In an attempt to lower energy use and cool the NY area, a group of green types are painting New York roofs white. The white paint (hope it isn't too toxic) has been applied to 105 roofs so far (1,000,000 sqft), 395,000,000 sqft to go. If all 500 million sqft of roof space in New York is painted white it would be enough to lower the temperature by two degrees Fahrenheit. More importantly, if this big undertaking is completed it would reduce the need for air conditioning by 50%.
Live in NY? Want to paint your roof? details here.