The Federal Judicial Center has deleted the entire climate science chapter from its Reference Manual on Scientific Evidence, a nearly 2,000-page guide used by federal judges to understand complex scientific topics. The chapter, authored by researchers from Columbia University, is no longer available to judges presiding over climate-related litigation.

This action followed a letter from a group of Republican state attorneys who objected to the chapter's core conclusion that human activity drives climate change. They also contested its description of the Intergovernmental Panel on Climate Change as an "authoritative science body," a characterization they opposed based on a paper from a Canadian conservative think tank. The attorneys refused proposed revisions, demanding full removal.

The deletion leaves judges without this vetted scientific resource for climate cases. The move is particularly striking given that more than 99.9 percent of peer-reviewed research agrees on human-caused climate change. The manual's introduction by Supreme Court Justice Elena Kagan still references the now-deleted chapter, creating an internal contradiction. The full text of the removed chapter remains publicly accessible via RealClimate.