We already know that the urban heat island effect can significantly increase temperatures and worsen heat waves, even in neighboring cities. But what can communities do about it?
Cities like Louisville, Kentucky, have already been exploring large-scale tree planting as a way to cut down on heat build up, now LA is unleashing another potential tool against urban warming:
They are painting some of their streets—trial roads in all 15 council districts to be precise—white. (Actually, it’s more like an off-white/gray—but the principle is the same.) By covering blacktop asphalt with a more reflective “cool pavement” treatment, LA Street Services claims they’ll reduce temperatures on a summer afternoon by ten degrees or more. In fact, Curbed Los Angeles reports that a similar scheme in Encino reduced surface temperature on a parking lot by a whopping 25 to 30 degrees.
Of course, immediate localized surface temperatures are probably less important than how the build up of heat on hard surfaces impacts the overall urban microclimate, and associated energy use. And an EPA study on the subject suggests that covering 35% of LAs roads with reflective pavement could reduce average air temperature by a full degree fahrenheit.