National Geographic published an article in its June 2005 issue that links the urban heat island of Atlanta to an increase in the number of thunderstorms the metropolitan area experiences. I have been unable to track it down online, but I did come across some more information on this research on Mace Bentley’s homepage at Northern Illinois University. While green roofs are not mentioned in the article, minimizing storm damage could be another benefit for the technology that is waiting to be quantified.