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Cities struggling with longer, hotter summers tied to climate change may find inspiration on a single block near Boston. From member station WBUR, Martha Bebinger takes us to the Cool Block project in Chelsea, Massachusetts.
MARTHA BEBINGER, BYLINE: Chelsea is an urban heat island. Summer temperatures can be 20 degrees warmer than in leafy suburbs, so there were lots of candidates for this experiment. Boston University associate professor Madeline Scammell helped narrow the list.
MADELEINE SCAMMELL: I actually brought a map to show you some of the hot spots.
BEBINGER: So red - the little red dots mean hotter?
SCAMMELL: Yes.
BEBINGER: Yeah.
Scammell knows because her team placed temperature sensors in trees and on buildings last summer. Today, she's smack in the middle of a red zone, on the chosen block.
SCAMMELL: It is hot. We didn't need the monitors. I mean, I've walked every street in this city, and these are two of the hottest streets. You know when your eyes squint and you're just uncomfortable.
BEBINGER: This particular block heats up a lot of people. There's a Boys and Girls Club and 10 multifamily buildings. The treeless streets and paved backyards bake residents and visitors, putting them at greater risk for heart disease, asthma and stroke. The Cool Block project aims to lower that risk with a package of changes...
(SOUNDBITE OF TRUCK BACKUP ALARM BEEPING)
UNIDENTIFIED PERSON: You good?
BEBINGER: ...Including the arrival of 47 new elm, crabapple, cherry and hawthorn trees.
MARIA BELEN POWER: I'm just going to say a few words, and then we can get planting.
BEBINGER: Maria Belen Power, with the Chelsea-based environmental group GreenRoots, grabs the attention of more than 50 volunteers. Fifteen-year-old Brian Martinez lives just up the street. His boss told him about the project.
BRIAN MARTINEZ: When she said plant trees, I was, like, excited. I was telling my mom, like, oh, I'm going to go plant trees tomorrow.
BEBINGER: Chelsea's director of housing and community development, Alex Train, says getting rid of the black asphalt is next.
ALEX TRAIN: So over the coming month, we're going to be reconstructing the roadway and the sidewalks that we're walking on and installing a light-colored asphalt.
BEBINGER: Corners of the block will become in-ground planters that capture stormwater and support native shrubs. The city is negotiating to install a white roof on the Boys and Girls Club. Train says a white roof on a city elementary lowered the surface temperature there by 20 degrees.
TRAIN: And that reduces surrounding air temperatures upwards of 7 to 10 degrees in the summertime.
BEBINGER: So the white roof and new pavement could help cool the area more quickly. The trees are a longer-term investment in shade. Chelsea's Cool Block will be loaded with pretty much every heat intervention other cities are trying individually. Ariane Middel, who studies heat and urban design at Arizona State University in Phoenix, says it makes sense to concentrate cooling in rising hot spots.
ARIANE MIDDEL: The heat that's the norm here could be elsewhere in the future - right? - because places are getting hotter. So it's important to test these strategies locally because what works in Phoenix may not work in Boston.
BEBINGER: Planting trees and adding a small park to one city block may seem like an ineffective way to tackle climate change, but Maria Belen Power with GreenRoots says it works.
BELEN POWER: That has really been an approach that we take in a lot of our projects. It's sort of piloting small scale and ensuring that we can then replicate those models to really have a much broader impact.
BEBINGER: And doing something now, when climate reports are delivering a lot of doom and gloom, helps her cope.
BELEN POWER: Somedays we feel like - what? - are we really having an impact? Like, is this really going to prevent the climate crisis? And I think that it's not - it's no longer about preventing it, but it's more about protecting the most vulnerable communities.
BEBINGER: Researchers will monitor temperatures during warm seasons for the next few years to see what works.
For NPR News, I'm Martha Bebinger in Boston. Transcript provided by NPR, Copyright NPR.