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Plant Cover In Cities Could Combat 'Urban Heat Island Effect'

Jul 22, 2019
Originally published on July 22, 2019 7:21 am
Copyright 2019 WXXI News. To see more, visit WXXI News.

RACHEL MARTIN, HOST:

Much of the country is cooler today after a scorching heat wave. Some places across the middle and eastern U.S. have suffered record high temperatures. Cities and suburbs are some of the hottest places because of what is called the urban heat island effect. But there are ways to mitigate that, as Brett Dahlberg of member station WXXI in Rochester reports.

BRETT DAHLBERG, BYLINE: When it's really, really hot out, the last place you probably want to be is in the middle of a mall parking lot.

(SOUNDBITE OF METAL SHOPPING CART CLANKING)

DAHLBERG: But that's exactly where I am with Karl Korfmacher. He's a professor of environmental science at the nearby Rochester Institute of Technology.

KARL KORFMACHER: There's a large expanse of asphalt. And if you look out here, you'll see very little vegetation.

DAHLBERG: Where's the nearest tree?

KORFMACHER: Yeah. That's a long way.

DAHLBERG: Cities and suburbs in the U.S. have lots of this kind of space - expansive blacktops with precious little shade. Korfmacher says these areas are basically big outdoor warming ovens, and that makes hot days even hotter. It heightens the risk for people who are vulnerable to heat-related health problems, like older populations and people who don't have air conditioning at home. And for everyone else, it makes the heat waves even more unbearable. But Korfmacher says it doesn't have to be this way. Even in this desolate parking lot, there's an example of how developers can reduce the effects of urban heat islands.

(SOUNDBITE OF FOOTSTEPS ON BLACKTOP)

DAHLBERG: So we're walking over to - what? What is this?

KORFMACHER: It's just a little vegetation island in the parking lot. You can already see on this that there's moisture, right? Put your hand on it.

DAHLBERG: It's surprisingly cool, actually (laughter).

KORFMACHER: Right.

DAHLBERG: Korfmacher says it's the moisture in the plants that keeps this space cooler than the asphalt. And for more examples of how developers can learn from nature, he leads me down to a quiet spot by the Genesee River, which flows through Rochester.

(SOUNDBITE OF WATER SPLASHING)

KORFMACHER: We got grass all around us. Anytime you have vegetation in an urban setting, you are going to be helping to cool it off a little bit. Shade's also going to sort of cool the building itself. I mean, think about houses that have big shade trees and that are going to cooler, reduces your energy bill.

DAHLBERG: Korfmacher says the closer we can get to having our cities look like natural ecosystems, the better off we'll be in heat waves. Cities across the country are making some progress. Rochester has got plant cover over part of its City Hall to absorb heat. Chicago has started promoting reflective roofing. And in San Francisco, some parking lots are getting resurfaced with new reflective coatings. For NPR News, I'm Brett Dahlberg in Rochester, N.Y. Transcript provided by NPR, Copyright NPR.