**HOLD FOR RELEASE UNTIL 4 P.M. EST. THIS PHOTO MAY NOT BE POSTED ONLINE, BROADCAST OR PUBLISHED BEFORE 4 P.M. EST ** A ground level rooftop garden covers the top of the loading dock of the new central energy plant in background, at Rush University Medical Center, Tuesday, Nov. 10, 2000 in Chicago. the rooftop garden helps insulate the building and reflect heat. The hospital wants to reduce emmissions by eight percent by 2012 by scrapping three old mechanical sysetems and moving to the new central energy plant for its 27 building campus. (AP Photo/M. Spencer Green)