Green Roofs

Looking around the web at green roofs. These are often turf, but sometimes complete gardens, or even used to grow vegetables and herbs. They are insulating, reducing heating costs (and ergo CO2 emissions), absorb pollution and CO2, increases biodiversity, provides habitats for small animals and birds, and make citys look a lot prettier..

Page here about the Chicago green roof programme

another page here by a company that makes green roof with lots of pics