[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.

We couldn't outspend the fossil fuel industry - they have more money than God.

A price on carbon sufficient to keep 80% of current reserves underground, rebated directly to citizens.

There's no happy ending where we prevent climate change any more. Now the question is, is it going to be a miserable century or an impossible one, and what comes after that.

So far the earth has warmed about a degree Fahrenheit globally averaged. That doesn't seem like an enormous amount but it's unlike what we would have expected twenty years ago.

It was huge mistake to avoid working with the rest of the world because (a) we're the largest source of the problem: 4% of us who are in the U.S. produce 25% of the world's carbon dioxide.

Permafrost in the soil [is melting], in the boreal and arctic areas in the world, and, probably even more alarming in the last six or eight months, the data on what is happening to the ice shelves in Greenland and the west Antarctic has begun to cause people to radically reassess the earlier conviction that those ice shelves were stable on a kind of century-long time scale.