City Rooftops: Paint Them White Or Plant Them With Green? — New Study
Cities are real climate hot spots and their rooftops, in particular, absorb heat and run up energy use.
Previous studies have indicated that painting roofs white can be a low tech way to reduce global warming by reflecting the sun’s rays back into space and Prof Steven Chu, the U.S. Energy Secretary, has been heralding the idea.
Now researchers have attempted to quantify the benefits of covering urban rooftops with plants. The scientists found that replacing traditional roofing materials with ‘green’ in an urban area the size of Detroit with a population of about one-million, would be equivalent to eliminating a year’s worth of carbon dioxide emitted by 10,000 mid-sized SUVs and trucks. Their study is the first to examine the ability of green roofs to sequester carbon that may impact climate change and the findings are scheduled to appear in the journal Environmental Science & Technology.