From a Wall Street Journal story by Eric Niiler headlined How Reflective Paint Brings Down Scorching City Temperatures”:

Cities across the U.S. have found relief from this summer’s record-setting heat with the help of technologies that shield roofs, pavement and other surfaces from the sun’s scorching rays.

Some of these technologies have been around for more than a decade but are experiencing greater demand as global temperatures rise. Washington, D.C., for example, has built more than 3,200 green roofs covering 9 million square feet—up from about 300,000 square feet in 2006, according to federal and city officials.