TNR interviewed climate scientist Stephen Schneider, who I saw speak last week. Schneider wrote a paper in the 1970s about possible global cooling, which contained data that was later determined to be faulty. But the paper continues to be fodder for global warming deniers:
Q: Given your early mistake about global cooling, why should we believe that scientists are better now at figuring out climate change?
A: There’s always the possibility of error. There’s always the possibility you left something out. But what we now have is an accumulated preponderance of evidence and that’s why the confidence is so much higher now than it was then.
Q: And also continued uncertainty.
A: There is always uncertainty as well, but as scientists we’re always trying to move the needle toward more confidence. More confidence does not mean 100 percent confidence. The only thing the IPCC ever said it was 100 percent confident in was that it has been warming over the last 150 years. Some try to frame climate change by saying that as long as there remain open elements, it isn’t "proved." That’s a fraudulent frame. Nobody in this world--in medicine, investment banking, military security, environment--is ever 100 percent sure of anything in a complex system.
When I’m asked, "What is the probability that the Greenland ice sheet will melt if temperatures rise X degrees?," I speak in percentages. My very good friend and colleague Jim Hansen says, "One degree." I don’t think Jim knows that. I don’t think I know that. The problem is too complicated for us to know that, so I frame it as a risk management problem: One degree? 25 percent chance. Two degrees? 60 percent chance. Three degrees? 90 percent chance. Is that the truth? Of course not. That’s as honest as I can be based on my subjective reading of the evidence. However, just so you don’t think I’m an optimist relative to Jim, I also think there’s a 5 percent chance that it’s already too late.
Read the whole interview.
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