A Plan to Cool Down L.A.

On sweltering summer days, dark asphalt soaks up the sun and acts like a secondary heater under our feet. That’s why Los Angeles is pushing a novel plan to cool down the city: Turn the streets a different color. The idea of “cool pavements” has been kicking around City Hall for years, but only recently has it resulted in action on the ground.

Matt Peterson, Los Angeles’s chief sustainability officer, said test applications of a light gray coating known as CoolSeal had shown a 10-degree reduction in heat gain. “It was pretty significant, particularly when you’re talking about asphalt that gets up to 130, 140 degrees,” he said. Climate models suggest that parts of Los Angeles could see roughly three times as many extreme heat days — defined as more than 95 degrees — by midcentury....more