NEW YORK, NY April 06, 2009 —The Empire State Building already glows green, for holidays like Saint Patrick's Day. Now, the iconic skyscraper is GOING green, with a major environmental makeover that is expected to cut its carbon emissions by 38 percent. Iain Campbell is with Johnson Controls, which helped plan the retrofit.

CAMPBELL: If all commercial buildings in New York City followed the model developed for this project, there would be a reduction in carbon emissions of over $4.5 million metric tons per annum. Equivalent to that generated by a typical coal fired power plant.

The $20 million upgrade includes replacing all of the building's 6500 windows with insulated glass, and adding extra insulation around radiators. Former President Bill Clinton's Climate Initiative project helped coordinate the makeover. He and Mayor Bloomberg both attended the announcement on the Empire State Building's 80th floor. They say they hope the changes at the famous skyscraper will serve as a model for buildings around the world.