“Unsettled” Climate Science: So What?

An advance look at my review of Steve Koonin's Unsettled

Roger Pielke Jr.

Jul 5, 2022

Below is my review of Unsettled by Steve Koonin, which appears in the Summer 2022 issue of The New Atlantis (Update: Here is the link).

In a recent interview in New York Times Magazine, energy expert and polymath Vaclav Smil found himself being pressured by his interviewer to acknowledge that climate change was either a catastrophe or not a problem. The famously cantankerous Smil bristled at the framing:

“I cannot tell you that we don’t have a problem because we do have a problem. But I cannot tell you it’s the end of the world by next Monday because it is not the end of the world by next Monday. What’s the point of you pressing me to belong to one of these groups?”

For well over a decade, the American debate over climate change has largely been a battle between two extremes: those who view climate change apocalyptically, and those castigated as deniers of climate science. In institutions of science and in the mainstream media, we see the celebration of the catastrophists and the denigration of the deniers. Predictably, the categories map neatly onto the extremes of left-versus right politics. The most apt characterization of this polarized framing is as a kind of Manichean paranoia—a politics defined by the belief that the debate is really a battle of absolute good against absolute evil over the future of the world.

Manichean paranoia has a long history in America. In his famous 1964 essay, “The Paranoid Style in American Politics,” historian Richard Hofstadter argued that the paranoid person

“does not see social conflict as something to be mediated and compromised, in the manner of the working politician. Since what is at stake is always a conflict between absolute good and absolute evil, what is necessary is not compromise but the will to fight things out to a finish.”

Today, the Manichean politics of climate change play out on social media, where leading scientists, journalists, and other combatants seek, to borrow from Jonathan Haidt, “to shame or punish someone publicly while broadcasting one’s own virtue, brilliance, or tribal loyalties.” The incredibly fascinating, important, and nuanced issue of climate change has become an online team sport between the good guys (your side) and the bad guys (the other side).

The politics of Manichean paranoia, as I have elsewhere argued, have had a deeply pathological influence on the debate over climate science and policy. My own experiences—which include being attacked by the White House and investigated by Congress for publishing and communicating peer-reviewed research—are symptomatic of the pathology, but they are only small examples of how the debate seeks to force participants into one of two extreme camps. Smil is right to push back against this pressure, even if the resistance has so far been futile.

New York University physicist Steven Koonin had a fantastic opportunity to push back on the Manichean framing of the climate issue in his bestselling book Unsettled: What Climate Science Tells Us, What It Doesn’t, and Why It Matters, and to present an alternative, nuanced perspective largely missing from public debate. But after some early resistance, Koonin gives in to the Manichean politics, embracing the conventional, divisive framing. The response to the book has been predicable, with both supporters and opponents relishing the battle—combatants in a deeply polarized struggle have an existential need for their mirror image. Koonin’s book could have challenged the pathological politics of climate change. Instead, it reinforces them.

Koonin’s elevator pitch has him off to a good start: “Climate and energy are complex and nuanced subjects. Simplistic descriptions of ‘the problem’ or putative ‘solutions’ will not result in wise choices.” Koonin is, of course, correct. Any issue that combines the energy-producing and -consuming habits of almost eight billion people with the intricacies of the physics, biology, chemistry, and habitation of global systems is not going to be simple.

But from this call for recognizing complexity, Koonin arrives at his own simplistic conclusion:

The impact of human influences on the climate is too uncertain (and very likely too small) compared to the daunting amount of change required to actually achieve the goal of eliminating net global emissions by, say, 2075... . I would wait until the science becomes more settled... before embarking on a program to tax or regulate greenhouse gas emissions out of existence or to capture and store massive amounts of carbon dioxide from the atmosphere.

For Koonin, the settledness of the science is the fulcrum on which rests the pursuit of policies intended to decarbonize the global economy. Of course, placing the science of climate change at the center of climate politics privileges the expertise of physicists like Koonin and of his fiercest opponents. Indeed, the only thing on which Koonin and his opponents seem to agree is the centrality of science in the climate debate. Politics—how things get done in a world where people and nations have diverse wants and needs—becomes peripheral.

Science is the focus of Unsettled — Koonin devotes eleven chapters to explaining his views of it and only three to how society should respond. The imbalance may seem appropriate, if the settledness of science is the sole basis for policy. But for those of us who view science as one of many inputs into policy, the imbalance is a problem.

Consider, for example, Europe’s energy choices in response to Russia’s invasion of Ukraine. Europe’s longstanding reliance on fossil fuels from Russia has revealed geopolitical risks. As a result, the European Union is now focused on reducing its reliance on fossil fuels, including by expanding its nuclear-power production. There are good reasons to accelerate the decarbonization of Europe’s economy that have little to do with climate concerns. And yet both climate concerns and energy security can lead to similar outcomes.

