Los Angeles beginning to paint streets all white - will reportedly bring down summer temps by 10 degrees

Los Angeles beginning to paint streets all white - will reportedly bring down summer temps by 10 degrees.

In the race to combat climate change, the city of Los Angeles is employing a surprising new tactic -- covering its streets in a grayish-white coating known as CoolSeal. It's sprayed onto the roadway with trucks, then spread across the surface with squeegees. However, its impact extends far beyond the edge of the pavement.

Los Angeles, like so many other modern cities, is encased in thousands of miles of asphalt. And dark-colored asphalt absorbs between 80 and 95 percent of the sun's rays, heating up not just the streets themselves but the entire surrounding area. So when temperatures in Southern California rise above 100 degrees Fahrenheit, surface temperatures on its asphalt roads can climb to 150. It exacerbates a phenomenon known as the "urban heat island effect," which the EPA says can add up to 22 degrees Fahrenheit to the average air temperature in a city, compared to the surrounding area.

While politicians elsewhere waffle on climate change, officials in Los Angeles are tackling the problem head on with a radical plan to lower the temperature of the city. Mayor Eric Garcetti intends to cut the average temperature in LA by 3 degrees F over the next two decades. As part of that effort, LA streets are getting a new coat of paint.

Cities are prone to overheating, thanks to something called the urban heat island effect. Cities tend to be short on trees, which provide shade, and they are covered with black pavement, which absorbs heat from the sun. Think of how it feels to wear a dark shirt versus a white shirt on a sunny day. A black shirt absorbs light, heating you up. But a white shirt reflects light, keeping you cool.

The average temperature in a city of a million or more people can be more than 5 degrees F hotter than surrounding areas. That extra 5 degrees can turn a hot day from uncomfortable to deadly. As temperatures rise, cities will be an especially dangerous place to be during a heat wave, as sweltering weather threatens heat exhaustion, among other maladies. To protect public health, city officials are going to make the city cooler.

As part of that effort, Los Angeles is coating its roads in CoolSeal, a gray paint that keeps streets and parking lots 10 degrees cooler than black asphalt. Engineers developed the material for military air bases to keep spy planes cool while they rest on the tarmac. This can help them avoid being detected by satellite-mounted infrared cameras, which measure heat.