Hurricane Ian's forecast shows the impact of a changed climate
AILSA CHANG, HOST:
All right. Well, this time last year during hurricane season, NPR's Morning Edition asked climate scientist Jim Kossin about whether we should expect more destructive hurricanes. His answer...
JIM KOSSIN: Well, yes. I mean, the trend that we're experiencing that we have seen in the past is projected to continue into the future.
CHANG: That trend specifically is one of slower hurricanes that can linger and dump more rain on a single area. Another trend - a warming planet, which means warmer waters all linked to climate change. Well, let's hear more again from Jim Kossin, senior scientist with The Climate Service, a company that monitors and analyzes climate risk. Welcome.
KOSSIN: Yes. Hi.
KOSSIN: Great to be here.
CHANG: So I want to start with what you told NPR last year - that we could expect more powerful hurricanes and tropical storms going forward. I'm curious. How has this season shaped up so far, in your opinion, in terms of storm intensity?
KOSSIN: Well, of course, it's been a fairly quiet season up until not too long ago. And I think that's an important aspect of climate change in general - is that we're still going to see a lot of year-to-year variability that's completely natural. It could even be as a result of an El Nino, for example. But the season so far - clearly what we're seeing right now with Ian is very unusual, you know, for a storm to be in such a conducive environment for it to become very strong very quickly.
CHANG: Yeah. I mean, one of the bigger fears about the forecast for Hurricane Ian is what's called rapid intensification. I understand this is when hurricane winds increase in a relatively short timespan, right?
KOSSIN: That's correct.
CHANG: Is rapid intensification, as we call it - is that happening more often than it used to?
KOSSIN: Yes, it is. There's mounting evidence and a fair amount of evidence right now that the way that the oceans are warming due to climate change is providing fuel that not just allows the storms to become stronger but to reach that maximum intensity more quickly.
CHANG: OK. And explain exactly how human-fueled climate change is connected to more destructive hurricanes.
KOSSIN: Well, lots of different ways. Some of them are more complex than others. For example, you'd mentioned earlier about them slowing down their forward motion. That was fairly complicated. But we do know that warmer air holds more water vapor. We know that these storms are very good at turning water vapor into rain. So that's increasing. We know that by warming the ocean, we're increasing the fuel for these storms. And consequently, that is basically raising the speed limit. If you were to just drop a storm into any place at any time, the environment will tell you how strong that storm can get. And that's changing. That's increasing. And like so many things in climate science, you can have a small change in the average, but then you get these really large changes out at the ends. For example, a one-degree Celsius warming of the planet leads to a whole lot more heat waves - so a small change in this maximum intensity that they can reach. Suddenly we start to see more and more Category 4 and 5 storms, and those are the ones that do the most damage and create the most mortality.
CHANG: So can you talk about the stakes here? Like, what does this all mean for people who live in the path of storms if these storms get really intense more quickly or they bring more rain than they would have in the past?
KOSSIN: Yeah, there's no question. I mean, the risk is going up. The exposure to the most serious major hurricanes is increasing. One thing that we do have to bear in mind in all of - oh, I'm sorry. One thing that we have to bear in mind in all of this is that if their tracks change - and they do tend to change as well - that you can have changes in your risk due to tracks changing.
KOSSIN: So you could even have potentially a reduction in risk...
KOSSIN: ...In one particular place. So it does get pretty complicated pretty quickly.
CHANG: That is Jim Kossin, senior scientist with The Climate Service. Thank you very much.
KOSSIN: It's a pleasure to be here. Thank you.
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