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Smart Surfaces Blog

Heatwaves in CA — How Smart Surfaces Can Help

Deadly heat wave on West Coast over Labor Day weekend

Another brutal heat wave hit the West Coast over Labor Day Weekend. Many areas broke records for hottest-ever September days. August 2020 was the fourth-warmest on record worldwide, and 2020 is set to be the second-hottest or hottest year ever.

That weekend’s round of extreme heat was worse than the last one. The heatwave saw 130-degree temperatures in Death Valley—possibly the highest-ever temperature recorded on Earth in the month of August—and what followed was the largest fire in California history. Five of the six largest fires in California history have burned millions of acres this summer. Firefighters are still fighting those fires, which have grown amid extreme heat and dry weather.

The recent heat waves cannot be divorced from climate change. As California governor Gavin Newsom said at a press conference: “If anyone is wondering if climate change is real, come to California.” Each standalone heat wave is already catastrophic, and as climate change accelerates, they will only become more frequent. Even under low emissions scenarios, the number of extremely hot days and prolonged heat waves will rise. Hotter, drier weather will lead to more droughts and more dangerous, faster-spreading fires. And fires burn forests, releasing even more carbon dioxide into the atmosphere, leading to even faster global warming.

The extreme heat burden will increase energy costs while posing an “exceptional risk” for “deadly heat illness,” the Washington Post reports. Summer heat stress will become more and more common if nothing is done to slow down the rate at which our planet—and especially our cities—are warming. 

Heat waves exacerbate Urban Heat Islands—where high carbon emission rates and widespread dark, impervious surfaces cause cities to be, on average, nine degrees hotter than surrounding rural areas. Altering or replacing those surfaces with reflective roofs and pavements, trees, green roofs, and solar PV is a cost-effective way to cool the atmosphere, lower the risk of heat-related illness or death, and reduce energy bills. 

 
Graph showing higher temperatures in downtown areas than suburban or rural areas.
 

Smart surfaces include reflective roofs and pavements which allow up to 80 percent of sunlight to be reflected away from the surface and back into space. That means much less of the light’s energy is absorbed by the surface as heat, which increases temperatures in buildings and the city air. If reflective/high-albedo surfaces are implemented on a large, city-wide scale, a city can reduce energy costs, increase atmospheric cooling, and both directly and indirectly slow the rate at which carbon dioxide in the atmosphere is increasing. 

Implementing smart surfaces, which can be as simple as painting a dark roof with a reflective coating, will reduce the risk of fires and lower demand on large power grids — thus lowering the chance of unplanned statewide outages, like the rolling blackouts during California’s last heat wave, which impacted millions. A study that simulated city-wide implementation of smart surfaces, including cool, reflective roofs over 40 years in Washington D.C., Philadelphia, and El Paso found cost-benefit ratios of 1 to 8.29, 7.4 and 4.23, respectively. 

Additional investment in smart surfaces — reflective roofs, green roofs, solar PV, porous surfaces, and urban trees — would help solve these pressing problems. Recent heat waves and fires are only the beginning of climate change’s many maladies. With lives and livelihoods at risk, city, state, and national policy-makers can no longer afford to overlook smart surfaces as a necessary change to their surface status quo.