Over the course of this week, you've probably heard at least a little about the controversy surrounding a mistake in the IPCC's 4th Assessment Report from 2007. Short version: The Working Group II section, which covers observed and projected impacts of climate change, states that Himalayan glaciers are "very likely" to disappear by 2035. Glaciologists say that's bogus. And the IPCC report, itself, sources the claim to a position paper put out by the World Wildlife Fund, rather than any peer-reviewed research. The error was first pointed out by scientists within the climate research community. As of yesterday, the IPCC has apologized, and is reviewing how such a sketchily sourced factoid made it into the final report.

So what should you take away from this incident? Two things:

It's a mistake. But mistakes happen, and this really isn't even a big one.



Climate science is science, not a religion. It makes no claim to infallibility. In fact, the whole thing with science, in general, is that it assumes mistakes will happen. Systems like peer review exist to catch those mistakes. Standards, like reproducibility and independent verification, push our knowledge, over time, closer to the truth. The basic facts about climate science—that climate change is happening and that human activities are the most likely cause—don't stand and fall on single sources. They're based on hundreds of peer-reviewed papers that, combined, lead to a robust conclusion. That's different from this claim, which was based on one source, and a flimsy one at that. It shouldn't have made it into the IPCC report. There are some critics who say there are other, similar, mistakes going on in Working Group II. But neither of those things undermines the real science.



It's also worth pointing out that the Himalayan glaciers really are retreating, just not so very fast.

The real problem lies in how the IPCC responded to criticism



While the mistake doesn't undermine the well-sourced facts about climate change, the way it was handled does undermine public confidence in those well-sourced facts. And that's a big problem. A scientist who reviewed the Working Group II report says he spotted the mistake before publication, and was ignored. A scientist who pointed out the mistake after publication, in a report prepared for the Indian government, was publicly criticized as a practitioner of "voodoo science" by IPCC chairman Rajendra K. Pachauri.



It's not OK that it took resounding pressure by the scientific community and the press in order to get this addressed.



Climate scientists have to deal with a whole lot of crap. Most of the time, that crap is about as well-sourced as this glacier claim. So it is, on one level, understandable that some scientists have developed a knee-jerk "circle the wagons" response to criticism. But that response is very, very bad when it starts being applied to any criticism. The Internet can't make us all armchair experts, so we have to rely on the people who really are experts to tell us what's going on—and we have to be able to trust them to self correct. The experts did that here, but they did it in a way that—to the average layman—made it look like they're more interested in being "right" than being accurate. That can't happen when there's so much at stake.

Where'd this all come from? Check out my IPCC Glacier Controversy reading list:

Image courtesy Flickr user ricardo.martins, via CC