By Chris Mooney

Last month, a scientific paper appeared that kicked off what is, by any stretch, the most interesting climate science debate of the year.

In the paper, former NASA climate expert James Hansen, who is widely credited with putting the climate issue itself on the map, collaborated with 16 other researchers to outline a pretty dire climate scenario. Their vast paper contemplated alarming new climate feedback loops involving the Southern Ocean, which could lead to rapid Antarctic ice sheet destabilization and dramatic sea level rise, potentially in this century.

In 2013, the consensus body of climate science, the U.N.’s Intergovernmental Panel on Climate Change, stated that sea level rise by 2100 could, at the high end, be about a meter. But here in this paper were Hansen and colleagues suggesting it could be “several meters” within 50, 100, or 200 years, depending on how fast the rate of ice loss from Greenland and Antarctica is able double.

The Hansen study, however, had not yet been peer reviewed. It appeared in a “discussion journal,” Atmospheric Chemistry and Physics Discussions, where peer review happens in the form of public, published comments. After that, reviewers and the journal decide on whether to formally publish the work (in Atmospheric Chemistry and Physics), and with what revisions…

…So let’s go through a few comments to show you what’s going on:

A stellar review by the first assigned peer reviewer. The single most important comment to read on the paper is the first of two to three officially solicited peer reviews. This one is by geoscientist David Archer at the University of Chicago. It effusively praises the new paper, calling it “another Hansen masterwork of scholarly synthesis, modeling virtuosity, and insight, with profound implications,” “breathtakingly rich and panoramic,” and referring to Hansen as “a creative and intellectual volcano.”

Granted, Archer suggests that some parts of the paper may not belong—remarking that the work is very long and some sections are more tangential than others—but emphasizes its “important conclusions, primarily about the ice sheet melting climate feedback.” Above all, Archer makes a very important statement. He says recent discoveries about the vulnerability of West Antarctica, which are at the center of the Hansen paper, “make the IPCC prediction for year-2100 sea level rise clearly obsolete…”

Continue reading at the Washington Post…

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