This Saturday, June 23, marks the 30th anniversary of what – from the standpoint of an ever-shrinking cadre of die-hard climate science contrarians – might be considered a “date that will live in infamy.”*

It was a sultry day in the nation’s capital when then-NASA climate scientist James Hansen delivered testimony on human-caused warming. He cautioned, as the New York Times reported with a page-one headline, that “Global warming has begun”.

After three decades of constant scrutiny, analysis, and re-analysis, this month’s “This is not Cool” video by Peter Sinclair asks a handful of climate scientists how Hansen’s testimony has stood-up.

Hansen “got it right,” says scientist Stefan Rahmstorf of the Potsdam Institute in Germany. “Amazing … remarkably prescient when it comes to the predictions he made decades ago and how it’s played-out,” says Penn State’s Michael Mann. He pointed to an “eerie match” between Hansen’s forecasts and actual observed warming in the succeeding decades.

Hansen in that 1988 congressional testimony nailed it, adds Texas A&M scientist Andrew Dessler. “You could have reached an alternative conclusion” based on the science at that time, he says, pointing to the 1990 IPCC conclusion that the observed warming at that point was consistent with global warming evidence, but also with natural variability.

“He was kind of out on a limb on one end of how you could read the data,” Dessler continued. “But it turned out he was right.”

That’s a view shared in the video also by climate scientists Eric Rignot of the NASA Jet Propulsion Laboratory and Zeke Hausfather of the University of California Berkeley. Lawrence Livermore National Laboratory’s Ben Santer says the mounting evidence since Hansen’s 1988 testimony clearly shows that natural variability alone “can’t come anywhere close” to causing the actual human-caused warming Hansen had projected.

*Due thanks and appreciation to President Franklin D. Roosevelt for that term as he applied it on December 8, 1941, to the previous day’s attack on Pearl Harbor.