Trouble notoriously comes in threes, and so it goes for the climate science community and the organizations that have sought to advance action to slow global warming. First came the disclosure of the East Anglia e-mails, casting doubt on the 1000-year temperature record. Then there was the embarrassing treatment of non-governmental organizations at the ill-organized Copenhagen climate conference. Now there's the discovery of an egregious misstatement about the fate of Himalayan glaciers--not a minor matter--in the IPCCs most recent report, specifically the second volume on impacts.
The error is described in a letter to the editor by J. Graham Cogley of the University of Toronto, which Science magazine posted this week. The panel's Working Group II, in a technical report that was supposed to be based on authoritative, peer-reviewed scientific findings, said that the Himalayan glaciers probably will disappear by 2035 and that their area might shrink from 500,000 square kilometers to 100,000. According to Cogley, the first statement turns out to be based on a news story that had appeared in New Scientist, "about an unpublished study that neither compares Himalayan glaciers with other rates of recession nor estimates a date for disappearance of Himalayan glaciers"; the indefensible statement has been widely quoted, including by the Intergovernmental Panel's chairman. The second statement (which by the way seems obviously inconsistent with the first) appears to have been taken from a published statement that referred to shrinkage in the year 2350, not 2035.
The Intergovernmental Panel on Climate Change, winner with Al Gore of the Nobel Peace Prize, regularly issues multi-volume reports that are meant to represent the carefully honed consensus of hundreds of accredited climate scientists from all over the world. Caught in errors that make its vaunted process look bush league at best, the IPCC has issued a categorical apology, which Roger Pielke Jr has posted on his website. Pielke has blogged about this latest embarrassment, which also has been thoroughly covered in the New York Times and in Andrew Revkin's climate blog.
To get a reaction to the IPCC embarrassment and the larger Himalayan ice issue, I contacted Lonnie Thompson, professor and research scientist in the Byrd Polar Research Center at Ohio State University. Thompson pioneered the study of tropical and subtropical mountain glaciers, starting in Peru in the early 1970s, and he has studied glaciers in every part of the world. Fortuitously, I found Thompson sitting in his office with Yao Tandong, director of the Tibetan Plateau Research Institute, which is based in Beijing and has an outpost in Lhasa.
Thompson points out that the IPCC reports are intrinsically conservative "because every country in the world including Saudi Arabia has to sign off on them." Without belittling the glacier error, he points out that it occurred only in the technical report, not in the executive summary. (But that's an argument that cuts both ways: yes, the authors of the executive summary get credit for not having repeated dubious and unsupported statements; but it's the technical report, after all, that is supposed to be technically bullet-proof.)
What about what's substantively at stake? Billions of Asians depend on rivers fed by the Himalayan glaciers. Thompson says flatly that no credible scientist claims to know what will happen to them, or even how much ice is in them. However, with Yao's assent, he insists on this bottom line: From 1980 to 1995, 90 percent of the Himalayan glaciers retreated, and from 1995 to 2005, 95 percent. And those same patterns are "right in line" with what's also been found in the Alps, Alaska, and South America.
Thompson expresses confidence that the IPCC, in its next round, will make extra sure that all peer-reviewed assertions really are peer-reviewed. He does see an argument for IPCC procedural reform, in that it's a process in which "everybody wants to play an equal part though not everybody is scientifically equal." At the same time, he's alarmed at the constant harassment climate scientists are getting from critics, and fears for the future of the field.