Did the authors of the Energy Department’s controversial 2025 climate report confuse two layers of the Earth’s atmosphere, and then use faulty analysis to question evidence of anthropogenic climate change? That is the extraordinary suggestion in a recent paper by five climate scientists published in the journal Earth’s Future.
Earlier this year, at a panel discussion about the Energy Department report, one of the authors exhibited a previously unpublished figure. It showed a dramatic discrepancy between predicted and observed temperatures in the tropical lower stratosphere—the second layer of the Earth’s atmosphere—and was used to support the claim that “models fail in the upper atmosphere.”
Benjamin Santer, the lead author of the Earth’s Future article, said the figure was wrong, and appeared to show observations from the troposphere, the lowest layer of the Earth’s atmosphere, instead of the stratosphere.
Santer and his Earth’s Future coauthors say this echoed a similar, and similarly inaccurate, argument in the Energy Department report, which they thought may have been based on this flawed analysis. They warn that until the Energy Department report is corrected or retracted it “will continue to misinform policymakers and the public about the reality of human effects on climate.”
The Bulletin contacted all five of the Climate Working Group members who wrote the 2025 report. Ross McKitrick, a Canadian economist, said the mistake in the unpublished chart stemmed from a coding error. John Christy, a climate scientist at the University of Alabama, said the figure was not relied on for the Climate Working Group report.
When asked if they had any plans to correct, clarify, or respond to this paper, or to any of the other errors and misrepresentations that other scientists have identified in the 2025 report, McKitrick said that the group has been disbanded and barred from publishing a revised version of the document or any other response to their critics.
The unrevised and uncorrected report is still circulating and can be used to propose or set policy in the United States.
He says the Climate Working Group members are caught between a rock and a hard place: Their report was thoroughly dissected and criticized by dozens of scientists, and while they say they have addressed those concerns in a revised version, they also contend they are unable to publish without violating a court order that ruled the group’s work illegal. As a result of a lawsuit filed by environmental advocacy groups, a judge found that the Energy Department and the Climate Working Group violated the law by not adhering to transparency rules and ordered the release of roughly 100,000 pages of emails and other documents related to the group’s work.
“Blame the people who brought the lawsuit against the DOE for the lack of response to date,” Judith Curry, a climate scientist and professor emerita at the Georgia Institute of Technology, told the Bulletin in an email.
The other Climate Working Group members—Steven Koonin, who presented the unpublished chart, and Roy Spencer—did not respond to requests for comment. The Energy Department also did not respond when contacted by the Bulletin for comment.
The continuing controversy over the report highlights the ongoing conflict between climate scientists who say their research is being misrepresented, and the Trump administration, which tried to draw on its own hand-picked set of skeptics to justify rolling back environmental regulations. Meanwhile, the unrevised and uncorrected report is still circulating and can be used to propose or set policy in the United States.
The Climate Working Group saga began in the spring of 2025, when Energy Secretary Chris Wright asked four scientists and one economist, all widely recognized as climate contrarians, to write a report that “critically review[s] the current state of climate science.” Emails released as part of the lawsuit appear to show that the group sought to provide scientific justification for the Environmental Protection Agency’s repeal of the endangerment finding—the legal basis for regulating greenhouse gases under the Clean Air Act. The endangerment finding asserted that rising atmospheric concentrations of six greenhouse gases, including carbon dioxide and methane, pose a risk to public health and future generations.
In April 2025, Roy Spencer, a meteorologist and climate scientist at the University of Alabama, advised his colleagues not to get too “mired in the technical details” at the expense of explaining how it will impact “eventual policy decisions related to the Endangerment Finding.” A few days later, he added, “About all I can hope is that what we write will provide sufficient ‘reasonable scientific doubt’…to call into question the original reasoning for the EPA Administrator’s decision that CO2 presents a threat to human health and welfare.”
Their report, “A Critical Review of Impacts of Greenhouse Gas Emissions on the U.S. Climate,” was published on July 29. The EPA issued its proposal to rescind the endangerment finding, which extensively cited an early version of the Climate Working Group report, on the same day.
In August, the Environmental Defense Fund and the Union of Concerned Scientists sued the Trump administration for tasking what it described as a secretive and one-sided group of experts with writing a report to inform federal policymaking, which it said was a violation of the Federal Advisory Committee Act.
In early September, more than 85 climate experts published a critical review of the Energy Department report, citing dozens of examples of cherry-picking, selective citation, and scientific misrepresentation.
Ironically, the Climate Working Group likely foresaw many of these criticisms in advance. As emails between members of the group reveal, during the editing process, Steven Koonin, a physicist and former chief scientist at BP and undersecretary for science in Obama’s Energy Department, now a fellow at Stanford’s Hoover Institution, asked Microsoft Copilot to review the draft for scientific accuracy and potential bias. The AI tool flagged numerous issues including “selective emphasis,” “outdated or narrow sourcing,” “selective citation,” “cherry-picked” evidence, “interpretive bias,” and “interpretive overreach.” To this critique, climatologist Judith Curry responded, “This is amazing, far better than what we would get from ‘real’ scientists.” At other points, the authors seemed frustrated that the LLMs they queried seemed to give greater weight to papers and voices representing the climate consensus than climate contrarians.
