The fight around climate change, which I've spent my life on, is somewhat more difficult than gay marriages because no one makes trillions of dollars a year being a bigot, and that's how much the fossil-fuel industry pulls in pumping carbon into the air. But the principle is the same, I think.

[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.

A spiritual voice is urgently needed to underline the fact that global warming is already causing human anguish and mortality in our nation and abroad, and much more will occur in the future without rapid action.

The fight around climate change, which I've spent my life on, is somewhat more difficult than gay marriages because no one makes trillions of dollars a year being a bigot, and that's how much the fossil-fuel industry pulls in pumping carbon into the air. But the principle is the same, I think.

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.

We also have to engage - and I think this is important - in national politics because there is no way to address questions of this scale in the short time that we have to address them without engaging in real political change.

Especially in recent years, the more and more we understand what we are doing, the more we have the science to tell us what we're doing, the fact that we continue to do it without taking steps to address it strikes me as, among many other things, irreverent in an extreme.