Parking Lot Cool

Parking-Grove-Large

In these recent unseasonably hot days, have you noticed the heat radiating off blacktop? Black asphalt traps heat and releases it back into our cities. “But who said streets had to be black?” asked Ben Schiller, staff writer at Co.Exist. They pointed to Lawrence Berkeley Lab’s showcase of alternative paving surfaces to demonstrate how a parking lot alone can measure 40 degrees cooler if it’s lighter in color. In Los Angeles, you can visit TreePeople’s Center for Communitiy Forestry at our Coldwater Canyon Park headquarters to see this effect in action.

TreePeople’s light-colored Parking Grove demonstrates an environmentally friendly alternative to the traditional asphalt-and-concrete parking lots that blanket much of L.A. We painted over black asphalt with a light color that reflects heat. Naturally, we also planted trees to help shade the area. Trees absorb virtually all of the sun’s energy without radiating heat back into the air. Shade on parked cars can decrease cabin temperatures by 40–50°F and also reduces evaporative hydrocarbon emissions, that is, smog.

The Parking Grove goes further: by incorporating permeable surfaces it helps replenish our region’s groundwater supplies. The gravel in TreePeople’s parking stalls enables rainwater to soak into the ground. Our Parking Grove captures and filters rainwater that we store for irrigating our gardens. We sloped the lot to make the water flow into a centralized, gravel trench drain. From there, the water seeps down into pipes that carry it to our huge underground cistern.

“Lighter surfaces,” reports Schiller, “combined with more vegetation, could impede the formation of smog and reduce energy costs—for example, from air conditioning.” If all the parking surfaces in the world’s 100 largest urban areas were switched to reflective material, it would offset 44 metric gigatons of greenhouse gases that trap heat in the atmosphere and alter our global climate.

Lighter colored asphalt + lots of trees + permeable surfaces = cooler, healthier, more sustainable cities.

Jim Hardie was a full-time actor when he became interested in TreePeople after reading about our weekend plantings in the newspaper. Shortly after he started volunteering, Jim took TreepPeople's first-ever Citizen Forestry training in 1986 and began leading and training our growing volunteer base. A TreePeople board member since 1994, Jim has also donated his time to produce our summer benefit entertainment series for the past decade. Jim currently serves as TreePeople's Director of Park Operations.