Interview with Roger Pielke Jr.

Q: Is there evidence to show that the behavior of hurricanes has changed over a long period of time ? Can we explain why those changes have occurred?

A: When you talk about hurricanes, as you know, it’s a subset of the issue of tropical cyclones on the planet, it’s really important to be very careful about what you mean by changes because there are changes in the frequency of storms, intensity, their strength. But also, the thing is that people care about most is of course the impact, the damage and the deaths that occur from storms that make landfall. My view on the topic is : if you look at the statistics of tropical cyclones around the world that start with the landfall, the storms that actually cause impact, we have a study coming out where we looked at all the ocean basins around the world and try to put together a single data set of landfalls. The data is good back to 1970, so it’s barely climate time skills that are thirty years or longer, so we have just over forty years of data. And in that record we see no trends of up or down, we do see some variability but no trends of up or down in landfalls. Some basins like the Atlantic we can go back before 1900, and others like the Indian Ocean, we can only go back to 1970. But there is no evidence and no empirical evidence that the number of storms or their intensity has increased over the last forty years worldwide. And in the Atlantic there is no evidence over the last hundred years.

Q: We saw that after Katrina for example, there was an increasing number of publication, so do you think that now, there would be kind of a consensus between scientists?

A: Yes, I would say that if you take a look at the paper that were published in Nature Climate Change by Tom Knutson in the beginning of 2010 which was really a good consensus statement of the community. And more recently the IPCC Report of Extremes. Chapter 2 deals with the physical science aspects of hurricanes, very consistent with that WMO report it’s been updated. The Chapter 3 deals with the economics which I discussed in my blog. But I would say that on the subject of the nature of the relationship, can signal be detected so far there is a fairly robust consensus within the scientific community. You get a different perspective when you look at the media, or advocacy groups in the political debate, but I think the science is fairly consistent. There wasn’t a brief period right after Katrina when Kerry Emanuel paper came out and the Peter Webster and all came out, but, there was some debate that eructed in the media, in the blogosphere. But that has mostly settled down, if not disappeared. There is very few scientists today who would make claims that we can see signal. There has been a debate over whether that’s because we have better observations we can see more storms versus whether there is actually something going on physically with the climate system. My sense is that it’s largely settled in the direction of observational changes. There was a paper that came out recently by Morris Bender and colleagues, looking at model projection or how tropical cyclones would change with the change in climate (in the Atlantic). And they said that if the models that are used by the IPCC are accurate, then we should expect to see those changes, or to detect them statistically in about 60 years. And that provide additional evidence to explain why it could be the case that we are affecting the climate, it’s having effect on tropical cyclones, we can’t see those effects yet, we may not be able to see them for several generations. The reality of climate change and effects on tropical cyclones could certainly be the case, it’s just maybe we can’t detect those changes at this time. And that’s a subtle message, it’s not a yes or no, black or white issue. It’s more when do you expect to be able to see the signal that you expect to be there.

Q: We found « unexpected » actors in the controversy, they are the insurance and reinsurance companies. What is their role in the research and do you think we can consider then as real actors in the research?

A: I have collaborated for a long time with people at Munich Re insurance which has been one of the most outspoken companies on the topic, and if you take a look at the research they supported, so they supported a big project at LSE in London and the peer-reviewed research that has been published mainly by Eric Neumayer is very consistent with all the work that I have published. But in fact they start out to try to critique or replicate my work, and it turned out that they support it. I would say that the message from Munich Re has over the last 10 years become increasingly in line with what the science says. They have a serious commitment to scientific research, at the same time, they have a serious vested interest in certain outcome related to their research. For better or for worse, those outcomes haven’t come from the research.

Q: What are the current policies about hurricanes? Is there any link between the research on hurricanes and politics?

A: Yes, I would say that the most immediate and significant research has to do with engineering and building. How you build structures land use, and there is a lot of different policies in the US, each of the coastal state has its own approach on buildings coasts and land use. Different countries have different approaches, I think it’s because extreme events capture people’s attention, they are very photogenic, they show up in the news. It’s a very appealing argument to make if you’re a campaigner for action in climate change: ‘look at this disaster, we cause this because of our green gas emissions, we need to change our ways’. The problem is that no one in the scientific community actually believe that if we all of the sudden stop our green gas emissions that would have a noticeable effect on hurricanes. The reason is that we don’t expect to see the signal for a long time to begin with, and if we were to change our energy habits we wouldn’t see the marginal signal for even longer.

Q: Is there anything else that you think is essential to the debate that I might have missed here?

A: My caution would be not to ‘overscientize’ the debate. The debate takes place in the language of science and discusses science, but I would say that most of the time it’s not really about science. It’s about other issues that we bring to science, such as what is the effect on the planet, why should we be taking action, whose voices should be heard or not in the debate. A lot has to do with authority and legitimacy, and political power. My sense is that what you’ll find as you get into this area is the actual quote on scientific debate, there isn’t very much of a scientific debate. What you’ll find is that there is a lot of mapping of the science onto a public and politic debate, and the two don’t match up very well. I put up on my blog a picture of a bunch of people sleeping, to say how interesting is the scientific debate and it’s not very interesting at this point but once you get into the politics, the blogosphere, it becomes a lot more interesting and there is a lot more going I guess than just debate over science.