Hurricanes and Global Warming: Interview with Dr. James J. O'Brien

Dr. James J. O'Brien is Director of the Center for Ocean-Atmospheric Prediction Studies at Florida State University, where he is the Robert O. Lawton Distinguished Professor of Meteorology and Oceanography.

James Glassman: Dr. O'Brien, in the wake of Hurricane Katrina – in fact, within hours after Katrina hit – we heard a good deal of criticism, mostly from supporters of the Kyoto Protocol that the President and others had not done enough to stop global warming and that this hurricane was, in some way, caused by global warming. You are an expert on hurricanes: do you think that global warming has had an affect on the intensity of hurricanes?

Dr. James O'Brien: Absolutely not. All of the people who are hurricane scientists or teach about hurricanes at the graduate level that I've talked to agree with me.

Glassman: So the notion that the global warming advocates have – which is that there's more carbon dioxide pumped into the atmosphere which warms the surface of the earth, this is a phenomenon that's basically been increasing during the century.

O'Brien: Right.

Glassman: You would expect to have a fairly regular increase in hurricanes.

O'Brien: Well, let me give them some due, OK? Their contention is that the ocean is warming up and if the ocean warms up, we should expect stronger storms, OK? That's a reasonable theory.

Glassman: Right.

O'Brien: The problem is, what I've also looked into, is that if you actually – and they sort of believe that the sea water in the globe has warmed up about a half degree centigrade in the last 50 years or so.

O'Brien: But what's amazing is if you actually looked at the trends in the Atlantic Ocean – the region where hurricanes form from five north to 20 north – from Africa over to the United States, it's actually cooling down. So, I mean yes, there are hotspots in the globe which are warming up, but not in the Atlantic hurricane formation region. So, their theory doesn't really hold water.

Glassman: In fact, is there a cycle of hurricanes?

O'Brien: Yes. There actually is. You know, for the Atlantic region, some scientists have very carefully gone back in time to 1851 and recorded all the hurricanes that hit the United States. Everybody should realize before about 1970, we didn't have adequate satellites. So hurricanes occurred in the Atlantic that nobody knew about and certainly, didn't have measurements on them. But every one that hit the United States, there's certainly newspaper or diaries or other information and so, all of these things have been recorded.

If you take the strength of the hurricanes at landfall from 1851 to 2004 and plot it up, you'll see this remarkable semi-periodic thing come out with about 15 years or so of many storms, strong storms and then 15 years or so with much reduced storms and then 15 years… and it just keeps going like that over the 150 years we have records of. And so if you look at this long record, you'll see that there's absolutely no evidence of any increase in strength. Of course, in the periods when we have a lot of storms, you're likely to have stronger storms; and in the periods where you have less storms, you're likely not to have strong storms.

Glassman: Let me just pursue this as far as Katrina is concerned because we certainly heard lots of reports that the reason that Katrina intensified so much when it got into the Gulf of Mexico was that the Gulf itself was very warm, but is that a consequence of global warming?

O'Brien: No, it's really funny.

Glassman: You're laughing.

O'Brien: Yes, I laugh because the entire Gulf of Mexico in the summertime in August is over 90 degrees, OK. In other words, if I take the records from the last 50 years and average it out to get what people think is the normal temperature.

Glassman: Right.

O'Brien: It's always 90 degrees in the summertime, everywhere. So, it was 90 degrees and its always 90 degrees.

Glassman: So, the real problem here was that Katrina was really timing. I mean Katrina was a storm that, unfortunately, spent time in the Gulf of Mexico during the time when the water was hot.

O'Brien: Yes. I don't know the steering, but however it got disturbed going over the peninsula of Florida. What surprised everybody was when it came out into the Gulf of Mexico, it did this jog to the south. If you remember, it was going southwest for a while and that allowed it to get so far away from land that it had a long way to go before it was going to come back on shore.

Glassman: Sort of a running start.

O'Brien: So yes, it had a – you know, it's a long distance. It was going about 10 to 15 miles an hour. So it had a long time to gather up, from long distances, all this moisture from this hot water.

Glassman: Now, are you saying that people who study hurricanes do not feel that the reason that Katrina, or any other recent hurricanes, have been so intense is that the surface temperature of the earth has been increasing?

O'Brien: With regard to people who work on hurricanes or are knowledgeable about the tropics – I don't know of anybody who would think that global warming is causing Katrina.

Glassman: Thank you very much Dr. O'Brien.

O'Brien: OK. Right, thank you.

First appeared in Tech Central Station.

James K. Glassman is the host of TechCentralStation.com.