Heatwaves In LA Are Causing Streets to Be Painted Lighter Colors

Ryan Solomon walks every day, no matter how hot it gets. It's a dog owner's life. Even as the thermometer rises on the first severe heat wave of the year, the temperature doesn't hit him as hard on his street in LA's Palms neighborhood. In Solomon's neighborhood, Vinton Ave., there is gray paint that reflects light. As part of its Cool LA project, the City of Los Angeles is painting some streets lighter and planting more trees in this area. The behavior has been noticed by Solomon, as well as other dog walkers in the neighborhood KCRW spoke with.

The idea seemed silly at first, but then the first half of the street was completed before the second half. While walking, it felt almost like a wave, as if I was on the Metro or something, and I stepped outside and got that cold breeze."

Heat waves are getting hotter, longer, and more frequent across the Southwest due to climate change. In addition to lowering local greenhouse gas emissions, LA is looking at ways of making life in the heat more bearable. Here comes the cool pavement.

Hundreds of miles of mainly concrete and asphalt streets in the past four years were lined with vegetation in Canoga Park, Sun Valley, and Pacoima. The City of LA estimates that when the cool pavement is new, it reduces the surface temperature by as much as 15 degrees Fahrenheit. 

An excellent pavement works by reflecting more of the sun's energy than it absorbs says UCLA Urban Planning and Geography Professor Kelly Turner. The sun's heat is absorbed more by darker colors and reflected more by lighter colors. Midday, however, there may be better news because the heat reflected from the street heats the air above it.

For example, if you wanted to put cool pavement in a playground at a school, you might not get the best use because playgrounds get their most use around noon," Turner suggests. 

As the day progresses, the heat reduction becomes more evident. In the afternoon, the street doesn't radiate stored heat because it does not absorb as much heat during the day. Residents and their pets' paws will feel cooler while walking in the afternoons. The intervention is then implemented very successfully," Turner explains.

According to Turner, planting trees is a far more effective method of cooling neighborhoods than changing the pavement's color. Whatever the surface, she says, it doesn't matter. They'll all be much hotter if exposed to the sun." Palms' gray-washed streets are now lined with saplings, too. It is a pleasure to see them, says Palms resident Carolyn Anderson. No air conditioning and little shade are available to her.

“With the globe warming up, weather patterns being erratic, and climate change impending, shade trees are a no-brainer,” she says. While trees can provide shade, they take years to reach the height needed. Furthermore, they aren't a panacea for drought-ridden landscapes.

As far as our water supply is concerned, we don't have the carrying capacity for that," says Jonathan Parfrey, founder of LA-based climate change nonprofit Climate Resolve. Pavement lighting has the support of Parfrey. With millions of miles of asphalt in California, what do we do? What's the harm in using that? ”

It's great to live in a neighborhood with calm streets. We'll paint them with light and be more reflective this fiscal year. Her neighborhood hasn't cooled yet, but Anderson is optimistic. The lighter paving will make a difference, Anderson says. It is my sincere hope that it does. It is essential for all of us."