A Huge Retraction, the Usual Playbook, and Reason for Optimism

The collapse of Kotz et al. was followed by predictable climate spin but also signs of a return to scientific integrity

Pick one.

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Some huge news dropped today that will reverberate through climate science and policy. Nature has finally retracted “The Economic Commitment of Climate Change,” by Kotz et al. (KLW24), more than 18 months after first learning that the paper was fatally flawed, with the authors acknowledging that its errors are “too substantial” for a correction.

It is not just the retraction that matters — that’s long overdue — but the reaction to the retraction, which indicates that while the old ways still have a grip on the climate discussion, things may be changing for the better.

Back in August, I explained the growing scandal around KLW24: It wasn’t just a fatally flawed paper, but a flawed paper that had taken on outsized influence in climate advocacy and policy.

Too Big to Fail

For instance, KLW24 was the second most featured climate paper by the media in all of 2024, according to Carbon Brief.

More importantly, KLW24 has been widely used in policy around the world to justify projections of catastrophic future climate impacts and as a basis for cost-benefit analyses of mitigation.

Notable examples include:

• U.S. Congressional Budget Office

• OECD

• World Bank

• UK Office for Budget Responsibility

Significantly, the Network for Greening the Financial System, a consortium comprised primarily of central banks around the world, adopted KLW24 as the basis for its “damage function” used by bank regulators to stress test monetary policies against climate risks.

Consequently, it is not an exaggeration to claim that KLW24 has a potential financial impact on just about everyone. Of note, the U.S. Federal Reserve withdrew from the NGFS on January 17, 2025.

Given its central importance in regulation of the global financial system, one might think that the retraction of KLW24 would result in immediate action by the NGFS to correct their flawed damage function. But no.

For its part, the NGFS responded to today’s retraction by asking users of its recommended damage function to note the retraction, and presumably, to just carry on:

The NGFS scenarios are not forecasts, but are accessible tools intended to illustrate plausible pathways. Users should be aware of the retraction of the Kotz et al. (2024) paper when interpreting and applying Phase V results . . .

Of course, given the problems with KLW24, the only proper interpretation and application here would be to ignore the NGFS Phase V results altogether.

Some responses to the retraction follow the longstanding admit-no-error-nothing-to-see here approach to scientific integrity that has become normalized among climate activists in the media and in academia.

For instance, the AP tells its readers — incorrectly — that the retraction is a nothingburger and instructs them to move along:

The authors of a study that examined climate change’s potential effect on the global economy said Wednesday that data errors led them to slightly overstate an expected drop in income over the next 25 years.

The researchers at Germany’s Potsdam Institute for Climate Impact Research, writing in the journal Nature in 2024, had forecast a 19% drop in global income by 2050. Their revised analysis puts the figure at 17%.

The AP quotes an economist who tells us the paper’s results are correct, regardless the paper’s flaws:

Gernot Wagner, a climate economist at Columbia Business School who wasn’t involved with the research, said the thrust of the Potsdam Institute’s work remains the same “no matter which part of the range the true figure will be.”

In sharp contrast, and in a very pleasant surprise, the New York Times does much better, giving some hope that journalism may be returning to the center of the climate beat.

The Times cites some of the critics of KLW24.

For instance, Christof Schötz (who, interestingly, happens to be a colleague of the authors of KLW24 at the Potsdam Institute for Climate Impact Research) pulls no punches with his accurate portrayal of KLW24:

The paper does not provide additional evidence of economic damages from climate change, nor can it serve as a basis for reliable future projections.

The NYT also cites Lint Barrage, chair of energy and climate economics at ETH Zurich, who offers an important warning, and not just to the authors of KLW24, but more broadly to the climate research community:

It can feel sometimes, depending on the audience, that there’s an expectation of finding large estimates. If your goal is to try to make the case for climate change, you have crossed the line from scientist to activist, and why would the public trust you?

Well said.

The Times ends with another surprise: A nod to a view that THB readers will readily recognize — climate realism and energy pragmatism:

As one remedy, some researchers recommend not trying to do so much in the first place. Noah Kaufman, a senior research scholar at Columbia University’s Center on Global Energy Policy who worked in the Biden White House, believes studying specific questions — like how to decarbonize while keeping electricity affordable — is more useful than projecting macroeconomic impacts decades down the road.

“There are just a lot of examples in the world where we do recognize that there are large risks, but we don’t pretend we can optimize our response to them,” Mr. Kaufman said. “We just try to avoid them in a reasonable way.”

Amen.

Unfortunately, none of the coverage I've seen has credited Gregory Hopper, of the Bank Policy Institute, who was the first person I am aware of to identify flaws in KLW24 and bring that to the attention of the editors at Nature and the paper’s authors. Honest brokering is indeed a group effort and good results don’t always result in proper credit — But well done Greg!

Let’s watch to see how other policy organizations who leaned heavily on KLW24 choose to respond (or not) to the retraction. Meantime, let’s all work to ensure that climate science and policy are each self-correcting, and perhaps somewhat more efficiently going forward.

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