Applying CoolSeal
Photo: Courtesy of Greg Spotts.

On sweltering summer days in Los Angeles, the streets shimmer with hazy heat.

Dark-colored pavement and rooftops dominate urban areas, and they absorb much more heat than natural landscapes. That makes cities hotter than the surrounding countryside, and increases the threats posed by a warming climate.

So L.A. is trying a new cooling tactic: coating asphalt with a reflective, light gray seal.

Spotts: “We have used a coating called CoolSeal on fourteen city blocks, and we found that it’s about ten degrees Fahrenheit cooler on a hot summer day than the adjacent uncoated black asphalt.”

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That’s Greg Spotts with the Los Angeles Bureau of Street Services.

Spotts: “You can actually feel the temperature difference, and we’ve noticed that pets, like dogs on a walk, will prefer to walk on the cool treated part of the pavement because it’s cooler on their paws.”

The next step is to try the product over an entire neighborhood, to see if it has an even greater cooling effect when applied over a large area.

Using a product like this is expensive, so scaling up the initiative would be costly.

But as rising temperatures threaten human health and comfort, cities are looking for creative ways to beat the heat.

Reporting credit: Hannah Breisinger/ChavoBart Digital Media.

Samantha Harrington

Samantha Harrington, Associate Editor of Yale Climate Connections, is a journalist and graphic designer, with a background in digital media and entrepreneurship. "Sam" is especially interested in sharing...