Greening roofs in the Bronx has created jobs and communal space for residents while cutting heating/cooling costs, water run-off and 'the heat island effect.'
The Bronx is host to major treatment plants and other industrial buildings that let off toxins. Green roofs have provided residents spaces to come together and enjoy clean air. And the benefits go on: job creation (construction and continued care), reducing water run-off, fighting the 'heat island effect' created by the concrete and asphalt that cover cities, cutting the heating and cooling costs for the building. NYC is even offering tax abatement to green roof structures. When the Bronx beings growing food on these roofs, they will begin to tackle the food desert (areas where fresh food is more than one mile away) problem!
S. Bronx example: http://designtrust.blogspot.com/2008/06/south-bronx-green-roof-tour.html
Inspiring speech about 'greening the ghetto' by Majora Carter: http://www.ted.com/talks/majora_carter_s_tale_of_urban_renewal.html