Koonin engages none of this political complexity, making it easier for him to maintain his single-minded focus on climate science. But if we achieve net-zero emissions targets, it will be because we collectively find a way through the maze that is global geopolitics, not because everyone comes to agree that climate science is settled.

Koonin—a former scientist for BP and for President Obama’s Department of Energy—tells the story of how he came to doubt the settledness of climate science. In 2013, the American Physical Society asked him to review its existing statement on climate science, so he convened a meeting of a range of experts to examine the most current studies. He realized that the science on climate change was far less settled than he had previously thought. It was a “revelation,” he writes. But then the statement his group crafted was rejected by a larger committee. He received similar pushback from fellow scientists to a 2014 Wall Street Journal article he wrote to air his views. On a recent episode of Joe Rogan’s podcast, his anger and frustration are palpable:

“People would say things like, ‘we can’t say that, even if it’s true, because it gives ammunition to the deniers.’” The result was a feeling of being “increasingly dismayed at the public discussions of climate and energy.”

I have a great deal of sympathy for Koonin’s reaction. I have viewed the public treatment of climate science from the inside, as someone who for almost thirty years has produced peer-reviewed research in climate science and policy. I have seen my work filtered through the media, referenced in policy, and, most recently, cited in the latest assessment report of the Intergovernmental Panel on Climate Change (IPCC). And, like Koonin, I have seen my work celebrated by some, and spun, attacked, and delegitimized by others.

Koonin is absolutely correct that public representations of climate science often don’t square with consensus understandings of the scientific literature, such as those of the IPCC. To take a clear example: Most people are probably unaware that in 2021 there were fewer hurricane-strength tropical cyclones worldwide—that is, 37 hurricanes—than in any year since at least 1980. The IPCC has been consistent for decades in its conclusion that there is “low confidence” that we can discern any long-term trends of cyclone frequency and intensity. The panel has concluded much the same for floods, droughts, and tornadoes (although heat waves and extreme precipitation have increased). Yet, there remains ample public misperception promoted by the media and climate activists, including many scientists, that hurricanes, floods, and droughts have all become more common and more destructive. I understand Koonin’s frustrations.

He helpfully points out this widespread misperception in Unsettled, spending two chapters on extreme events, with a focus on storms and precipitation. “As for the media,” he writes, “pointing to hurricanes as an example of the ravages of human-caused climate change is at best unbecoming, and at worst plainly dishonest.” In his discussion with Rogan, Koonin explains that becoming more informed about hurricanes was a major factor in his thinking on climate science and policy. But it is difficult to disentangle his frustrations with the media from his concerns about climate science itself.

Admittedly, climate scientists are sometimes complicit in the misrepresentation of the science. Koonin takes particular issue with the treatment of hurricanes by the 2014 U.S. National Climate Assessment, which used a subset of data on hurricane intensity to suggest a conclusion at odds with a longer record using the same metric. Koonin is absolutely correct that the assessment’s authors cherry-picked data to convey a misleading impression (which he observes was corrected deep in the report’s appendix). However, an instance of cherry-picking, or even several, is not sufficient for impeaching “the science” itself, much less policy proposals that are based on far more than scientific claims alone.

Koonin’s recommended remedy for improving assessments is to create a so-called “red team” of experts to challenge assessment conclusions. Red-teaming means playing adversary, or devil’s advocate, to test the vulnerabilities of a strategy or system. It was originally an American preparedness practice in the Cold War, with the United States being the blue team. It’s an exercise that has been used in contexts such as national defense, cybersecurity, aviation, and pandemic preparedness. However, in the case of an issue like climate change that maps so perfectly onto left-versus-right politics, the creation of red teams runs the risk of simply institutionalizing the broader Manichean politics within the assessment process: Would you like Democratic or Republican climate science?

The design and implementation of effective science advice deserves much more careful attention. A far better approach for redesigning the assessment process would be to ensure ways to include dissent—for panels to represent a diversity of and even oppositional expert views. Because empanelment processes can be opaque and out of sight, assessments often run the risk of falling into groupthink through the selection of likeminded participants.

The larger political problem is that so many actors treat assessment reports as sacred texts. Koonin points to a failed but nonetheless troubling 2019 effort by more than a dozen Democratic senators to legislate that no federal funds could be used, as the bill read, “to challenge the scientific consensus on climate change.” Similarly, recent Twitter guidelines prohibit ads that contradict the conclusions of the IPCC. Such efforts to use assessment reports to police claims about science could not be more wrongheaded. Koonin is on solid ground when rebuffing efforts to silence dissenting voices.

