White roofs also reduce the heat island effect in an urban area, a potentially critical boon for Atlanta, which famously suffers from a lot of bad-air days. Studies have shown that cities are often three to eight degrees warmer on hot days than outlying rural areas. The effect in Atlanta has been measured as high as 12 degrees. And heat is a major contributing factor to the formation of ozone. – http://www.bizjournals.com/atlanta/stories/2004/02/09/focus3.html

- Austin, TX example – http://www.buildings.com/articles/detail.aspx?contentID=986

- Roofing Savings Calculator – http://www.roofcalc.com/default.aspx