Green roofs are known to reduce not only CO2, but also fine particulate matter air pollution. These benefits are especially important given the amount of power generated by coal, lax (by Western standards) industrial emissions standards, as well as the lack of pollution controls on vehicles.
To China's credit they have done the following:
"...include pulling half of Beijing's 3.3 million vehicles off the roads, closing factories in the city and in a half dozen surrounding provinces, and halting most construction in the capital. Some 300,000 heavily polluting vehicles, such as aging industrial trucks, have been banned since July 1."Let's hope that the conditions improve so that the 2008 Beijing Olympics can be a successful display of peaceful competition.