Assessment reports are not scripture conveying enduring truths. They are snapshots at a point in time of what a group of experts do and do not think they know based on a large and varied literature. Such assessments can be incredibly useful to non-experts, because they bring together a range of views on a complex body of knowledge. But the point of establishing a consensus view should not be to police dissent, or to discourage future research that may produce results challenging that consensus. Indeed, such challenges can reinforce the stature and importance of consensus understandings, and in some cases may lead to their evolution as new research is produced. The IPCC consensus process should be reformed in such a way that it can weather challenges to its legitimacy, which means that it should empower dissent and openness to critique.

Koonin’s “red team” proposal doesn’t address some of the key reasons climate assessments get off track and fail to represent the data and literature accurately. One such reason is politics. Consider the U.S. National Climate Assessment, mandated by Congress to produce a report every four years. This assessment is overseen by political appointees in the White House, which has long viewed the assessment as a resource for advocacy of the administration’s climate agenda. Unsurprisingly, the assessment has been used by Republican administrations to cast doubt on mainstream views of climate change and by Democratic administrations to dramatize its effects, as with the cherry-picked hurricane data Koonin identifies. No scientific assessment should be directly overseen by political appointees.

Climate assessments get off-track for more mundane reasons as well, like institutional inertia, career incentives, and knowledge “lock-in.” Consider, for example, the lock-in of outdated climate scenarios, which a colleague and I have identified in a 2021 paper. Climate research has been dominated by an extreme scenario of future carbon dioxide emissions that is no longer plausible. The IPCC has begun to accept that extreme climate scenarios are outdated, and yet the recent sixth assessment report still depends crucially on such scenarios. Reform of the panel is long overdue. After its fourth assessment report in 2007 was found to have some quality control issues, the InterAcademy Council conducted a review, and recommended a number of reforms. Newer IPCC reports since then would have benefited from careful attention to and implementation of these recommendations, which might have helped to prevent the lock-in of outdated scenarios.

Unfortunately, Koonin does not engage these issues— instead, he falls victim to the IPCC’s use of outdated scenarios himself. He makes the following contradictory claims, just two pages apart:

“The science is insufficient to make useful projections about how the climate will change over the coming decades, much less what effect our actions will have on it.”
“The net economic impact of human-induced climate change will be minimal through at least the end of this century.”

Obviously, if our science is insufficient to make useful projections of our actions on future climate, then that means we cannot say with any certainty that the economic effects of human-induced climate change will be minimal. The reason Koonin says they will be minimal is that he takes at face value a 2014 figure of projected climate change impacts on economic welfare—a figure summarizing various dated studies, some going as far back as 1994. After offering this old estimate of economic impacts, which does not factor in any other consequences of climate change, he presents his own back-of-the-envelope projection of future GDP growth, which then leads him to conclude with an air of certainty that “significant human-induced climate change would have negligible net economic impact on either the world or the US economies by the end of this century.”

In this instance, Koonin’s criticisms of others—cherry-picking, credulity, and failure to subject claims to informed critique—apply to his own cursory analysis.

And this brings us to how Koonin’s book has been received in the climate debate. It has been both welcomed and rejected, often at the same time. That is, Koonin’s opponents have welcomed Unsettled as another opportunity to contrast their virtue with his vice.

One review, published in Scientific American, starts by seeking, it seems, to impeach Koonin’s supposed political intentions and the lengths to which he is willing to go to undermine the progress of climate science:

“Koonin’s intervention into the debate about what to do about climate risks seems to be designed to subvert this progress in all respects by making distracting, irrelevant, misguided, misleading and unqualified statements about supposed uncertainties that he thinks scientists have buried under the rug.”

And a group of climate scientists, including IPCC contributors and members of the U.S. National Academy of Sciences, goes further, writing in the same outlet that Koonin is

“a crank who’s only taken seriously by far-right disinformation peddlers hungry for anything they can use to score political points. He’s just another denier trying to sell a book.”

In Manichean politics, there can be no legitimate differences of opinion or interpretation, only good and evil.

In 2014, when Koonin wrote the Wall Street Journal article that would eventually lead to this book, the newspaper’s editors gave the piece the title “Climate Science Is Not Settled.” At the time, Koonin expressed disapproval of the headline, telling a reporter, “I would have chosen something more nuanced.” His working title, as he remembered it, was “Climate Clarity.” But, he said, “I don’t have to sell newspapers.”

Vaclav Smil bristled when a New York Times reporter pressed him to adopt one extreme or the other in the climate debate. Koonin has taken a different path. His journey over the past decade, resulting in Unsettled, is a parable in the annals of the Manichean politics of climate. A different book with a different focus—perhaps titled Climate Clarity —would have been a better choice.

Roger Pielke, Jr. is professor of environmental studies at the University of Colorado Boulder and the author, most recently, of The Rightful Place of Science: Disasters & Climate Change (2018, orig. 2014). His newsletter is The Honest Broker.