While the city continues to be a major transportation and distribution center for that industry, it takes a backseat to Chicago?EUR??,,????'???s financial center, the second largest central business district in the U.S. Now when you think ?EUR??,,????'??Chicago,?EUR??,,????'?? think green, because it is the U.S. capital in green roofs. Green Roofs For Healthy Cities (GRHC) reports nearly 300,000 square feet of rooftops cultivated in 2005, up from 200,000 square feet in 2004. The city has 2.5 million square feet of green roof on more than 200 rooftops