'So Far There Is No Particular Evidence That Says Harvey or Katrina or Sandy Were Exacerbated by Climate Change'

As Hurricane Irma pummels Florida, and armchair scientists blame global warming, a reminder from Reason Science Correspondent Ronald Bailey that data does not yet support the hypothesis of stronger hurricanes.


After having pulverized islands such as St. Martin and Cuba, Hurricane Irma is now pummeling South Florida. As happens every time a large natural catastrophe hits the United States, the media is filled with assertions that the calamity's magnitude is attributable to climate change:

But as Reason Science Correspondent Ronald Bailey noted in a links-rich piece on Aug. 29 in the wake of Hurricane Harvey, while there is a widely shared hypothesis that a warming climate will cause more intense hurricanes, so far that theory has yet to show up in the available data. Two days later, as Irma was gathering energy in the Atlantic, The Fifth Column podcast had Ron on for 40 minutes to further explore the connection between climate change and hurricanes, and also between federal policy and natural disasters.

You can listen to the whole show at this link, and at the bottom of this post. Below is an abridged transcript of our conversation, with some hyperlinks added. Make sure to also check out Nick Gillespie's Reason Podcast conversation about Harvey-related policy with Ray Lehmann of R Street.

I started by asking Ron to "walk us through the relationship between climate science and hurricanes, because people talk a lot of bollocks."

Bailey: It is the case that the climate computer models are all more or less projecting that as the planet warms there should be at least more intense hurricanes—probably fewer, but more intense over time. The question is, are we seeing that in the data now?

I've talked to a bunch of different scientists, I've read through a whole bunch of different aspects of the peer-reviewed literature, and they say frankly say, "No, we can't find it there yet. We don't see any intensification going on in the Atlantic region at all. We don't see [that] the number of hurricanes is increasing or decreasing over time." Basically they're saying that the models tell us this will eventually happen, but we don't see it [yet].

There's something called the Accumulated Cyclone Energy Index, which, making it short, is basically a way to add up all the power of all the hurricanes that occur in a particular area. And that one's been going down 10 years in the Atlantic area. So it's not there.

It may be there, we'll see if the models are right, but so far there is no particular evidence that says Harvey or Katrina or Sandy were exacerbated by climate change. They may have been, but the data is so noisy that it's impossible to say for sure. And of course what's happened in politicized science is, any time a catastrophe occurs, somebody is going to stand up and say "Well it's consistent with climate change." Well it's consistent also with no climate change….

There are a lot of people working on what you'd call attribution of extreme weather events, trying to figure out how much of a weather event we could attribute to climate change, how much worse it is because of climate change. But very specifically in the case of floods and hurricanes there's really little data on it at this point. We just don't have enough information.

Kmele Foster: We have seen this theme come up a bunch of times….Isn't it true that these are happening more frequently?

Bailey: Not in the current data, at all. In fact there were more hurricanes back in the middle of the 20th century then has occurred lately. There was an uptick at the beginning of the 21st century in the Atlantic again, and then it's gone down. It's very hard to predict these things.

Part of it has to do with things like the Atlantic Ocean has a 40 to 50 year period where the water is warmer or colder. At the moment it's flipped to a warm phase, and some thought it would soon flip to the cool phase, which means there will be even fewer hurricanes if the models are right.

So again, there are a lot of people working on this, and we may get to that point—"we" meaning the people I'll be quoting as scientists some day—will get to the point of being able to say, "Yes, we can definitely find trends in the data." But the trends in the data don't exist yet.

Welch: Just to dumb this down so I can understand it: The theory, which has not yet been data-fied, relies on "Hey look the globe's getting warmer, the water's getting warmer, stuff that used to be ice is melting. Therefore, that means there's going to be more material for hurricanes to use." Is that right?

Bailey: Right. Basically…hurricanes spin up when the temperature of the water is over 79 degrees Fahrenheit. You have to have that as a threshold in order to get a hurricane. There's a lot of other things you'll need, but assuming that's going on then, yes, you'll likely have more hurricanes, though there's other ways around that. The other thing, of course, is a warmer atmosphere holds more moisture, so when you do have a hurricane you're probably going to have more rain. These are all very good theoretical projections, but the data have not yet supported that.

Welch: In terms of policy here, the things I'm seeing the Trump administration getting knocked for is that they have lessened the Obama administration's emphasis on thinking [about] or causing people to consider climate change when they're looking at something from a national defense perspective, perhaps some infrastructure things as well. You wrote a great piece—and we…do this perennially at Reason, talking about the super perverse incentives, federal incentives particularly, having to do with home insurance in flood areas. This is also true for fire areas, like in southern California and Malibu and places like that. As you look at the applied policies that exist here, what sticks out at you as something that could, that should, change, in order to create a world that's less vulnerable to big-ass storms?

