Scott Campbell made the acute realization that sustainable plans of the past have been largely unrealistic, prompting a call for action in favor of redefining sustainability (Campbell, 1). Chicago has responded to this call with a new program known as LEED. LEED is a rating system to measure the level of sustainability of buildings based on the design, operation, construction, and maintenance of green buildings (Green Building). LEED is an acronym for Leadership in Energy and Environmental Design. LEED verifies that buildings, homes, and community centers are built based on safe, green criteria, including water saving, energy efficiency, and above-standard environmental quality. Chicago has 124 LEED buildings thus far, beginning with the first in 2002 after Mayor Richard M. Daley opened the Chicago Center for Green Technology (Grist). 32 of the buildings are municipal structures. The Ogilvie Transportation Center, one of two major transportation hubs in Chicago, is one of the most well-known LEED buildings, with a high level of LEED certification. LEED projects in Chicago mostly center around green roofs and buildings that allow for the mass storage of storm water, which Chicago receives much of. Green rooftops are responsible for four million square feet that cool the city and absorb rain water efficiently. The LEED program has aided Chicago in creating a more sustainable city.