Around the same time, Secretary Wright informed the Climate Working Group that their services were no longer needed. The Trump administration then argued in court that the environmental groups’ lawsuit was moot because the Climate Working Group had been dissolved—an argument US district court judge William Young did not buy. In January 2026, he determined the Energy Department had violated the Federal Advisory Committee Act.
In February, the EPA officially repealed the endangerment finding, although notably without relying on the beleaguered Climate Working Group report.
So why are climate scientists still focused on a year-old report that has already been extensively criticized?
The main reason, given at the top of the Earth’s Future article, is that this report continues to inform policymakers and the public about the causes and consequences of anthropogenic climate change.
Although the judge found the Climate Working Group violated the law, he stopped short of ordering the Energy Department to strike their report from the federal record, as the environmental groups suing the administration had asked. That means that, although EPA chose to sidestep “scientific controversies” entirely, the agency could have cited it as evidence in its final repeal of the endangerment finding. Earlier this year, a group of Republican attorneys general did cite the report when demanding the Federal Judicial Center strike the chapter on climate science from a scientific reference manual for judges. So did Florida’s “Department of Government Efficiency,” which railed against cities and counties “squandering millions in virtue-signaling about a so-called climate crisis” in a report that cites the Energy Department climate report extensively.
The second reason is more personal. The Climate Working Group cast doubt on decades of research into and evidence of human-caused climate change, while citing work by Santer and others to support their conclusions. But Santer says the paper referenced provides “some of the most compelling scientific evidence to date of a human fingerprint on atmospheric temperature.”
“Imagine how it feels to have your life’s work incorrectly dismissed in an official government report—a report issued by the same agency you spent 30 years working for,” Santer told the Bulletin. “It does not feel good.”
“Imagine how it feels to have your life’s work incorrectly dismissed … by the same agency you spent 30 years working for. It does not feel good.”
— Benjamin Santer, retired Lawrence Livermore National Laboratory atmospheric scientist
To fully understand the “human fingerprint,” issue in question—in other words, evidence of anthropogenic climate change—requires an abbreviated climate science history lesson.
In 1967, Syukuro Manabe and Richard Wetherald published what has been described as “arguably the greatest climate-science paper of all time.” Using a pioneering climate model, the scientists not only estimated how much warming would occur if atmospheric carbon dioxide levels were doubled—they also predicted that rising carbon dioxide levels would warm the troposphere (the lowest layer of the Earth’s atmosphere) while cooling the stratosphere (the layer above the troposphere). The reason this happens is essentially because of the greenhouse effect: carbon dioxide prevents heat radiated out from the Earth from escaping into space, warming the Earth’s surface, while simultaneously reflecting more of the incoming heat from solar radiation back into space, cooling the stratosphere.
Manabe and Wetherald’s paper laid the groundwork for the field of climate fingerprinting, which seeks to attribute changes in the Earth’s climate to either human or natural causes. Subsequent decades of research—more advanced modeling as well as observations (measurements from weather balloons and satellites)—have generally confirmed Manabe and Wetherald’s predictions over 50 years ago, and scientists like Santer have confidently attributed these trends to human activity, specifically carbon dioxide emissions from burning fossil fuels.
However, in the section of the Energy Department report on “stratospheric cooling,” the Climate Working Group dismissed decades of research. “A combination of tropospheric warming and stratospheric cooling is a commonly cited ‘fingerprint’ of anthropogenic climate change,” the group wrote. “Stratospheric warming since 2000 coincides with continued surface and tropospheric warming, a pattern that is not found in climate model simulations and is not apparently consistent with the anthropogenic fingerprint.”
Santer and other climate scientists say this statement is wrong for several reasons. As they wrote in their rebuttal last year, the middle and upper stratosphere has been cooling since 1979 (when satellite measurements first became available) to the present day; the lower stratosphere cooled from 1979 to 2000 and then saw “muted trends” (neither strong warming nor cooling) since 2000.
But there’s also a simple explanation for why the lower stratosphere has stopped cooling or even begun to warm slightly since 2000: ozone. Like carbon dioxide, ozone is greenhouse gas, meaning it traps heat radiating out from the Earth’s surface and reflects heat from the sun. The widespread use of chlorofluorocarbons in aerosol sprays, refrigerants, solvents, and other applications depleted the amount of ozone in the atmosphere in the latter half of the 20th century, sparking global fears of increased cancer risk (ozone blocks many of the sun’s harmful ultraviolet rays), as well as cooling the stratosphere. When those chemicals were phased out as a result of the Montreal Protocol, the ozone layer stabilized in the 1990s and began recovering in the early aughts. More ozone meant that the lower stratosphere stopped cooling as quickly, and maybe even warmed slightly.
