“All of these predictions made by the United Nations and many others, often for bad reasons, were wrong.”

The predictions came true, and scientists checked. A peer-reviewed study in Geophysical Research Letters (Hausfather et al., 2020) systematically evaluated climate model projections published between 1970 and 2007 and found they were "skillful" in predicting actual subsequent warming, with no evidence that models systematically overestimated warming. NASA highlighted the study as confirmation that "climate models are getting future warming projections right."

Reality has kept pace with, and sometimes outrun, the projections. 2024 was the warmest year in the global temperature record, and Europe has warmed at twice the global average since the 1980s, according to the EU's Copernicus climate service. The IPCC, whose assessments undergo years of open review by thousands of scientists, concluded human emissions have "unequivocally caused global warming."

In September 2025, the National Academies of Sciences reviewed the full evidentiary record and concluded the 2009 finding that greenhouse gases threaten human health "was accurate, has stood the test of time, and is now reinforced by even stronger evidence." Those findings it called "beyond scientific dispute." The science Trump dismissed as exaggerated has only grown stronger with each passing decade of observation.

"Climate models published over the past five decades were skillful in predicting subsequent global mean surface temperature changes." — Hausfather et al., Geophysical Research Letters (2020), as published by NASA GISS