Ways to Keep LA Cool: City Action on Urban Heat Impacts

Posted by in # Blog, #Keeping LA Cool on March 27, 2015

We don’t have to tell you it’s getting hotter in LA — and temperatures will continue to rise. But does it have to be this way? Is there nothing we can do to derail that linear narrative? The projections are that the Los Angeles region will be 4-5° F hotter in the middle part of this century and the number of extreme heat days (days of 95° F and above) will double –or triple. Are those forecasts unequivocal?

We don’t believe so and neither does LA City Councilmember Felipe Fuentes. In February, Councilmember Fuentes introduced a motion that directs city staff to report on the formation of a “Committee on Cooling and Urban Heat Impacts” with the stated purpose of establishing a cooling target for the city and recommending strategies for achieving that cooling goal.

Some of the heat in LA is caused by a significant urban heat island (UHI) — a dome of heat that sits over our city and causes temperatures to rise in the surrounding areas. The primary cause of this is the large amounts paved surface areas, which absorb radiant energy from the sun and then release that energy as heat, warming the ambient air temperature. UHI contributes on average 4-6° of warming in Los Angeles, but a comprehensive strategy to reduce the UHI could offset some or all of the warming expected in the future due to climate change. In other words, we can continue to enjoy our favorable Southern California temperatures if we begin taking action now. Fortunately, we have already begun to tackle one of the main contributors: roofs. Climate Resolve helped LA become the first city in the U.S. to require cool roofs on all new and rehabbed residential buildings.

The next frontier in reducing heat impacts for our city: we’re working on with the city of LA on cool pavements for our roads. We plan to have pilot projects soon for testing.