Los Angeles Tests Whether Lighter Color Streets Will Lower The Temperature

Los Angeles is piloting a project called "Cool Pavement." The city is putting a light grey coating on top of some neighborhood streets in an effort to lower the air temperature.

AILSA CHANG, HOST:

OK. It's August, so here's a safe bet.

GREG SPOTTS: Well, I suspect that if you live on an asphalt street in Oklahoma, in the summer afternoon, it's pretty darn hot on your street.

CHANG: That's Greg Spotts. He doesn't live in Oklahoma, no. But he is the chief sustainability officer of the Bureau of Street Services in Los Angeles. And like many metropolitan areas, LA suffers from what's called the urban heat island effect. That means air temperature inside the city is warmer than in surrounding areas.

DAVID GREENE, HOST:

And so Spotts got to thinking, what if there was some way to cool down the pavement? Could that have a ripple effect and make everything more tolerable?

SPOTTS: If it might be possible to be a little bit less hot when you come home from work and have your house be a little bit cooler because the street is a lighter color, that might be interesting.

GREENE: So LA is piloting what it's calling cool pavement. This involves putting a thin, light gray coating on some streets throughout the city. They found the blocks where it's been applied can remain up to 10 degrees cooler on a summer afternoon. But, we should say, this is a small-scale experiment at the moment.

CHANG: Spotts says they would still have to look at the life-cycle costs - that is, what it takes to make and install the cool product - and balance that with its environmental benefits. He says he hopes this cool pavement idea will spur more innovation.

SPOTTS: Public works is a very slow-changing industry. And the materials we're using in the street are the same materials that were used since World War II. So you can imagine if we can innovate with a climate lens, that could potentially have a tremendous impact in every city and town across the country.

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