Spraying roofs white helps reflect sunlight and reduces urban heat. Maxppp via ZUMA Press This story was originally published by Grist and is reproduced here as part of the Climate Desk collaboration. The city is a growing paradox.
Humanity needs its many efficiencies: people living more densely and taking up less land—with easy access to decarbonized public transportation—collaborating and innovating as urbanites have always done. But as the climate warms, city dwellers suffer extreme heat more than their rural counterparts as a result of what’s known as the urban heat-island effect . All that concrete, asphalt, and brick absorbs the sun’s energy, accelerating urban temperatures well above those in the surrounding countryside.
In the United States, heat already kills more people than any other form of extreme weather, and nowhere is it more dangerous than in cities. So scientists and urban designers are now scrambling to research and deploy countermeasures, especially in the Southwest —not more energy-chugging air conditioning, but more passive, simple cooling techniques. “Cool roofs,” for instance, bounce the sun’s energy back into space using special coatings or reflective shingles .
And urban green spaces full of plants cool the surrounding air. “In the same way that the urban environment that we have built around us can exacerbate heat, it can also be modified to reduce that heat,” said Edith de Guzman, a researcher at UCLA and director of the Los Ang.