How Climate Change Is Making Epic Storms Like Harvey More Likely

Sep 1, 2017

Harvey was a 1,000-year flood event, according to a new analysis from the University of Wisconsin’s Space Science and Engineering Center. As recovery efforts continue, scientists are studying how much climate change had to do with Harvey’s record-setting rainfall and unusual path over Texas, drawing on data gathered from Hurricane Katrina and Superstorm Sandy.

Here & Now‘s Jeremy Hobson talks with MIT’s Kerry Emanuel about the science of climate change and devastating storms like Harvey.

Interview Highlights

On if there’s anything about Harvey we can attribute to climate change

“There are a couple of things. Its surge was a little bit higher, simply because it was riding on top of an elevated sea level. Fortunately, the surge went into a very unpopulated part of Texas, so we don’t hear much about it. The other thing is that the atmosphere is about 6 percent more humid than it would have been at that time of year at that place [in], say, 1980, because it’s warmer. And those are the two things that we can be fairly certain about.”

“We have long predicted that global warming would allow hurricanes to become more intense, and their surges higher, and also long predicted that they would produce more rain.”

Kerry Emanuel

On whether the rate of recent major storms is a coincidence, or tied to climate change

“We have seen a string of different records, for example Typhoon Haiyan in 2013, and [in the] eastern Pacific, [Hurricane] Patricia of 2015, both broke all-time records for the most intense tropical cyclones. [Superstorm] Sandy was the largest in diameter ever observed in the North Atlantic, [Hurricane] Katrina of 2005 had the largest surge ever recorded in the United States. And now we have Harvey with the largest rainfall ever recorded in a hurricane in the United States. So one begins to wonder, when you have these different metrics being broken all in the last few years, whether we’re seeing something. Now, some of it is consistent with our expectations. We have long predicted that global warming would allow hurricanes to become more intense, and their surges higher, and also long predicted that they would produce more rain.”

On what’s lost by not having a debate about climate change after storms like Harvey

“I think it’s very natural whenever you have an extreme event, people wanna know what caused it. Back in the ’80s, any of these events would have been blamed on El Niño. So one has to be careful. You can’t jump to the conclusion it’s because of climate change. But on the other hand, you can’t embrace the opposite fallacy that there’s nothing to see here. As a scientist you have to sort of look at the facts, try to understand how climate change is warping the probability of these events.”

On the role of discussions about climate change in preparing for future storms

“My community of scientists who study the relationship between hurricanes and climate have been coming together with a consensus on a few things we know — there’s a lot that we don’t know — but one is that storms will rain a lot more as it gets warmer. The other is that surges will be larger, because storms will get a bit more intense and because sea level’s going up. So every community has to tackle this on its own, because every community will be affected differently. Here in Boston we’re actually beginning to contemplate building a seawall across the inner part of Boston Harbor, and in other places it makes sense to talk about vertical evacuation, getting people up inside tall buildings. Every place has its own sort of optimal solution. The point is we all as communities ought to be talking about this.”

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