In their report, the Climate Working Group authors quote from a 2018 paper that found the lower stratosphere began warming in the 21st century, but as Santer and others have pointed out, they omit the part of the sentence that explains this is consistent with ozone recovery.
The authors then conflate this warming in the lower stratosphere with warming across the entire stratosphere and used that to suggest that climate models are wrong and to question evidence of anthropogenic climate change.
At least one internal reviewer, prepublication, also pointed out that this section of the report was misleading, cherry picks data, and takes it out of context. “This section should be removed or amended to note that stratospheric temperatures are influenced by multiple factors and that a comprehensive analysis of stratospheric temprature [sic] trends is fully consistent with those projected under climate warming scenarios,” they wrote.
The Climate Working Group made minor tweaks to the text in response to this and other queries, but did not address the substance of this critique when they had the opportunity.
“To the extent we were unclear about the distinction between the lower stratosphere and the upper (or entire) stratosphere it is a fair criticism and our revision goes into detail about the differences,” McKitrick wrote in emailed comments to the Bulletin.
Even though the Climate Working Group has been officially dissolved, the members have continued to discuss and promote their report. At a February event organized by the Civitas Institute at the University of Texas, John Christy, Steven Koonin, and Ross McKitrick presented their findings on extreme weather, climate models, and how climate change could impact economic growth. Andrew Dessler, a climate scientist at Texas A&M who co-led the scientific rebuttal to their report last year (and is a coauthor on the Earth’s Future paper), responded to each of their presentations.
When it was Koonin’s turn to discuss climate models, he doubled down on the claim that “Models fail in the upper atmosphere.” To illustrate this point, he exhibited a chart that showed a rough bell curve of climate models that almost all predicted cooling in the tropical lower stratosphere between 2000 – 2025, and then a bright red line far outside the mean model prediction, which was supposed to represent the actual observations. As the caption explained, “About ¾ of the models…predict continued cooling, whereas observations clearly show warming.”
The authors of the Earth’s Future paper inferred that this chart may have been the basis for the Climate Working Group’s claim that the stratosphere has warmed since 2000, contrary to what models predicted.
The only problem is that the chart has no basis in reality, according to critics. As Santer and his coauthors write in the Earth’s Future paper, they were unable to replicate the observations from the figure Koonin showed. Although they can’t be sure where those observations came from, they wrote that they “appear to be from the troposphere rather than the lower stratosphere.” If that were true, it would be an extraordinary and embarrassing mix-up.
John Christy later confirmed to Dessler that the observations in Koonin’s figure were incorrect, according to the authors of the Earth’s Future paper, but did not clarify how the mistake happened. In an email to the Bulletin, McKitrick said the mistake was due to a coding error and shared a corrected version of the unpublished chart—which still shows observations that are slightly warmer than model predictions, but nowhere near as drastic a difference as the original.
Both McKitrick and Christy expressed outrage that neither the authors nor the publisher of the Earth’s Future article gave them the opportunity to respond to criticism. Both also reiterated that what was published in July 2025 was what they describe as a draft report, although nothing in the press release, the energy.gov page where the report is linked, or the report itself indicates that it is merely a draft. In fact, the preface says that they submitted a draft for internal review in May, and they thank “a team of anonymous DOE and national lab reviewers whose input helped improve the final report.”
McKitrick and Christy say that they’ve gone over all of the comments in the rebuttal led by Dessler and Robert Kopp and have prepared a response and revised report, but are unable to publish anything.
“Unfortunately our group was disbanded due to the FACA lawsuit and we were forbidden from publishing a revised version or even our response material: we are still under that constraint and the problem remains unresolved,” McKitrick wrote.
While the working group has ceased to exist, there does not appear to be any prohibition on individual members from discussing or publishing on the issue either individually or collectively. In the September letter dissolving the group, Secretary Wright thanked them for challenging climate orthodoxies and starting a “much-needed debate in this area,” concluding: “Each of you remains free, as always, to continue engaging in that debate.”
Shortly after, Curry told E&E News that the members of the group would continue working outside the government to revise their report.
But McKitrick said that the Energy Department has since told them that they “cannot publish something as the ‘Climate Working Group’ or under any group name that might suggest to the court that we are still functioning as that same entity.”
McKitrick called it “a scientific disservice” when journals publish an “ambush attack” without allowing the other side to respond in print. “People end up talking past each other and you only get one side of the story, which doesn’t advance knowledge,” he said.
For his part, Santer said he would welcome a response to the Earth’s Future paper. Santer also reiterated that the problem is not just that the Climate Working Group made mistakes, but that they have failed to correct those mistakes.
“If, as a scientist, you get things wrong in an official government report—or in a presentation, in an open public presentation that’s up on YouTube—you can either set the record straight or not,” he said. “They’ve chosen not to set the record straight.”
