By now it's become widely accepted that green roofs can help reduce heating and cooling costs for buildings, and evidence is mounting that they can provide tangible benefits in other areas as well. The latest piece of information comes from New York, for a green roof constructed by ConEdison, the city’s electric utility. The study, conducted in partnership with the Columbia University Center for Climate Systems Research, reveals that green roofs could play a much larger than role than previously expected in helping cities find cost effective ways to deal with excess storm water. That, in turn, provides building owners with new opportunities to participate in urban sustainability planning.