“We found that there is just no way that the observed changes [in hurricane strength] [in sea-surface temperatures] could be attributed purely to internally generated natural variability.”

(see correction at bottom of post)

So said Tom Wigley — one of many people at NCAR with more expertise and peer-reviewed papers in the area of hurricanes and climate change than Roger Pielke Jr., but far fewer media appearances — when he and 18 other respected researchers published a study in a recent issue of Proceedings of the National Academy of Sciences. The study, he said, “closes the loop” between climate change and hurricane intensity.

The story quotes Pielke Jr., a prodigious blogger with a PhD in political science, disputing the conclusions of these 19 climate scientists. The credentials behind his self-appointed role as arbiter and schoolmarm on this issue have never been made clear.

Al Gore has publicized the conclusions of Wigley, Emanuel, and other working scientists who believe there’s a strong connection between climate change and hurricane intensity. Is Gore, as Pielke Jr. put it in this tsk-tsk-fest, guilty of “departures from scientific standards”? Are Wigley and his colleagues?

The point is, Gore’s statements are not “scientifically unsupportable.” There is science that supports them. Remember, the IPCC is not original science, it is a review of science, with extremely conservative standards. It did not find a preponderance of evidence in favor of the climate change/hurricane connection sufficient to warrant its inclusion in a consensus document.

I have great respect for the IPCC’s standards. It’s a much-needed baseline-establishing process. I don’t want to let Gore “supplement” or change the IPCC.

What I’m arguing is, there’s no reason the IPCC’s conservative weight-of-evidence standards should be everyone’s, at all times, governing our entire public dialogue or policy-making process. Should no one (including Wigley?) be allowed to have a position on the hurricane/climate change question until the IPCC or WMO says it’s OK?

I’m completely with Andrew that by and large, the IPCC should be the scientific standard in matters climate-related. But on the hurricane question it simply provides no guidance. It doesn’t say there is or their isn’t a connection. We’ll have to make up our own minds based on our own science reviews, or the opinions of people we trust, or various other workaday heuristics. Neither deciding for nor deciding against should brand us “extremists.”

Gore, based on the totality of his knowledge and experience, believes that the work of Wigley et al. will be born out, and is sufficiently strong that it’s worth accepting the connection for the purposes of public education and policy-making. Others disagree. Others resolutely have no opinion until the IPCC makes up its collective mind. So be it.

A couple of other semi-related notes:

  • None of this is to say that I agree with the emphasis many climate advocates place on hurricanes. I don’t. I tend to agree with the statement from a group of scientists on the both sides of the issue that hurricane damage is best reduced by changing perverse financial incentives and land-use patterns, along with nurturing coastal buffer ecosystems. Hurricanes are not the big global warming story, and nothing particular hinges on them, policy-wise. But drawing conclusions about the science before the IPCC doesn’t ipso facto make one a wacko.
  • Andrew, if Inhofe accepted the IPCC generally but argued that there’s no climate change/hurricane link, I’d have no problem with it. He’d be able to find some support in the peer-reviewed scientific literature — a first for him. But that’s not even close to what he’s doing, is it? Which is just to say that what Inhofe and his crowd are up to has nothing in common with what Gore does. They are not parallel “sides” of any debate.
  • Pielke Jr. delights in airily dismissing others as “political advocates,” and pointedly includes the IPCC scientists among those who have “values and political agendas,” but he’s less forthcoming about his own advocacy and agenda. His, um, “outreach” is relentless, and it’s easy to come away with the impression that he’s a climate scientist (in fact Science called him one), though he’s not. In virtually every case, he pops up to criticize those fighting for action on climate change. He is beloved of denialists, wrote for the Cato Institute’s journal to defend Bjorn Lomborg (PDF), and is quite fond of citing a paper he published in a non-peer-reviewed journal that turned out to be a veritable clearinghouse for skeptics. Who else was quoted bashing Wigley’s work? William Gray and Steven Milloy. He claims not to love the climate cranks as much as they love him, but it’s difficult not to raise an eyebrow.
  • As it happens, I don’t care much about any of that. I don’t see anything wrong with being an advocate. I don’t accept that it inherently includes dishonesty. Everyone’s an advocate. Everyone’s views are worth discussing. I hope we can all have a little fun while doing it and not take ourselves too seriously.
  • One thing I do agree with Roger about is that debates over science far too often serve as proxy policy debates. I didn’t want to get bogged down in the science, much less the hurricane science, and plan to move on to more interesting questions post haste.

* John Fleck is right in the first comment. Wigley is referring to sea-surface temperatures. Scientists had found that Cat. 4 and 5 hurricanes had increased. They’d found that sea-surface temperatures had increased in hurricane breeding grounds. They’d judged the two connected. What was left to discover is whether the sea-surface temperature increases were due to natural variation or anthropogenic warming. Wigley et al. determined that it was the latter — that’s the “loop” the study closed.

Again: we know there are more intense storms, we know storms gain intensity from warm water on the surface, we know the surface water is getting warmer, and we have very good reason to believe that the greenhouse effect is warming the surface waters. Everything we know about how the greenhouse effect and hurricanes work leads to the intuitive conclusion that the former is intensifying the latter — intuitions now backed by a growing body of evidence. The WMO doesn’t think the balance of evidence is sufficient to draw a firm conclusion. Wigley does. Gore does. They use this as another — one of many — argument in support of trying to slow global warming. Whether or not you think it’s legit for them to reach this conclusion, you have to have a pretty warped view of the political and cultural landscape to think that it’s equivalent to what Inhofe et al. are doing.