by Brad Jones August 14, 2017 Hard Science
In Brief
Los Angeles will trial GuardTop's gray pavement coating on certain black asphalt streets in an attempt to beat the heat. The coating could lower temperatures by as many as 12 degrees Fahrenheit, helping cut down on A/C usage and therefore lowering the city's greenhouse gas emissions.

In Los Angeles, temperatures that exceed 38 degrees Celsius (100 degrees Fahrenheit) during the summer are not uncommon. Dark pavement can contribute to these higher temperatures, but a new asphalt treatment could reportedly cut street temperatures by as many as 6.6 degrees Celsius (12 degrees Fahrenheit) after just one coat.

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Black asphalt absorbs between 80 and 95 of sunlight, but the “cool pavement” treatment marketed by the California-based sealcoating firm GuardTop reflects it. This could have a big impact on street temperatures and make life more comfortable for people in urban environments.

After successful testing the treatment in parking lots, Los Angeles is ready to be the first major city to put it through its paces on a public road. Officials will monitor how residents react to the new pavement, as well as how long it takes for traffic conditions to soil the gray coloration of the coating.

As Alan Barreca, an environmental science professor at the University of California, Los Angeles, told AFP, “Lower temperatures — due to the pavement — mean less reliance on air conditioning. So, that means less greenhouse gases.”

However, despite the potential advantages of cool pavement coatings, research conducted by the Department of Energy indicated that they do have some drawbacks in terms of the energy and emissions associated with their manufacture, installation, use, and disposal.

By approaching the treatment with caution, rather than rushing into a wide rollout, L.A. can determine whether these drawbacks are outweighed by the benefits and make an educated decision on how to proceed.