Removal of Chapter on Climate Science from Judicial Instruction Manual: U.S. Federal Legal Research Institution Becomes Political Pressure Point

Author: Paul Gould

November 11, 2026

The National Academy of Sciences building, Washington, DC [Image credit: Túrelio/Wikimedia Commons]

On August 7, 2026, the U.S. National Academy of Sciences (NAS) removed a climate science chapter intended for a judicial reference manual from its website. Published in collaboration with the Federal Judicial Center (FJC), the research and education agency of the federal judiciary, the manual, known as the Reference Manual on Scientific Evidence, Fourth Edition, is meant to support “judges in managing cases involving complex scientific…evidence by describing the basic tenets of key scientific fields and by providing examples of cases in which that evidence has been used.” While there are more directly pressing issues concerning the dangers of climate change, this action, taken after the chapter had been initially removed from the manual itself by the Federal Judicial Center in February, marks an important measure by the FJC, and its parent agency the Judicial Conference of the United States, in refusing to acknowledge the established scientific consensus on climate change. 

The Reference Guide on Climate Science, the formal name of the removed chapter, was compiled by Jessica Wentz, LL.M., a non-resident Senior Fellow at the Sabin Center for Climate Change Law at Columbia Law School, and Radley Horton, Ph.D., a professor at the Columbia Climate School, also of Columbia University. They chose to focus exclusively on the physical science aspects of climate science, as the broad, multi-disciplinary nature of the field makes guidance on all of its many areas difficult to “establish precise boundaries for this field.” 

The chapter touches on aspects of the climate that would be familiar to many readers, including the greenhouse effect and glacial melting, and provides robust and comprehensive frameworks on the foundational components of climate science, climate change detection, and projections about future rates and impacts of climate change. The presentation of their material suggests a strong understanding by the authors of the underlying research, and they present the research in an unbiased and professional manner. Throughout the chapter, however, the authors attest to the uncertainty inherent in several parts of the ongoing investigations of various climate science issues, particularly the lack of clarity and specificity with which predictions can be made about local and regional climate developments. They delineate between areas where great confidence can be placed in the accuracy of prediction models, as in the case of global mean temperature, and projections where less certainty is warranted, such as with precipitation. 

The chapter was subsequently removed after allegations were raised by 27 state attorneys general in a letter addressed to Judge Robin L. Rosenberg, federal district court judge and director of the FJC. It accuses Wentz and Horton of ignoring alternative authoritative experts and favoring sources that are one-sided and only offer “flawed conclusions.” The letter takes issue with the support Wentz and Horton afford to widely-held and agreed upon perspectives on human-caused climate change, arguing that they are in “serious dispute.” This support of these viewpoints, when implemented as part of a design for use by judges in assigning injury liability, is supposedly premature. The alternative experts proffered in the letter merely state an objection to a data source without providing evidence to support his allegation, and another provides opinion which is then used to reject any portion of the source’s research from approval. In citing these experts, the attorneys general misrepresent the tone and material presented in the Reference Guide. Wentz and Horton are very measured in their approach to acknowledging consensus, and more importantly lack thereof, on various issues, methods, data models, and more. They address, for example, the complexities of forecasting precipitation levels across various regions and time frames, and the difficulty of ascribing blame for harms derived from climate change, even abstaining from suggesting a standard of culpability in the event of such harms, acknowledging this question rightly to be the purview of the judges they are seeking to inform. The letter from the attorneys general completely mischaracterizes the statements in the chapter on these issues and others, arguing that much more substantive claims are made. In instances where strong declarations are given, such as on the existence of anthropogenic climate change, it resorts to distortion and ignorance in order to contest the chapter’s pronouncements. 

Admittedly, the chapter does offer guidance on issues that were in dispute at the time it was published, and the letter of the attorneys general addresses this, but the material in the chapter is presented in such a way that leaves broad discretion to judges to decide on the legal issues in question. The claims that the attorneys general describe as ‘substantive’ only cover easily verified scientific claims, and most statements by Wentz and Horton leave the consideration of liability for damages or mechanisms by which such liability is assigned up to judicial bodies. For instance, the chapter refers to the Fifth National Climate Assessment and the Sixth Assessment Report from the Intergovernmental Panel on Climate Change, both of which concluded with a high degree of certainty that an increase in the magnitude, frequency, and duration of extreme heat events is a direct and foreseeable consequence of a warming climate. This claim is cited by the attorney letter as one that attributes unsuitably broad impacts to climate change, which in turn “support the most substantial findings of liability for climate-driven plaintiffs.” Arguing that the magnitude of the impacts of climate change and their associated liability represents some disingenuous or insidious motivation denigrates both the findings of the scientists that was done, and trivializes the effects from these impacts. Indeed, if the letter of the attorneys general is meant to refer to the unequivocal claims made in the chapter, and thereby seeks to subject the verifiability of science to legal standards of proof in order for any scientific findings to be deemed true, then the need for the Reference Guide is even more urgent. 

What makes these events so concerning, and particularly the decision by the FJC to remove the chapter, is that radical political considerations were allowed to supersede rigorous scientific research and dialogue. President Trump posted on his social media account about the Reference Guide, several months after the initial oppositional letter was published. Both actions served to bring national attention to the chapter and lead to its eventual removal. There are few more pressing global concerns than the ongoing and future impacts of anthropogenic climate change, and this chapter by NAS and FJC sought to provide reasoned guidance on dealing with the types of issues that will continue to be adjudicated in the coming decades without overstepping their mandate. In removing the Reference Guide, the federal judiciary, and by extension the United States, loses the opportunity to implement sound and reasonable judgement in climate cases. 

