testimony of scientific experts. Our work on The Franklin Standards: Model K-12 State Science Standards, for example, is meant to help educate K-12 students not least so that they can serve as informed jurors in a legal case that turns on scientific issues.
We need education reform, and content rich standards in K-12 and undergraduate education, not least so that government by the people will continue to mean something real in America’s courtrooms.
The Reference Manual is a keystone for the role of science in the courts, and we will continue to focus our attention upon evaluating its accuracy. We also will continue to cast a particularly skeptical eye upon activist intrusions into the operations of the judiciary. Ultimately, we care more that Americans know that the Reference Manual matters, and that the role of science in our courts matters.
The activists cared enough about the Reference Manual that they tried to cook the book. That fact alone should tell Americans that they need to pay attention—and make sure the book gets written right.
Photo by Mika Baumeister on Unsplash