Bailey: Well, don't build on a floodplain, don't build on a coastal area where hurricanes come in. The problem is that in 1968 the federal government decided that they were going to create the federal flood insurance program: It's 25 billion dollars in the red now, and there's no way for it to get out of it without taxpayers bailing it out; there's simply no way to do it. Now that Houston has occurred it's probably going to go through its 30 billion dollar debt ceiling that it has.

So it's simply a failed government program. What it does is that it subsidizes people with cheap insurance to build expensive houses and businesses in flood plains and on coastal areas. Why are we doing that? The market wasn't broken in 1968. The insurance market was telling people, don't build there, because we're not going to insure you. If you build there your stuff is going to get washed away and you'll lose your business and your house, and instead the government said "Nah, we're going supply you with some cash, go ahead build there." So what we've ended up doing is encouraging people to live in areas where they put their lives and their property at risk, increasingly, and it's just stupid.

So what we need to do is change the flood insurance program to a system that's rational, where people will actually pay the premiums for the risk that they're bearing instead of imposing it on taxpayers.

Foster: There's a related issue. We have, in fact, seen disasters be more costly—that is not necessarily a consequence of more severe storms, but has a lot to do with the incentives that we're creating for folks with programs like this.

Bailey: Right, but it's not only that, though. As a procedure, if you normalize things, if you try to figure out what storms in the past would've destroyed if the amount of property currently existing at least were there then, what we find is that in fact the damages have not been increasing as a percentage of the GDP. What's happened is that we're putting more property in harm's way.

Welch: And also talk briefly about lives lost as a percentage according to these natural catastrophes

Bailey: They've been going down dramatically over time. Unfortunately because the screwups of all kinds of things, there were 1,800 people who lost their lives at Katrina. But the basic trend in the United States has been for decades for fewer and fewer people to die in floods and hurricanes. Post-Katrina has been about [five] people a year, and unfortunately it's ticking up here in Houston apparently. But again it's going way, way down.

Why? Because people have much better infrastructure, we have much better response systems, people get more warnings, everything is better, because we're wealthier and have more information at our fingertips….This kind of information infrastructure is allowing people to take care of themselves without the government getting in the way much more easily now, and we should let more of that happen. […]

Welch: Of course you're right about this, of course we're right about this in talking about it, it makes rational sense. And there are people who are trapped in their attic as we speak, underwater in Beaumont, Texas and greater Houston, in an area that's larger than the state of Connecticut or some damn thing, where all the water is, and are you seriously going to lecture them about how "You're getting too many subsidies here from the federal government"? It's very, very difficult, people pay attention to these stories precisely when there's a catastrophe, and that's when their appetite for hearing about preserving perverse incentives and government waste is at its all-time lowest.

Bailey: What we should take away from this—and the flood insurance program, by the way, is coming up for reauthorization at the end of September—what should be taken away from this is, fine, it's terrible that you people were encouraged to build in these areas; you probably didn't even know that that was what was going on. But here's what the deal is: You'll get bailed out this time, but you don't get to rebuild on a floodplain. Here's the money, your house is paid for, go somewhere else where you don't get inundated in the future.

I think you're right, there's no way to basically say "tough luck" to our fellow citizens. That would be cruel and unusual, since they got duped into moving to these places in the first place. But certainly don't allow people to rebuild in areas that flood like this. You're endangering them, and you're obviously wasting a lot of money on property that's not going to be sustained.

Welch: To be clear: They can build there, you're fine with that, as long as they pay the risk premium

Bailey: Absolutely, it's fine if you would like to do that; that's not a problem with me. I just don't think that the rest of us should have to pay for that. […]

Foster: There are the Naomi Kleins of the world that are saying this is the moment—this is when we ought to be talking about climate change, right now. I mean, Ron, I'll ask the question straight out, perhaps I should have asked at the front end so people know whether or not they should trust you: Are you a climate change denier?

Bailey: By no means. I believe that humanity is in fact changing the climate by burning fossil fuels and filling up the atmosphere with extra carbon dioxide, and in the long run if we keep doing it it'll become a significant problem for humanity, so we should be doing something about it. That being said, then we have to get into the policy details of what that something should be, and that's of course where the fight comes.

What I love about Naomi Klein is that she puts it right out there in her book, This Changes Everything, [that] the great thing about climate change is that is gives us an excuse to enact a progressive agenda that we've been wanting for decades. And she just flatly says that— "We can finally put capitalism in the grave." Well that's one policy response, I have a different one I think. I think we can utilize markets and human ingenuity to solve the problem over the course of this century.