Twenty years ago, on this day,
“On 6 December 2005, in a presentation to the American Geophysical Union (AGU), James Hansen stated that, “we are on the precipice of climate system tipping points beyond which there is no redemption” (Hansen, 2005, p. 8). Hansen’s warning helped initiate a tipping point trend in climate change communication that was quickly reflected in public debate. These warnings were front page news by January 2006, with The Washington Post reporting that, “[t]his ‘tipping point’ scenario has begun to consume many prominent researchers in the United States and abroad…” (Eilperin, 2006, p. A01).”

The tipping point trend in climate change communication – ScienceDirect
See also Bowen Censoring Science 1 to 6
The amount of carbon dioxide in the air was 380ppm. As of 2025, when this post was published, it is 430ppm. This matters because the more carbon dioxide in the air, the more heat gets trapped. The more heat, the more extreme weather events. You can make it more complicated than that if you want, but really, it’s not. Fwiw, I have a tattoo of the Keeling Curve on my left forearm.
The broader context was that James Hansen had been getting in trouble with asshole Republican administrations since 1981, when a front page story on the New York Times had led to a research grant already given being withdrawn and people losing their jobs. The George HW Bush administration had also tried to sideline/silence Hansen in the key period 1989-1992. And on and on it went.
The specific context was HW’s dumb son, “Dubya” was nominally President, but you gotta assume a lot of the direction was coming from Dick Cheney. By this time the US was having to contend with the fact that the UN process, which it thought it had rendered pointless by withdrawing from Kyoto negotiations, was “back on track” (it’s all relative) and there would be more fights to come about this.
What I think we can learn from this – Hansen is worth listening to. It’s scary af.
What happened next – Hansen took (enforced) retirement. GISS got slaughtered in 2025. The emissions kept climbing, and the Republicans stopped pretending to be anything other than devastation-bots.
What do you think? Does this pass the ‘so what?’ threshold? Have I got facts wrong? Interpretation wrong? Please do comment on this post, unless you are a denialist, obvs.
Also on this day:
December 6, 2005 – CCS is our only hope, says Chief Scientist….
December 6, 2006- Turns out 0.1% of a Very BIG NUMBER is … quite a lot…
December 6, 2018 – Macron scraps a fuel tax because of protests – All Our Yesterdays


