Koonin became publicly involved in the policy debate about climate change starting with a
Wall Street Journal opinion piece in 2017, in which he floated the idea of a
red team/blue team exercise for climate science. In 2018, the
Environmental Protection Agency (EPA) under the leadership of
Scott Pruitt proposed a public debate on climate change to refute the 2017
Climate Science Special Report. According to a draft press release edited by Koonin and William Happer, Princeton physics professor and director of the
CO2 Coalition, they planned "red team"/blue team exercises to challenge the
scientific consensus on climate. The draft was never released, and the plans were not carried out. In 2019, the
Trump Administration proposed to create a "Presidential Committee on Climate Security" at the National Security Council that would conduct an "adversarial" review of the scientific consensus on climate change. Koonin was actively involved in recruiting others to be part of this review. The committee was scrapped in favor of an initiative not "subject to the same level of public disclosure as a formal advisory committee". Koonin is a coauthor of the July 23, 2025,
U.S. Department of Energy report,
A Critical Review of Impacts of Greenhouse Gas Emissions on the U.S. Climate that asserted that the danger from greenhouse gas emissions was exaggerated. In an interview with
The Free Press, Koonin claimed that "Ninety-five percent of the report is sourced from" the
United Nations Intergovernmental Panel on Climate Change (IPCC) report.The report has been criticized for cherry-picking and for highlighting uncertainties in order to downplay the impacts of climate change. Furthermore, numerous scientists whose work was cited by the report indicated that their work had been mischaracterized.
2014 Wall Street Journal commentary Koonin wrote a 2000-word essay, "Climate Science Is Not Settled," that was published in an issue of
The Wall Street Journal. The main points of the article were that: • the limits of climate measurement data make it hard to untangle the planet's response to human influences, from natural changes that are poorly understood. • The results of various climate models disagree with or contradict each other. • Press releases, summaries, headlines, and news stories often don't accurately reflect the consensus among scientists. • The science is not mature enough to make useful projections about the future of the climate, nor what effects past or future human actions might have on it. In an article in
Slate, climate physicist
Raymond Pierrehumbert criticized Koonin's essay as "a litany of discredited arguments" with "nuggets of truth ... buried beneath a rubble of false or misleading claims from the standard climate skeptics' canon."
2021 book Unsettled In 2021, Koonin published the book ''Unsettled: What Climate Science Tells Us, What It Doesn't, and Why It Matters''. In a review in
Scientific American, economist
Gary Yohe wrote that Koonin "falsely suggest[s] that we don't understand the risks well enough to take action": Physicist
Mark Boslough, a former student of Koonin, posted a critical review at
Yale Climate Connections. He stated that "Koonin makes use of an old strawman concocted by opponents of climate science in the 1990s to create an illusion of arrogant scientists, biased media, and lying politicians – making them easier to attack." Nonprofit organization
Inside Climate News reported that climate scientists call Koonin's conclusions "fatally out of date ... and based on the 2013 physical science report of the
Intergovernmental Panel on Climate Change (IPCC)." Mark P. Mills, a senior fellow at the
Manhattan Institute, a conservative think tank, and faculty fellow at
Northwestern University’s McCormick School of Engineering and Applied Science, lauded the book in
The Wall Street Journal as "rebut[ing] much of the dominant political narrative". Twelve scientists analyzed Mills's arguments and said that he merely repeated Koonin's incorrect and misleading claims. On August 21, 2023, an interview with Koonin was released via the Stanford University Hoover Institution video series, Uncommon Knowledge with Peter Robinson. ==Publications==