Article 7 of the Universal Declaration of Human Rights guarantees equal protection of the law, without any form of discrimination, in a similar manner to the Fourteenth Amendment to the United States Constitution. In preventing the adoption of the measures advocated in the Reference Guide, the federal judiciary is unable to use settled science to determine case outcomes and thus is blocked from fulfilling its responsibility to our legal system of providing this equal protection. When political wrangling is allowed to bypass the application of rigorous scientific evidence in the application of law, a grievous violation of the sanctity of equal protection is inevitable. 

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Glossary

• Abstaining - to choose not to do or have something : to refrain deliberately and often with an effort of self-denial from an action or practice.

• Address - to direct the efforts or attention of (oneself). 

• Adjudicate - to make an official decision about who is right in (a dispute) : to settle judicially. 

• Adoption - the act or process of giving official acceptance or approval to something.

• Advocate - to support or argue for (a cause, policy, etc.).

• Allegation - a positive assertion especially of misconduct.

• Anthropogenic climate change - refers to the significant alterations in Earth's climate resulting from human activities, particularly since the Industrial Revolution. Key contributors to this phenomenon include modifications to the planet's surface and the development of energy technologies that lead to increased greenhouse gas emissions.

• Ascribing - to refer to a supposed cause, source, or author : to say or think that (something) is caused by, comes from, or is associated with a particular person or thing.

• Aspect - a particular status or phase in which something appears or may be regarded.

• Attest - to affirm to be true or genuine.

• Broad - having ample extent from side to side or between limits. 

• Bypass - to neglect or ignore usually intentionally. 

• Collaboration - to work jointly with others or together especially in an intellectual endeavor.

• Compile - to compose out of materials from other documents. 

• Component - a constituent part : ingredient.

• Comprehensive - covering completely or broadly.

• Consensus - general agreement (as of opinion or fact) among a group of people or things.

• Culpability - responsibility for wrongdoing or failure : the quality or state of being culpable.

• Delineate - to describe, portray, or set forth with accuracy or in detail.

• Discretion - the quality of having or showing discernment or good judgment.

• Discrimination - the act, practice, or an instance of unfairly treating a person or group differently from other people or groups on a class or categorical basis (such as race, religion, gender, or sexual orientation) : prejudiced or prejudicial outlook or practice. 

• Distortion - the act of twisting or altering something out of its true, natural, or original state. 

• Evidence - something (as testimony, a writing, or an object) submitted at a judicial or administrative proceeding for the purpose of proving a party's case.

• Exclusively - in a way limited to a single person, group, category, method, etc.

• Federal district court - the trial courts of the U.S. federal judiciary. There is one district court for each of the 94 federal judicial districts. Each district covers one U.S. state or a portion of a state. 

• Federal Judicial Center - the education and research agency of the federal judiciary of the United States. It was established by Pub. L. 90–219 in 1967, at the recommendation of the Judicial Conference of the United States.

• Federal judiciary - one of the three branches of the U.S. federal government organized under the U.S. Constitution and laws of the federal government. 

• Foundational - fundamental.

• Framework - a basic conceptional structure (as of ideas).

• Greenhouse effect - occurs when heat-trapping gases in a planet's atmosphere prevent the planet from losing heat to space, raising its surface temperature. 

• Grievous - causing or characterized by severe pain, suffering, or sorrow.

• Implement - to take steps to put into practice.

• Inclusion -  to take in or comprise as a part of a whole or group.

• Inevitable - incapable of being avoided or evaded.

• Inherent - belonging to the basic nature of something or someone : involved in the constitution or essential character of something.

• Judicial Conference - created by the United States Congress in 1922 with the principal objective of framing policy guidelines for administration of judicial courts in the United States.

• Liability - obligated according to law or equity.

• Mandate - an authoritative command.

• Measured - deliberate, calculated.

• Mischaracterize - to characterize (someone or something) wrongly.

• Model - to plan or form after a pattern.

• Multi-disciplinary - combining or involving more than one discipline or field of study.

• National Academy of Sciences - a congressionally chartered organization that serves as part of the collective scientific national academy of the United States. 

• Objection - a reason or argument presented in opposition.

• Outcome - something that follows as a result or consequence.

• Overstep - exceed, transgress.

• Precipitation - a deposit on the earth of hail, mist, rain, sleet, or snow.

• Premature - happening, arriving, existing, or performed before the proper, usual, or intended time.

• Proffer - to present for acceptance.

• Projection - an estimate of future possibilities based on a current trend.

• Pronouncement - an authoritative announcement.

• Purview - the range or limit of authority, competence, responsibility, concern, or intention.

• Reference Manual on Scientific Evidence, Fourth Edition - supports judges in managing cases involving complex scientific and technical evidence by describing the basic tenets of key scientific fields and by providing examples of cases in which that evidence has been used. 

• Rigorous - very strict.

• Robust - having or exhibiting strength or vigorous health.

• Sanctity - the quality or state of being holy or sacred.

• Specificity - sharing or being those properties of something that allow it to be referred to a particular category.

• Subject - one that is placed under authority or control.

• Substantive - involving matters of major or practical importance to all concerned.

• Supersede - to cause to be set aside.

• Tenet - a principle, belief, or doctrine generally held to be true.

• Time frame - a period of time especially with respect to some action or project.

• Unbiased - free from all prejudice and favoritism.

• Underlying - basic, fundamental.

• Unequivocal - leaving no doubt.

• Violation - infringement, transgression.

• Wrangling - an angry, noisy, or prolonged dispute or quarrel.