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

Published July 16, 2007 11:54AM (EDT)

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.

Do you think that Hurricane Katrina, for better or worse, is one of the reasons that the global warming issue broke through?

Oh, without doubt. For members of the public, there is this link between Katrina and global warming, maybe not fully articulated, but it's in their minds.

There was so much fear about hurricanes right after Katrina. But then the 2006 hurricane season, which was predicted to be pretty bad from the point of view of the U.S., was a bit of a bust. Do you think that kind of lull, even though it's just one year, will make us complacent about hurricanes again?

The forecasts were wrong. This doesn't in any way change the fact that we have a lot to worry about. Maybe this year, again, the forecasts will be wrong. That's kind of the nature of the beast.

We will have bad hurricanes again, and I don't think that we're prepared for them. It's also important to bear in mind that globally there were some amazing hurricanes in 2006, just like now. We just had our first Arabian Sea Category 5.

If you look at the global picture, 2006 still broke records, just like 2005 -- different records. It just wasn't the year for the Atlantic.

There will always be dead years, but Kerry Emanuel said he doesn't think that there will be a dead decade. We'll always have off years, but won't have an off decade.

But the hurricane forecasters think that this year will be a busy one in the Atlantic?

Yeah. It's better than no information at all, but I'm not going to say it's truth, and in fact there's now a contradictory prediction.

Who is making that one?

There's a new form of hurricane forecasting, using climate models, and they actually think this year will be just average.

We're going to know who is right, and who is wrong. It's good for science. One methodology is to run a model, and see how many hurricanes appear, and run it a million times, and then see what the average is. That's what the newest thing is and it takes immense amounts of computer power that few people can do.

Then, the other one is Bill Gray's approach, which doesn't have to use a computer at all. It asks: What's the correlation between the different climate factors that we're starting to see for this year, and hurricanes from previous years that have had those factors, and then we'll just extrapolate. That's called statistical technique, and that's what he pioneered, which is one of the reasons that he's so famous. But it doesn't always work.

In recent decades, there's been a major increase of population in many of the coastal areas in the U.S. that are most vulnerable to hurricanes. One thing that hurricane scientists agree on is that this phenomenon will lead to many more lives being lost and much more property being damaged by future hurricanes. In fact, a number of leaders in the field recently put out a statement denouncing our "lemming-like march to the sea." Is there anything that can be done to slow the increase in coastal development?

All the data shows that the population density of coastal counties is increasing. But the insurance industry is starting to change the models that they use to assess risk, and they're fighting with the states that regulate them. In many cases the states want them to keep insuring.

It would clearly be better not to be having the coastal migration that we have. So, the priorities and the policies aren't aligned because people like to live in beautiful places with water. If there is enough destruction -- and we may have already seen that start to happen -- I think that the market itself will probably do some of the "correcting."

In the meantime, the fact that there are lots of people living near the coasts who are incredibly vulnerable and exposed means there has to be incredibly strong enforcement of building codes, and really well-planned-out evacuation routes and schemes.

We need to continue to invest in hurricane forecasting. The errors have decreased, but not enough, and certainly not in forecasting the storm intensity. All those things will make us safer, so we can actually warn people and get them out. People are there and we have to protect them the best we can.

When it comes to the impacts that global warming will have on hurricanes, much is still unknown. Yet, you argue that we should take action. Why?

The lack of complete knowledge is not a reason for doing nothing. In fact, we never have complete knowledge. Any decision is based upon what we know at the time, and what we have to worry about if we don't do anything.

We have to get away from this idea that science provides certainty, and once you've got the certainty then the action is obvious, because that's just not how it works. You never really have the certainty, and even when you have it, there's a whole range of things you could do, and one of them is do nothing.

But with so much at stake, you have to do something. The best you can do is say, This is the science now. This is troubling. This is worrisome. So, when I think about my planning for the long term, I'm going to have this as part of it. Now it looks like the Army Corps of Engineers is actually doing that in New Orleans, which is good news. Now, we just have to do it for every other vulnerable place in the country.

You're from New Orleans, and your mother's house was destroyed by Katrina. Given the city's vulnerability to hurricanes, and the danger of global warming making them more intense, what do you think of the rebuilding efforts? Do you think it's unwise to rebuild below sea level in that location?

Without protecting it.

My view is, this is a country that put people on the moon, built the interstate highway system, won world wars, we can do anything if we put our mind to it. I think that there is a good reason to preserve one of our greatest cities, but it is a very vulnerable place. So, if we can't protect it right, then there is a question about inhabiting these kinds of places, certainly the lowest parts of the city.

So far, the plan is we're going to protect it right. And I want to see us actually do that, and I want to see us think big, and have some imagination, and not be stingy about the cost.

And the Corps of Engineers now at least has the plans to do it?

It's a very imperfect branch of government. The bad news is that they are really slow and notorious for being bureaucratic. The good news is that they are in the middle of a risk-assessment process for New Orleans that is being done the right way.

They're using a lot of computer power, and they're running models of a lot of different possible kinds of storms, including global-warming scenarios with enhanced storms. They're trying to figure out what the risk is for different parts of the state, especially New Orleans, under all these different scenarios for 100 years. What's the 100-year worst-case scenario, including global warming as part of the calculation?

What other places do you think need to be protected with that level of intensity?

There is a list of the 10 most hurricane-vulnerable places, and this kind of thing should be done for all of them.

Miami could have a really, really bad hurricane hit it. I don't know about the number of people dying, but the amount of economic loss could be greater than that caused by Katrina. Houston, Tampa Bay, the outer banks of North Carolina -- you just go up the East Coast, even New York, Boston, Maine. There are a lot of bad scenarios.

What's remarkable about the bad hurricanes of 2004 and 2005 especially is that they called to mind these bad scenarios, but none of them were the bad scenarios, except Katrina. And Katrina shouldn't have been, if we had just built the defenses that we thought we had. Katrina didn't hit New Orleans directly. It missed. If it had hit directly, forget about it. Rita was going toward Houston. Frances looked like it might at one point be the one that got to Miami, directly. And Charley looked like it was going to be the one that would go to Tampa, but it didn't.

We've been lucky.

Katharine Mieszkowski

Katharine Mieszkowski is a senior writer for Salon.

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