I've been trying to convince my academic colleagues that this is a no-brainer. I was watching a documentary on green energy, and someone from Princeton's Carbon Mitigation Porject spoke quite emphatically about the need for efficiency - that the quickest wins are to be had by doing better with available technologies, by operating existing infrastructure more efficiently. They've designed the "wedges game", with physical, wooden wedges that also drives home this point. But our leaders (and the vast majority of us) are missing the point. Why pour money into new technologies when we haven't even started leveraging efficiency opportunities with existing technologies?
We have to optimize to survive.
The Optimizing Web project that I've been working on seeks to leverage agent-based distributed optimization and planning techniques to ensure that we don't just locally do the right thing (which, as things stand now, is the best that we might do - and we aren't even making efforts in that direction) but do the right thing globally. It isn't enough to simply do the greener thing from our local perspective. We need to collaborate to be greener from a broader, more global perspective. What is optimally green from a local perspective might be significantly suboptimal from a more global perspective. Locally suboptimal behaviours might actually do better when we broaden the view.
So (in the spirit of the earlier motto "no taxation without representation") I might say "no carbon mitigation without collaboration".