As heat waves intensify, cities are trying to cool down by painting their streets
STEVE INSKEEP, HOST:
In the middle of a hot day yesterday, I walked to the end of a dead-end street, and I could feel a cool breeze coming through the woods at the end. You can notice many examples of that as you move around. Standing on grass feels cooler than an asphalt parking lot. Standing by a brick wall in the sun is hot. Your surroundings affect the temperature, which matters as climate change intensifies. And that is why Los Angeles is painting the streets. Here's Caleigh Wells from member station KCRW.
CALEIGH WELLS, BYLINE: When a heat wave hits, cities are at a big disadvantage. Unlike forests or water, buildings and roads absorb heat from the sun and radiate it back out, amplifying the heat. Since 2017, the city of Los Angeles has been trying to fight that effect by painting roads with a more reflective paint to bounce the sun's energy back into space.
JONATHAN PARFREY: So the color doesn't look that different.
WELLS: Jonathan Parfrey directs a nonprofit called Climate Resolve that has partnered with the city on this project. He says the color varies street to street because there are a couple different paints they use. But overall, it's not as light as you'd think. And the important part is...
PARFREY: If you brought a laser thermometer out on that street, you would see a distinct difference between traditional asphalt and the newly applied material.
WELLS: Since the city started this program, they've added hundreds of miles of what they call cool pavement.
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WELLS: Ryan Solomon, who lives on a cool street in West LA that was painted last year, says it helps.
RYAN SOLOMON: I thought it was a silly idea until they did one half of the street before they did the other half. And I was walking, and it was like - it felt like a wave, almost, you hit. Still hot, but, like, I think it makes a little bit of a difference.
WELLS: Some of his neighbors, like Carolyn Anderson, aren't so sure.
CAROLYN ANDERSON: I don't think it makes a big difference in terms of temperature.
WELLS: Since these streets were first put in, researchers have been trying to quantify just how much they do help. Kelly Turner is one of them. She's an urban planning and geography professor at UCLA.
KELLY TURNER: They work at doing a specific job, which is to curtail the amount of heat that's absorbed by asphalt.
WELLS: She says that works best in the late afternoon. The street isn't giving off that oven effect because it didn't absorb as much heat during the day. But she says it's not as effective at curbing heat at other times.
TURNER: It does reradiate a certain amount of heat back at any object that is directly above it in the midday hours, from about 11 to 1.
WELLS: That means a person walking at midday might actually feel hotter. So whether or not cool pavements work depend on when they're used. Turner says it might not be great for a school where kids are out playing in the middle of the day, but in a residential neighborhood...
TURNER: Maybe people are at work during the day, and in the evening time they want to go out and walk their dogs. And so, you know, when they're walking, they will feel cooler, and their pet's paws will be cooler. And then it's kind of a really successful implementation of an intervention.
WELLS: Cities are trying other things, too, like planting trees and making roofs more reflective. Turner says that while shade is a much more effective way to keep people cool, these reflective streets have a role to play. And it's not just happening in LA. Phoenix and San Antonio are doing this too. Other cities have been considering it.
KURT SHICKMAN: Las Vegas and Miami, Orlando...
WELLS: Kurt Shickman leads a group that focuses on extreme heat at the Adrienne Arsht-Rockefeller Foundation Resilience Center. They work with governments and experts in different fields to help cities reduce their heat risks. And he says there's growing interest in this tool not just in the U.S., but around the world.
SHICKMAN: In Australia, in southern Europe, in Athens, for example, so it's definitely something that's taking hold.
WELLS: Meanwhile, LA will continue to expand its program, allotting $4 million to make more streets cool in the coming year. For NPR News, I'm Caleigh Wells in Los Angeles.
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