Stormy weather

Are hurricanes getting stronger? Has Al Gore vanquished the climate change skeptics? "Storm World" author Chris Mooney discusses the heated scientific debates about global warming.

By Katharine Mieszkowski

Read more: Books, Science, Interviews, Authors, Global Warming, Katharine Mieszkowski, Books Interviews

July 16, 2007 | Science writer Chris Mooney grew up in New Orleans. Just 100 days before Hurricane Katrina made landfall in Louisiana, he sounded the alarm in the pages of the American Prospect about the Big Easy's extreme vulnerability to a major storm. Katrina even swamped his own mother's home in the Lakeview neighborhood. But you won't find Mooney, author of "Storm World: Hurricanes, Politics and the Battle Over Global Warming," joining the chorus blaming the devastation and deaths in New Orleans on climate change.

As Mooney reports in "Storm World," many scientists believe a warmer world is likely to make hurricanes on average more intense, and some even argue that we're already seeing those effects. Yet, the leap from those premises to "Global warming drowned New Orleans!" is the sort of slipshod, unscientific reasoning that makes Mooney bristle.

In "Storm World," Mooney delves into the heated scientific debate about hurricanes and climate change, where there are still many unanswered questions, such as: Will a warmer world mean more or fewer storms? It makes for a revealing look into how scientific understanding haltingly lurches forward, saddled by imperfect data about the past, even as it tries to use that data to divine the future. Since Hurricane Katrina, the question of what global warming will mean for hurricanes has become as high-stakes and high-profile as any in science, made all the more prominent by political scandal. As Mooney, also the author of "The Republican War on Science," tells it here, again and again the Bush administration's clumsy attempts to suppress its own scientists' findings transformed what could be just the release of yet another scientific paper into front-page, breaking news.

Yet in this book, Mooney is less concerned with the political distortion of scientific findings, and more fascinated by the findings themselves, and the methodologies behind them. Sure, he gives us tales of meteorologists flying into the eye of fearsome storms to gather data firsthand. But the real drama is found behind the lectern at prestigious scientific conferences, where hurricane experts and climate modelers put forth and pick apart competing theories about monster storms that can bring about an 18-foot storm surge and 150 mph winds.

For better or worse, ferocious hurricanes have become the most potent symbol of what we have to look forward to in a world changed by global warming. Just think of the movie poster for Al Gore's "An Inconvenient Truth." In this hothouse atmosphere, "Storm World" tells a story that is neither a polemic, nor an excuse to throw up our hands and do nothing to protect ourselves from the worst-case scenarios.

Salon spoke by phone to Mooney, now the Washington correspondent for Seed magazine who also blogs at the Intersection, about what the 2007 hurricane season portends, the fate of New Orleans and crocodiles in Greenland.

Why do some scientists think that hurricanes may get more intense as the world warms?

The prevailing hurricane theory is that they're heat engines. Their energy source is the warm tropical sea surface. If you increase that heat content, you can get more power out of the heat engine.

The first time that anyone said hurricanes should intensify because of global warming was about 20 years ago. Some scientists now think that they have data to show that hurricanes have intensified. The data shows a dramatic increase, which is not accepted by everybody.

Won't the sea-level rise caused by climate change mean greater hurricane death tolls and damages?

Without a doubt.

Sea-level rise is a slow, but very certain aspect of global warming. Every hurricane will be going over a higher ocean in the future. When a hurricane hits a place, the storm surge should be able to penetrate further inland. There's just no doubt about that.

One provocative hypothesis argues that hurricanes have always naturally played a role in regulating climate, so global warming will change that, too. Can you explain that theory?

Kerry Emanuel at MIT is the leading proponent of this idea that there is a two-way relationship between hurricanes and climate.

A warmer climate should intensify hurricanes on average. If hurricanes do intensify, there will also be more heat driven toward the poles, because hurricanes are drivers of heat through the ocean.

So, what is the implication of warming the poles?

You end up with a world someday that looks like the Eocene epoch, which is Emanuel's analogy. During the Eocene, the world had incredibly high sea levels, crocodiles in Greenland -- things like that.

You would have a world in which the gradient was less between the equator and the poles. The poles would still not be as warm as the equator, but they would be proportionally warmer in relation to it.

How have global warming skeptics played a role in the debate about hurricanes and climate change?

One of the top global warming skeptics happens to be a hurricane specialist. That's Bill Gray at Colorado State University. He has played an incredibly huge role just by virtue of the fact that he's Mr. Hurricane, and he doesn't buy this stuff.

But he's not one of those climate skeptics who has been bought and paid for by industry?

No. He's from a generation of scientists who did a different form of research than the computer modelers today who are driving a lot of the climate concern, and he doesn't accept their methods. He's a data guy, and he doesn't think that the modelers can do what they claim, which is project future climates. He doesn't think that there's enough reliability there. The modelers would, of course, disagree, and they've more or less won that argument in terms of what the scientific community thinks.

Between Al Gore's "An Inconvenient Truth," Hurricane Katrina, and the change in the House and Senate, has the influence of the global warming skeptics waned? Are they just less important than they once were?

A lot of things have beaten them back, including the passage of time. The issue has turned on them. They're the losers now. They put on a great holding action for a really long time. And, they delayed us from solving the problem.

Now, it's turned against them. News articles are much less likely to be "balanced" between the skeptics and the scientific consensus than they once were. The media tells a lot of different narratives about how Christians are coming around to wanting to save the environment because of the stewardship imperative that they feel, or industry is coming around. All of these things helped bury the skeptics. The skeptics seem sort of irrelevant the more everyone turns toward doing something.

How did media coverage of Katrina exaggerate the science around hurricanes and global warming?

It was a time of national tragedy and crisis, and a lot of people were shocked at these incredible images they were seeing. In that context, there were some very incautious statements about the idea that Katrina might have been caused by global warming.

You can't say that scientifically. It gives a misimpression about how all of this works, because of a simple error of statistical reasoning. Global warming might explain a trend, but it can't explain an individual event, like Katrina.

Global warming might make it more likely to have an intense hurricane any time you have a hurricane. But in terms of, Why did the disturbance that became Katrina form? Why did it end up in the Gulf rather than going up the East Coast? How did the winds blow Katrina in one direction rather than another? All of these things global warming doesn't have anything to do with.

It's weather.

Considering that the scientific debate is still going on about hurricanes and global warming, why do you think that hurricanes have become such a symbol of what we have to fear in a warmer world?

Greenhouse gases are invisible. Literally. You can't see them. And hurricanes, by contrast, are the most terrifying, sublime things on the planet. So, you go from the extreme of non-telegenic to the extreme of incredibly scary and incredibly visual.

Next page: "We will have bad hurricanes again, and I don't think that we're prepared for them"