Living Roofs are not some crazy new idea, and neither is global warming. In the bay area, there's not a whole lot of residential new construction going on, but every house needs a roof and every roof eventually needs roof-repair or replacement...
So, if you own a home, then you own a roof too! Which gives you have the opportunity to offset some of the urban black-body heat island effect partially generated from what have come to be conventional roofing methods. Your roof is an opportunity to add back a little bit of vegetated footprint/habitat that most roofs take away from our environment.
We can be activists through the choices we make, the actions we take :)
Here are some links to a few great information sources:
Greenroofs 101: http://www.youtube.com/watch?v=pp79mGpomf4
Eaarth Facts & Figures by Bill McKibben: http://billmckibben.com/eaarth/factsandfigures.html
SIMPLE, COST EFFECTIVE OPTIONS:
RoofMeadows - RoofRug: http://www.roofmeadow.com/details-specs-services/details-specs/roofmeadow-roofrug/