San Antonio Express-News (Sunday)
Why climate skepticism persists despite the mounting evidence
WASHINGTON — Jim Walzel doesn’t fit the profile of a climate denier.
He’s a chemical engineer from Houston who made his money as a pipeline executive. He points to his COVID-19 vaccination card as proof he trusts science. He says he has little doubt that fossil fuels are warming the planet.
But he’s not convinced climate change will have cataclysmic consequences.
“I wouldn’t call myself a denier, but I am skeptical about the gravity of the thing,” said Walzel, who is 84. “I’m trying to look at the facts and say, ‘What’s the deal here?’ ”
Walzel’s views open a window on why climate skepticism persists, despite mounting evidence that global warming poses a serious threat to the planet and is already doing serious damage.
It’s a strain of thought grounded in the work of a small cadre of scientists who focus on uncertainties within climate science.
Those scientists do not question the fundamental notion that greenhouse gas emissions are raising global temperatures. Rather, they dispute that it will end in catastrophe. Sometimes dismissed as kooks or contrarians, they continue to find followers among people such as Walzel, who believe that if the world is going to pivot from fossil fuels to renewables in a matter of decades, we’d better be certain about the science.
NASA says 97 percent of published climate scientists agree that man-made carbon emissions have caused the planet to warm
over the past century. Climate skeptics — or realists, as they prefer to be called — home in on inconsistencies or contradictions within that consensus.
For instance, a recent report by the U.N. International Panel on Climate Change said planetary warming had reached the stage of a “code red for humanity.” But in the 4,000-page study, skeptics note, the term “low confidence” — jargon for findings where there is conflicting evidence — occurs almost 1,400 times.
The term “likely” — which could mean a degree of certainty as low as 66 percent — appears thousands of times.
When you add up that uncertainty, it suggests that climate
science has a long way to go, said Steve Koonin, a physicist who served as undersecretary of science at the U.S. Energy Department during the Obama administration.
Now director of the Center for Urban Science and Progress at New York University, Koonin published a book this year titled “Unsettled: What Climate Science Tells Us, What It Doesn’t, and Why It Matters.”
“We should be making societal decisions in a fully informed way, and there are things in the (U.N.) reports that contradict the narrative and nobody ever talks about them,” Koonin said. “I’ve had scientists say to me, ‘You’re right, but I wouldn’t dare say it.’ ”
Degrees of doubt
Climate scientists acknowledge the uncertainties but say there is plenty of well-documented evidence that climate change and its dire consequences are not only real but already upon us.
“You don’t need to agree with all the details to recognize there is a profound need to change the way we emit greenhouse gases into the atmosphere,” said Chris Field, director of Stanford University’s Woods Institute for the Environment.
In Koonin’s view, there are too many open questions to warrant that level of confidence.
Among them: the rate of ice melt in the Arctic. While polar ice is melting faster than it did in the 1990s, historical data indicate it’s occurring at the same pace as during the 1940s.
Another unsettled question is whether climate change is causing more intense hurricanes. The latest U.N. report said Category 3 or higher storms have “likely” — not definitely — increased in intensity since 1980.
In those and other cases, the uncertainty stems from the relatively short period in which climate data has been collected. Weather satellites weren’t launched into orbit until the 1960s. So scientists who track climate over centuries must rely on sometimes-murky historical records.
Koonin says scientists downplay those uncertainties in the belief that talking freely about the unknown would fuel public skepticism when the world needs political agreement to act on climate change.
What sounds like a conspiracy theory stems in part from comments in 1989 by Stephen Schneider, the late Stanford University professor and pioneer in climate science.
In a magazine interview, Schneider described a “double ethical bind” that required scientists to “offer up scary scenarios, make simplified, dramatic statements and make little mention of any doubts we might have” in order to focus public attention on the dangers of climate change.
Skeptics also point to a 1988 appearance before Congress by climate scientist James Hansen, who had traveled to Washington during a historic heat wave. Wiping sweat from his forehead, Hansen proclaimed, “The greenhouse effect has been detected,
and it is changing our climate now.”
Climate modeling, however, wasn’t nearly as advanced then as it is now, and other scientists took issue with what they viewed as a clever piece of stagecraft by Hansen that overstated their findings, said Deborah Coen, a science historian at Yale University.
“They believed he had compromised his integrity and their integrity,” she said.
The year after Hansen’s appearance, Exxon Mobil, ConocoPhillips, Chevron and other oil companies formed the Global Climate Coalition to challenge findings that human activity caused global warming and to campaign against regulation of greenhouse gas emissions.
A number of prominent scientists, including physicist Frederick Seitz, former president of the National Academy of Sciences, and theoretical physicist Freeman Dyson questioned whether global warming was the emergency that climate scientists portrayed.
“The skeptics kind of forced a lot of climate scientists to back off,” Coen said.
‘Nothing to be gained’
Eventually, mounting evidence of climate change and its effects made outright denial untenable. To question the finer points of climate theory risked scorn, ridicule and isolation.
Walzel, retired president of the now-defunct pipeline company Houston Natural Gas, knows the feeling.
Although not a household name, he is prominent in business and philanthropic circles. He serves on the boards of charities, and in his spare time he reads about climate change — his current stack is nine books tall.
But it’s not a subject Walzel discusses casually. He is reluctant to raise the issue outside a small circle of like-minded friends. “There would be nothing to be gained from it,” he said.
That sort of polarization has emerged within the scientific community as well. Matthew Hersch, a science history professor
at Harvard University, took issue with this reporter’s description of scientists such as Koonin as “seemingly well-reasoned skeptics.”
“Generally speaking, I would not call a person inclined to ignore known, catastrophic dangers because they are ‘decades away’ to be ‘well-reasoned,’ especially if those dangers are already manifest,” Hersch said by email. “That seems to be a simple case of wishing for something not to be true that is.”
‘Ammunition to the deniers’
Koonin entered the climate debate in 2014 when the American Physical Society asked him to lead an effort to review its
statement on climate change. A number of physicists had objected to the description of the evidence for global warming as “incontrovertible.”
Until then, he said, he accepted climate science as dogma. But when he assembled a group of six climate scientists in Brooklyn, he realized they could agree that human activity was causing the planet to warm but not on much else.
“Is it going to be catastrophic? That’s where the discussion broke down,” he said. “I had a committee member say, ‘We can’t write about uncertainty because it will give ammunition to the deniers.’ ”
Koonin resigned from the
American Physical Society and wrote an op-ed in the Wall Street Journal asserting that climate science was not settled, making him a pariah within the scientific community.
Asked about Koonin’s claims regarding ice melt and hurricanes, Field, the Stanford climate scientist, did not directly contradict him. As to why ice sheets are melting at about the same rate as during the 1940s, Field said it was an “incredibly complicated” question and that “diverse interpretations” remain about how fast polar ice will melt and will cause sea levels to rise.
But he expressed exasperation with those who suggest that uncertainty on ice caps or other
details undermines the overall theory that climate change would be catastrophic.
“You don’t get featured in the New York Times for saying I agree with that guy,” Field said. “That’s not the culture of science. Science is based on finding flaws and new interpretations.”