Attorney General Tong Leads Letter to Federal Judicial Center Strongly Opposing Removal of Climate Science from Judicial Manual

06/02/2026

(Hartford, CT) – Attorney General William Tong today led a coalition of 23 attorneys general, the Cities of New York and Chicago, and Harris County, Texas in a letter to the Federal Judicial Center (“FJC”) strongly opposing its decision to strike the chapter titled, Reference Guide on Climate Science, from the Fourth Edition of its Reference Manual on Scientific Evidence. The accurate, peer-reviewed guidance on climate science was removed in response to unfounded partisan pressure.

The FJC has published the Manual since 1994 as a critical resource to assist judges in considering scientific evidence. It has been cited by the U.S. Supreme Court and thousands of other federal and state judges over its three decades in circulation.

Prior to publication, each chapter of the Manual undergoes extensive peer-review over many months by the scientific community and by judges, who offer feedback that is then incorporated into the chapter. The Reference Guide on Climate Science chapter was treated no differently than any other chapter and was subjected to the same deliberate and thorough peer-review process. That process was thrown aside when the FJC decided, without any explanation or public process, to remove the chapter on climate science in response to partisan pressure.

“Such a guide is sorely needed as litigation involving climate science only grows in prevalence and urgency in our courts. Furthermore, the chapter’s removal does not change the scientific reality of climate change. As the U.S. Supreme Court acknowledged nearly twenty years ago, “[a] well-documented rise in global temperatures has coincided with a significant increase in the concentration of carbon dioxide in the atmosphere,” a causal connection between manmade greenhouse gases and global warming exists, and “the harms associated with climate change are serious and well recognized.” In light of this scientific fact, removing the climate science chapter only harms our judicial system, as judges and litigants are left without impartial, peer-reviewed information on complex and crucial scientific issues. This undermines the FJC’s statutory purpose ‘to further the development and adaptation of improved judicial administration in the courts of the United States’,” the letter states.

“Ignoring science does not change reality,” said Attorney General Tong. “Courts rely on this reference manual for accurate scientific information when issuing decisions of enormous importance to public health and safety and our environment. Connecticut is leading attorneys general across the country today in urging the Federal Judicial Center to stand for truth and facts against partisan interference.”

The coalition urges the FJC to reinstate the Reference Guidance on Climate Science chapter to its Manual.

Attorney General Tong led the attorneys general and chief legal officers of Arizona, California, Colorado, Delaware, District of Columbia, Hawaii, Illinois, Maine, Maryland, Massachusetts, Michigan, Minnesota, Nevada, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont, Virginia, Washington, Wisconsin, the Cities of New York and Chicago, and Harris County, Texas in sending today’s letter.

Special Assistant Attorney General Michael Holler, Assistant Attorney General Kaelah Smith, Assistant Attorney General William E. Dornbos and Deputy Associate Attorney General Matthew Levine, Chief of the Environment Section assisted the Attorney General in this matter.

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