Saturday, March 20, 2010

The Big Battle Over Climate Science

Discover Magazine interviews a couple of climate scientists: It's Gettin' Hot in Here: The Big Battle Over Climate Science. Judith Curry has some interesting points:

The hockey stick—Michael Mann’s widely cited graph of average temperatures in North America over the past 1,000 years—was attacked by two prominent critics, Steven McIntyre, a former mineral company executive, and Ross McKitrick, an economics professor at the University of Guelph in Canada. Where does that dispute stand?
One would have hoped it would have an outcome similar to the hurricane story, but the hockey stick thing was exacerbated by Michael Mann’s behavior, trying to keep the data and all the information away from McIntyre, McKitrick, and other people who are skeptical of what they were doing. So we’ve just seen this blow up and blow up and blow up, and it culminated in the East Anglia hack and the e-mails that discredited those guys quite a bit. This made us reflect on the bigger issues of how scientists should be interacting with the media and how we should be dealing with skeptical arguments. I think the way that Mann and Phil Jones [the former director of the Climatic Research Unit at East Anglia, who resigned over the scandal] and those guys were going about it was wrong, not just in terms of ethics. It also backfired....
Where do you come down on the whole subject of uncertainty in the climate science?
I’m very concerned about the way uncertainty is being treated. The IPCC [the United Nations’ Intergovernmental Panel on Climate Change] took a shortcut on the actual scientific uncertainty analysis on a lot of the issues, particularly the temperature records.
Don’t individual studies do uncertainty analysis?
Not as much as they should. It’s a weakness. When you have two data sets that disagree, often nobody digs in to figure out all the different sources of uncertainty in the different analysis. Once you do that, you can identify mistakes or determine how significant a certain data set is.
Is this a case of politics getting in the way of science?
No. It’s sloppiness. It’s just how our field has evolved. One of the things that McIntyre and McKitrick pointed out was that a lot of the statistical methods used in our field are sloppy. We have trends for which we don’t even give a confidence interval. The IPCC concluded that most of the warming of the latter 20th century was very likely caused by humans. Well, as far as I know, that conclusion was mostly a negotiation, in terms of calling it “likely” or “very likely.” Exactly what does “most” mean? What percentage of the warming are we actually talking about? More than 50 percent? A number greater than 50 percent?....
Do you subscribe to the argument that today’s climate models are crude and need to be taken with a grain of salt?
No, I think the climate models are becoming quite sophisticated. We learn a lot from the simulations. But you have to keep in mind that these are scenario simulations. They’re not really forecasts. They don’t know what the volcano eruptions are going to be. They don’t know what the exact solar cycles are going to be. There will be a whole host of forcing uncertainties in the 21st century that we don’t know.
You’ve said that climatologists should listen more to bloggers. That’s surprising to hear, coming from a scientist.
There are a lot of people with Ph.D.s in physics or chemistry who become interested in the climate change story, read the literature, and follow the blogs—and they’re unconvinced by our arguments. There are statisticians, like McIntyre, who have gotten interested in the climate change issue. McIntyre does not have a Ph.D. He does not have a university appointment. But he’s made an important contribution, starting with criticism of the hockey stick. There’s a Russian biophysicist I communicate with who is not a climate researcher, but she has good ideas. She should be encouraged to pursue them. If the argument is good, wherever it comes from, we should look at it.

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