White is the new black
Most people know that if they want to stay cool in the summer, they should wear white, not black. Turns out, the same may apply to roofs and roadways. U.S. Energy Secretary and Nobel Prize winner Steven Chu says painting roofs and roads white is one way to fight global warming.
While it may not be feasible to repaint all the roofs and roads in America, Chu says it makes sense for new projects and some retrofits. He based his opinion on research from Arthur Rosenfeld of the Energy Department’s Lawrence Berkeley National Laboratory. According to a CNNmoney.com story, white roofs have been found to keep buildings cooler, therefore reducing the need for air conditioning. It also decreases the “heat island” effect, which is when a hot urban area makes nearby buildings hot due simply to proximity. White roofs and roads also reflect the sun’s rays into space, which keeps the atmosphere cooler, reported the article.
A white roof could reduce a building’s electric bill by 10 to 20 percent, according to the Energy Department. A “cool” roof or road may not technically be white. The road could use cement-colored asphalt, and a roof could use silver reflective paint or rooftop gardens.
Chu mentioned the idea during a June conference in London as part of a bill to cut greenhouse gases.