By Gayathri Vaidyanathan

The world’s largest organization of physicists clarified its position on climate change last week, and it no longer believes, as it did in 2007, that the evidence for global warming is “incontrovertible.”

Instead, the American Physical Society (APS) now states that climate change is a “critical issue that poses the risk of significant disruption around the globe.” It then discusses uncertainties inherent in climate science and the risk involved in not taking action in a draft statement that was released last week (see below for the 2007 and draft 2015 statements).

To some, the latest version improves on a word — “incontrovertible” — that seems to conflict with the basic nature of science, but to others the change could sow confusion in the minds of the general public…

…The process of putting the statement together was “painful,” said Robert Rosner, an astrophysicist at the University of Chicago and an APS member involved in the drafting process until December 2014.

That a group of seemingly staid physicists could come to metaphorical blows over a previously accepted climate statement reflects just how politically charged the issue remains.

Controversy over ‘incontrovertible’

The roots of the conflict can be traced to 2007, when the APS released a statement on climate change stating, “The evidence is incontrovertible: Global warming is occurring.”

According to the Merriam-Webster dictionary, “incontrovertible” means “not able to be denied or questioned.”

This term was anathema to scientists. In science, everyone is free to question everything, and that is how the field progresses.

“A few physicists got their knickers in a twist over that one,” said Philip Taylor, a professor of physics at Case Western Reserve University and an APS member.

Revision of the statement fell to a six-member drafting committee headed by Koonin, director of New York University’s Center for Urban Science and Progress who has previously served as an undersecretary at the Department of Energy and as a chief scientist at BP. Koonin did not respond to ClimateWire’s request for comment by deadline.

In January 2014, Koonin organized a symposium in Brooklyn, N.Y., to which he invited six climate experts. Three are well-respected by most scientists.

The other three — John Christy, a climate scientist at the University of Alabama; Judith Curry, a climatologist at Georgia Tech; and Richard Lindzen, an emeritus physicist at the Massachusetts Institute of Technology — are well-respected by climate skeptics and are often challenged by the climate science establishment.

These scientists were invited because the APS committee wanted to rebut a claim that skeptics often make — that mainstream scientists are willfully silencing dissenting voices, Rosner said.

The skeptical scientists got a fair airing at the APS’s symposium, where the attendees could separate the wheat from the chaff, Rosner said. The attendees were trained physicists, and at the end, they understood that the skeptical scientists’ “critique of science itself was extremely weak,” he said.

Rosner’s takeaway from the meeting was that Curry, Christy and Lindzen were questioning the presentation of the science, he said.

New wording from the ‘POPA’

In February 2014, Koonin’s drafting committee briefed the APS’s Panel on Public Affairs, colloquially known as POPA, on its activities.

Some POPA members became concerned. They felt the climate statement was too important to be written by physicists who had little or no training in climate science before receiving a one-day crash course from a mixed bag of instructors.

“There was a contingent of folks who were supremely concerned that we would give ammunition to the other side, meaning the deniers,” Rosner said.

In the spring of 2014, Koonin’s drafting committee produced a statement that attributed equal weight to human influences and natural variability as a driver of climate change, according to a source who declined to be named.

That would be disputed by many climate scientists. The Intergovernmental Panel on Climate Change says that it is extremely likely that human activity has been the dominant cause of global warming since the 1950s.

Koonin quickly lost control of the committee, according to a June POPA meeting’s minutes. Elbows came out, and POPA members presented a series of amendments and strong-armed their way into the drafting of the review, according to the minutes.

“Physicists can be emotional,” Rosner said, laughing. “Some of us are really passionate.”

Koonin resigned shortly thereafter. The larger POPA panel prepared the draft, in its present form, by the fall.

Shock Waves from Wall Street Journal

The public face of the spat played out in The Wall Street Journal. In September 2014, Koonin wrote an editorial where he acknowledged human-caused climate change was happening but wrote that the “impact today of human activity appears to be comparable to the intrinsic, natural variability of the climate system itself.”

His article contained some inaccuracies, Raymond Pierrehumbert, a geophysicist at the University of Chicago, said on a phone call from Sweden, where he is on a guest professorship. He said that human influences are not just “comparable” to natural variability as Koonin wrote. Rather, humans have dominated warming since the 1950s.

This may seem like a minor squabble, but Koonin’s point is one espoused by Curry and other scientists opposed to man-made dominance of global warming. They assert that the climate is indeed changing, but nature and humans both share the blame. The degree to which humans are dominating nature in shaping the climate, they assert, cannot be known using the tools scientists presently have at their command.

Continue reading at E&E Publishing…

Read More

Areas of Focus: Climate Change
Climate Change
Climate change is an urgent global challenge. EPIC research is helping to assess its impacts, quantify its costs, and identify an efficient set of policies to reduce emissions and adapt...
Climate Science
Climate Science
EPIC’s interdisciplinary team of researchers is contributing to a cross-cutting body of knowledge on the scientific causes of climate change and its social consequences.