Dessler “Unhinged” at CO2/Climate Optimism Report (“doomism” under siege)

By Robert Bradley Jr. -- September 11, 2025

“Personal character matters for scientific transparency and honesty. Andrew Dessler does not pass the temperament test in a field of unsettled causality and ambiguous data.”

The intellectual case for CO2/climate optimism in place of doomism and despair is straightforward. As neatly summarized by Steven Koonin (a ‘climate flat earther‘ to Andrew Dessler) in the Wall Street Journal:

• Elevated carbon-dioxide levels enhance plant growth, contributing to global greening and increased agricultural productivity.
• Complex climate models provide limited guidance on the climate’s response to rising carbon-dioxide levels. Overly sensitive models, often using extreme scenarios, have exaggerated future warming projections and consequences.
• Data aggregated over the continental U.S. show no significant longterm trends in most extreme weather events. Claims of more frequent or intense hurricanes, tornadoes, floods, and dryness in America aren’t supported by historical records.
• While global sea levels have risen about 8 inches since 1900, aggregate U.S. tide-gauge data don’t
  show the long-term acceleration expected from a warming globe.
• Natural climate variability, data limitations and model deficiencies complicate efforts to attribute specific climate changes or extreme events to human CO2 emissions.
• The use of the words “existential,” “crisis,” and “emergency” to describe the projected effects of human-caused warming on the U.S. economy finds scant support in the data.
• Overly aggressive policies aimed at reducing emissions could do more harm than good by hiking the cost of energy and degrading its reliability. Even the most ambitious reductions in U.S. emissions would have little direct effect on global emissions and an even smaller effect on climate trends.

But Andrew Dessler will have none of it. It is not simple–it is mind-numbingly complex and can only be explained voluminously. His rebuttal of Koonin et al. climate science report released by the U.S. Department of Energy, “A Critical Review of Impacts of Greenhouse Gas Emissions on the U.S. Climate,” begins:

Our comment on the DOE CWG report is done. It tips the scales at 439 pages, approx. 3x longer than the DOE report. This is related to Brandolini’s law: The amount of energy needed to refute bullshit is an order of magnitude bigger than that needed to produce it.

So the U.S. Department of Energy climate science report is “bullshit”? Let’s see what else Dessler has to say. In “The Merchants of Doubt are Back,” Dessler complains that the report was not worth his time to rebut (!). “When I read the DOE report,” he states, “I saw a document that does not respect science.”

In fact, I saw a document that makes a mockery of science. And I thought to myself, I cannot let this go without a response. So that’s why I’ve spent a huge amount of time over the last month (when I should have been working on my classes for the fall semester) putting this comment together.

Who is this irritable, arrogant (depressed?) fellow? Consider these quotations from Dessler’s past:

“If you’re pushing fossil fuels at this point, you’re anti-human.” (2022)

“Fossil fuels are shredding our democracy.” (2024)

Dessler is a climate alarmist on fire:

The worst-case scenarios of climate change are truly terrible, but even middle-of-the-road scenarios portend environmental change without precedent for human society.

If “some humans survive” is the only thing we care about, then climate change is a non-issue. I think it’s certain that “some” humans will survive almost any climate change. They may be living short, hard lives of poverty, but they’ll be alive.

Future humans, as they live in a climate dystopia: “I thought he cared about the environment”.

I find the path we’re on now — the rich world survives (if lucky), but abandons everyone else — to be morally problematic.

And this head-scratcher:

Hey assholes. We’ve been telling you for decades that this was going to happen if we didn’t reduce greenhouse gas emissions. You didn’t listen and now it’s all happening. We hope you’re happy. Enjoy the heatwaves, intense rainfall, sea level rise, ocean acidification, and many other things, you fucking morons.

Dessler likes to throw out those en masse who do not agree with him, even the discipline of climate economics.

In order to solve the climate problem, the first thing we need to do is ignore the economists.

Real Climate Science

Science into the unknown should be marked by humility. And climate science is just that. Note how the authors of the DOE science report responded to Angry Andy. Judith Curry is more than polite:

Before getting into specifics of the Dessler Report, a big bravo and kudos to Dessler et al., who are actually behaving like scientists with their rebuttal to the DOE report.   This is exactly the kind of response and dialogue that we hoped the DOE Report would stimulate. (update: in his media interviews, Dessler is sounding pretty unhinged, at this point he risks undoing the “good” from this report).

In “At Long Last, Clarity on Climate,” Steven E. Koonin gently addresses hair-on-fire Dessler:

Though scientists supporting the so-called consensus on climate change have organized several serious critiques, these at most add detail and nuance to our findings, without negating the report’s central points. They still merit response, which will form the next round in an overdue public debate on the effects of greenhouse-gas emissions.

In other words, let’s go back-and-forth with the debate over theory, data, and climate modeling. This is exactly what Dessler (and the Climategate/IPCC bunch) do not want. In their fire-ready-aim world, they go ad hominem and invoke argument-by-authority in the belief that the public will the CO2/climate optimists are shameless fossil-fuel stooges. Except they are not–and the public sees right through the multi-decade exaggerations of climate alarmism and forced energy transformation.

Conclusion

Dessler overstates his case so badly that he isolates himself, just like Michael “Climategate” Mann (“climate deniers, in general, are truly awful human beings”) and Joe Romm (he has called me a “sociopath”) have done to themselves. Dessler’s prima donna behavior is a surefire sign that this fellow is less a scientist than an activist shaping science with an agenda (an anti-capitalist agenda) in mind.

Personal character matters for scientific transparency and honesty. Andrew Dessler does not pass the temperament test in a field of unsettled causality and ambiguous data.

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[1] Remember what John Holdren said about Bjorn Lomborg’s paradigm busting The Skeptical Scientist: Measuring the True State of the World (515 pages; 2,930 footnotes)? Echoes of Dessler today:

That the responses of environmental scientists have conveyed anger … ought to be understandable. Lomborg’s performance careens far across the line that divides respectable even if controversial science from thoroughgoing and unrepentant incompetence. He has failed thoroughly to master his subject. He has committed, with appalling frequency and brazen abandon, exactly the kinds of mistakes and misrepresentations of which he accuses his adversaries. He has needlessly muddled public understanding and wasted immense amounts of the time of capable people who have had to take on the task of rebutting him. And he has done so at the particular intersection of science with public policy – environment and the human condition – where public and policy-maker confusion about the realities is more dangerous for the future of society than on any other science-and-policy question excepting, possibly, the dangers from weapons of mass destruction.