Storm expert says climate change may have played a big role in Typhoon Haiyan after all

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Peter Thomson: It will likely be years before the Philippines recovers from the devastation brought by Haiyan, but imagine would might have happened if a storm as massive as that had hit here in the U.S. That’s what Kerry Emanuel has been doing for the last couple of weeks. Emanuel is a Tropical Storm Specialist at MIT. We spoke with them in the days right after the super-typhoon made landfall and since then, he’s been taking a deeper look at the storm and he’s come to some surprising conclusions. Among them, if Haiyan had hit the U.S. instead of the Philippines, it might have been an even worse disaster.

Kerry Emanuel: We don’t get battered as regularly as the Philippines do, nor do we get battered generally by storms as strong as those, so if we had a Haiyan going on in the United States, it would be mayhem.

Thomson: Kerry, are you saying the U.S. is less well-prepared than the Philippines when it comes to these extraordinary storms?

Emanuel: In some respects we are; the Philippines gets hit by five, six, seven, eight typhoons a year, and every so many years, a category five storm. They’re hardened, they’re used to it. We get hurricanes, and sometimes very strong hurricanes, but not as regularly and not quite at the magnitude that we see in the Pacific.

Thomson: Right, so give us a sense of how bigger Typhoon Haiyan was than say, Hurricane Katrina.

Emanuel: Haiyan, as far as we can figure out, was bigger in diameter, and that’s important because it creates a bigger storm surge which is what really kills people. It’s like a tsunami in the middle of a typhoon. It was stronger than Katrina was at its peak magnitude and it moved more rapidly across the country.

Thomson: You’ve got the visual evidence here in this studio; you brought in a satellite photo of Typhoon Haiyan and Hurricane Katrina, both centered over the Gulf of Mexico.

Emanuel: What one of my colleagues did was to take an actual satellite image of Haiyan and simply move it into the position Katrina was when it was at its peak in the Gulf of Mexico, and you can see how much larger Haiyan was and because you can see how cold the cloud tops were compared to Katrina. You can also see that it’s more intense.

Thomson: I’d like to go back to what you told us about the relationship between Haiyan and climate change. You told us that it probably played little or no role in the storm’s development and strength, but it did contribute to storm surge. You’ve revised that assessment; what do you believe now?

Emanuel: What we have done in the meantime was to take one of the models that we normally use to forecast the wind speeds in a storm like that, and rerun it with the temperature and so forth in the ocean that we present in the 1980's, and when we do that, we find that wind speeds are about 10 percent larger now. The destructive potential of a wind storm goes up very quickly with wind speed, so that really corresponds with something like 30 to 40 percent more damage than the same exact event might have done had it occurred in the thermal environment in the 1980's. Now the next step in that is to say, “Why was the thermal environment more favorable?” We haven’t really done that, but the first culprit we look for is the global warming phenomenon.

Thomson: As far as the Philippines and the United States, both of their abilities to deal with typhoons and hurricanes, what do you think the real issue here is?

Emanuel: Well, there are very different problems. The’s pretty hard for typhoons. This is something people ought to understand, but that was so strong that it just smashed everything, so the tragedy is, the government did actually do a reasonable job evacuating people. A lot of the people killed were in evacuation shelters; they just weren’t strong enough. The United States was a different problem because we actively subsidize people to move and build in risky places.

Thomson: Do you feel there are some lessons the U.S. can learn from a place like the Philippines when it comes to preparing for big storms?

Emanuel: I would go beyond that and I would say the entire world has something to learn from all the disasters that occur anywhere in the world. Whenever there’s a disaster, however horrible it is, it’s an opportunity for us to learn from it all kinds of lessons; whether they’re about climate change or about resiliency, how to build buildings, how to prevent people from moving into risky places if possible.

Thomson: For you, as you look at the pictures from places like Taiglobal and Cebu City, what’s the takeaway for you?

Emanuel: The lesson that I came away with is that when you have a truly exceptional event, almost nothing you might have done in preparation for it is going to work. If it’s just too far out of human experience, it’s going to be a tragedy, and how we avoid that is something we all need to put our heads together and think about.

Thomson: Kerry Emanuel, Atmospheric Scientist and Tropical Cyclone Specialist at MIT, thank you for coming in.

Emanuel: Thank you.

Thomson: You can see that image comparing the size and intensity of Typhoon Haiyan and Hurricane Katrina at