Urban heat waves are increasing in frequency, duration and severity, and cities are in desperate need of solutions. One of the simpler emerging fixes is the use of cool pavement coatings. These coatings decrease both the surface temperature of the ground and the air temperature around it, according to a recent study funded by the roofing and waterproofing manufacturer GAF.

The study looked at coated pavement in the Pacoima neighborhood of Los Angeles, one of the hottest areas in the city and the site of the GAF Cool Community Project, an initiative looking for community-wide ways to address urban heat. The pavement coatings came from GAF brand StreetBond and use a technology it calls “Invisible Shade” to reflect the sun’s rays.

Similar to paint, the coatings can be applied to things like roads, playground surfaces, and sidewalks as a clear coat or as a color. This approach could help humans, pets and urban wildlife adapt to our new normal as the planet’s temperature continues to rise.

“Cool pavements are effective under a wide range of weather and environmental conditions,” said Haider Taha, lead researcher on the study and president of the atmosphere research company Altostratus, which helped develop California’s urban heat island index. “They are most effective when needed the most — that is, during the sunnier, hotter summer days. Some of the larger reductions in temperature from the cool pavement coating were observed during a heat wave event, which was an instance when the coatings were most effective.”

“Cool pavement coatings work to increase the reflection of infrared radiation, which impacts heating at both the surface level and higher in the atmosphere,” said Eliot Wall, a senior director at GAF.

In the study, treated pavement surfaces in Pacoima measured 8 to 14 degrees Fahrenheit cooler than non-treated surfaces in the same neighborhood, according to GAF. The air temperature around the coated pavement was also up to 2 degrees Fahrenheit cooler on sunny days and up to 3.5 degrees cooler during a heat wave, Taha said. Even at night, the air was half a degree cooler.

“Reflective pavements can be slightly less influential when there is less direct solar radiation, such as in areas that are constantly in the shade,” Taha said. “But even there, the cooling effect is significant.”

The pavement coating also has a diminished effect when skies are cloudier and there is less heat to reflect in the first place, he added. This is beneficial since it won’t increase the need for artificial heating during the winter.

Read the full article about urban heat islands by Riya Anne Polcastro at Triple Pundit.