The US state of California has always been considered sunny and in July alone, the air temperature in Los Angeles exceeded 30 degrees Celsius four times. The average monthly indicator for 5 years has grown by 2 degrees and, in desperation, the authorities gave the green light to the most adventurous projects that would save the million-plus city from overheating. Therefore, right now, on a number of streets, black asphalt is being painted white.
City Service L.A. Street Services uses a special coating of asphalt chips, adhesives and polymers that is not actually white, but a very, very light gray. This is important - real, “snowy” whiteness can dazzle drivers. The task is not to reflect the sun's rays, but simply to reduce the heating coefficient, turning dark asphalt into light. The less the city's numerous roads accumulate solar energy, the cooler the surrounding streets will become.
In Canoga Park, 45 km from Los Angeles, after repainting the road, its surface temperature dropped from 33 to 21 degrees Celsius. In a hot, sun-roasted parking lot in Encino, the asphalt has cooled from 72 to 54 degrees. In a passive mode, without additional efforts, the city and state authorities have high hopes for this method, because it is cheap and easy to implement.
The asphalt paint experiment will take place in all 15 Los Angeles constituencies, but not all streets. If deemed successful, the “make dark light” directive would apply to the entire state. For several years now, they have been discussing the idea of repainting all roofs and walls white, similar to buildings in the Middle East. In theory, this will reduce the temperature inside buildings by several degrees at once.