I imagine a certain amount of consumer impulse will be replaced by community connection. You can already see it starting with things like the local food movement.

Delhi is locked in a complete choking smog at the moment - they've had to close schools in one of the world's biggest cities. They have their own reasons for needing to get off fossil fuels fast.

The latest computer modeling I've seen indicates that at mid-century, there might be 150 million people classified as "environmental refugees."

Everybody was cratered after Copenhagen. If the movie had worked the way that it should have, if it had been scripted by Holywood, the world would have come together and addressed the biggest problem it ever had faced and delegates would have embraced each other, and it all would have been a good happy scene instead of the complete farce and debacle that it turned into - maybe in certain ways, an absolute low point for human diplomacy.

[Political actions] has to happen on the local and state level; we have to convince our cities to join the growing number of more than 200 American cities who have signed on to the mayor's climate campaign.

With each month that passes, a solar panel gets 2 or 3 percent cheaper. So while we're holding the fossil fuel industry in check, the engineers in the renewable energy world are undercutting them from the other side.

We don't know exactly where all the tipping points are in the physical world for inescapable damage, but we're clearly reaching close to some of them.