No, CFCs are Almost Certainly Not Causing All of Global Warming

The right has jumped all over a new paper by Qing-Bin Lu purporting to demonstrate that chlorofluorocarbons, not carbon dioxide, are behind global warming. Since CFC production has tapered off of late, he therefore predicts that we’ll see global cooling for the next 50 years or so. There is a lot of complicated reasoning in the paper (pdf), but I’m confident in labeling it bogus. For one, it’s not the first time he’s made this argument; he published a similar paper in 2009 and nobody bought it back then either. (It’s part of a long tradition of smartass physicists believing they can traipse up to an established field and upend a generation of findings with a the wave of a few equations.)

The math is beyond my time and energy to evaluate closely, but there are a few simple details that don’t smell right. First, Lu doesn’t consider oceanic warming, which is where about 90 percent of the extra heat is ending up. Second, he asserts that the earth has been cooling for ten years or more, which flatly isn’t right.

The thing to remember about these sorts of revolutionary claims is that they are almost certain to be wrong. For every Einstein or Darwin who actually turns science on its head, there are a thousand researchers eager to make their name as The One Who Proved Everyone Wrong, but who fail utterly. Especially for complex topics like climate change, there are all sorts of reasonable-sounding nooks and crannies on which a contrarian scientist can hang a potential science revolution. Combine that with the strong novelty bias of academic journals, and papers that make surprising or interesting claims are more easily published (and a lot more likely to get lots of media attention).

Similarly, it might be that microwave radiation from cell phones causes cancer, but the possible mechanisms are so theoretically dubious that it would require very strong proof which is not so far in evidence. So I’ll keep my eyes peeled for the real expert look at this paper, but for now I’m comfortable sticking with the other 97 percent of published science.

UPDATE: It occurs to me I’ve been a bit imprecise in the wording here. It’s incorrect to say that CFCs are not causing global warming at all; as I’ve explained before, halogenated molecules (which includes CFCs) can be spectacularly powerful global warming agents. Some of them are capable of tens of thousands of times CO2’s warming potential, but don’t have that large of a net effect because of their low concentration. Where Lu went wrong was trying to attribute all warming to CFCs—the actual fraction, according to the IPCC, is about 13-14%.

Ryan Cooper

Ryan Cooper, a contributing editor of the Washington Monthly, is currently the Washington correspondent for The Week.