According to a recent study, we can combat global warming just by painting our roofs white. The concept is simple. Rather than absorbing and transferring light energy into heat, white colored roofs increase the reflectivity of the roof’s surface keeping houses and urban environment cooler. According to the study, painting roofs white “reduces their solar heat gain, lowers their temperatures, and avoids transferring heat back into the atmosphere.” All of which reduces global warming.
California has been in on the research for quite a few years now. In 2005 they passed a law requiring all flat roofs to be white, and starting July 2009, they will require all sloped roofs to be at least “cool colored.” (Apparently, a state of white-roofed houses was just to much to bear aesthetically.)
Perhaps it isn’t revolutionary, but it is the little things that count. According to the study in Climatic Change, improving the reflectivity of urban roofs and pavements in warmer climates could offset up to 44 billion tonnes of emitted CO2, the equivalent of “600 million cars off the road for 18 years.” So I ask again: What color is your roof?
