Contrarian climate assessment from U.S. government draws swift pushback | Science | AAAS
]Researchers say DOE report cherry-picks data to downplay threat of greenhouse gases
 U.S. Department of Energy Secretary Chris Wright handpicked the five contrarian scientists who authored a controversial new climate report.Tom Williams/CQ-Roll Call, Inc via Getty Images
The last assessment of the state of climate science from the United Nations’s Intergovernmental Panel on Climate Change (IPCC), published in its final form 2 years ago, was a monumental effort, with 721 volunteer scientists synthesizing all available published research. Yesterday, the Department of Energy (DOE) released its own climate assessment, as part of a campaign by the U.S. Environmental Protection Agency (EPA) to overturn its landmark endangerment finding from 2009, which found that burning fossil fuels endangers public health and established carbon dioxide as a pollutant EPA could regulate. But the DOE report—called A Critical Review of Impacts of Greenhouse Gas Emissions on the U.S. Climate—had fewer authors than IPCC’s: just five.
Handpicked by DOE Secretary Chris Wright, a fossil fuel entrepreneur, the authors are well known to climate scientists. Although the members of this Climate Working Group all hold scientific doctorates, they hold contrarian views on climate science that are out of step with the mainstream. The report, assembled in months, argues that some of the warming attributed to fossil fuel burning is instead driven by natural cycles or variability in the Sun, and that sea level rise has not been accelerating. Climate researchers say the authors cherry-picked evidence and highlighted uncertainties to achieve the net effect of downplaying the impacts of climate change. “This shows how far we have sunk,” says Naomi Oreskes, a historian of science at Harvard University. “Climate denial is now the official policy of the U.S. government.”
The report is far from comprehensive. Many of its arguments are common among critics of climate action, previously made online and in obscure journals. It amounts to a “law brief from attorneys defending their client, carbon dioxide,” said Andrew Dessler, a climate scientist at Texas A&M University, on Bluesky. “Their goal is not to weigh the evidence fairly but to build the strongest possible case for [carbon dioxide’s] innocence. This is a fundamental departure from the norms of science.”
In a blog post, Judith Curry, one of the authors and president of the Climate Forecast Applications Network, acknowledged the report couldn’t be comprehensive given the time constraints. “We selected topics that we judged to be of particular importance and relevance in the context of U.S. climate and energy policy deliberations,” she wrote. She also said the report was reviewed by eight scientists or administrators at DOE. And she hoped the report would redirect climate science “away from alarmism and advocacy.”
The authors of the report state they are open to comments and revision, and the test of that will come quickly. Already multiple scientists have said their work has been mischaracterized. Zeke Hausfather, a climate scientist at Stripe, noted in a Bluesky post that the report cited his influential study in 2020 showing the most extreme climate scenario sometimes used by modelers, based on emissions rising for many decades to come, no longer represents reality because emissions are close to plateauing. But the report said that finding undermined EPA’s projections of warming. “Their point is completely backwards,” Hausfather wrote, noting that Earth would still warm with lower emission scenarios. “My paper actually supports the EPA’s 2009 range of 1.8C to 4C warming by 2100.” And Richard Tol, a climate economist at the University of Sussex, wrote a blog post today noting the report mischaracterized his studies to suggest climate change could benefit poor countries, when the preponderance of evidence finds the opposite.
The report makes some points that mainstream climate scientists would acknowledge. It decries media hype and points out that global warming is not the only challenge facing humanity. It argues that rising carbon dioxide levels can benefit some plants—a known “carbon fertilization” effect. It says the extreme emissions scenario should not be used to forecast climate impacts, a course correction the field has rapidly made. It points out that the latest generation of climate models run too hot, and they should be used with care—something climate scientists have also done. And it says that because the models run hot, the future rate of warming should be estimated instead using constraints from observed warming levels and past climates, among other factors—a step IPCC already took in its last report.
The report also highlights real research questions. It brings up the fact that more sunlight has been reaching the ground over the past 2 decades than before, accelerating warming. And it notes that, although declining air pollution is certainly part of the reason for this trend, diminishing cloud cover is as well—and, as Science covered late last year, the pressing question is now whether these changes are a feedback from warming. The report also attacks so-called extreme event attribution—efforts to quantify the contribution of global warming to extreme weather—as unreliable. Although the critiques may not be identical, mainstream climate scientists have also pushed for more rigor in attribution studies.
Far more often the report follows a familiar pattern, wrote Ben Sanderson, a climate scientist at CICERO, a Norwegian climate research institute, on Bluesky. “Establish a contrarian position, cherry pick evidence to support that position, then claim that this position is under-represented in climate literature.” In the case of global sea level rise, for example, it focuses on the noisy data from tide gauges, rather than the clear picture of accelerating sea level rise seen with satellite altimeters. The report, he writes, repeats the same cherry-picking in its discussion of agriculture, highlighting the carbon fertilization effect over the problems plants face with heat stress and drought, and in the regional extreme weather events it chooses to emphasize, focusing on events that are not increasing with warming.
In discussions online, climate scientists were still mulling what sort of response to make to the report. One option would be a full scientific breakdown, which could then be cited in eventual legal cases. But with such a report given the gloss of the U.S. government, they also need to make clear how much more comprehensive the assessments conducted by IPCC are, Sanderson said. “We can always strive to do better.” |
