NYU Physicist: Humans Haven't 'Broken the Climate'

Humans are "certainly influencing" the world's climate, but "the notion we've broken the climate is misplaced," Dr. Steven Koonin, who served as the chief scientist in former President Barack Obama's Energy Department, said Tuesday. 

"Human influences are growing as carbon dioxide in the atmosphere grows, but beyond the warming of about 2 degrees Fahrenheit over the last century, we don't see many impacts on severe weather events," the New York University physicist said on CNBC's "Squawk Box." "For example, heat waves are more uncommon today than they were in 1900 and they haven't gone up in 60 years."

Further, he said, there have been no "detectible human influences on hurricanes," and wildfires have declined by about 25% globally since 2003. 

"Despite the terrible fires we saw in California and Australia in 2020, (that year) was one of the least active global fire years on record," said Koonin. 

Koonin, a theoretical physicist who now serves as the director of NYU's Center for Urban Science and Progress, has outlined his viewpoint in his new book "Unsettled." He acknowledged Tuesday that his view on the climate has changed over the past 7 years after leaving the Obama administration. 

"About seven years ago, I had the opportunity to look more deeply into the science and in the intervening seven years I've come to believe that the science does not say what you think it says, to borrow a line from 'The Princess Bride,'" said Koonin. 

He added that everything in his book comes from official United Nations and U.S. government assessment reports, so his reporting is from "consensus science" that has not been brought into public or political discussion. 

Koonin's comments came a day after the Biden administration used its federal powers for the first time Monday to limit emissions by proposing a rule to phase out the use of hydrofluorocarbons, or HFCs, the common refrigerant used in air conditioners and refrigerators. 

The rule against the greenhouse gasses requires the U.S. to bring down production and imports of HFCs by 85% over the next 15 years, reports NBC News. The phaseout is expected to avert up to .5 degrees Celsious in global warming, according to the EPA. 

But Koonin said Monday that such change must take place slowly to make sure disruptions of the nation's energy system and society are not too damaging. 

"Energy pervades everything," he said. "We need to change it slowly to ensure the disruptions are not significant. You change the energy system by orthodonture, versus by tooth extraction."

Koonin added that there will be no effect on the world's climate if other countries don't take action. 

"If the U.S. were to go to zero (emissions) today it would still be only a 15% reduction in global emissions," said Koonin. "The developing world is growing and as (climate czar) John Kerry and the president have said, unless the rest of the world comes along, U.S. efforts are futile."

Koonin added that "hardly anybody reads the real reports" on climate change, so his book makes the information from those reports accessible to non-experts. 

"People can check what I say and if they find that what I'm saying is true, as I hope they will, they might be asking what else haven't we been told about the climate?" said Koonin. "That might lead to a really interesting set of discussions."

Koonin acknowledged that he may get some scorn for his reports, but if he does, "I think that says something awful about the state of our society and the way in which we can discuss matters."

"What I would like to do is have an honest, open discussion among the scientists that is accessible to the decision-makers and the public and that has not happened," Koonin said. "I think if we can get that in the next few years, we might be able to make wiser choices about which direction we head and how rapidly we head."

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