In 50 years, no one will care about the fiscal cliff or the Euro crisis. They'll just ask, "So the Arctic melted, and then what did you do?"

If there's horrible flooding in Pakistan or a horrible heat wave in Texas, we're no longer able to call it an act of God, or a natural disaster, or something like that, the way we could have through all of human history until 35 or 40 years ago.

We've abnegated the Kyoto treaty, we've instituted a voluntary program that's obviously not been working, we've taken every effort to excise references to global warming from official documents, to try to undermine international conferences that work on environmental issues, and on and on and on.

In the States we've had by far the largest demonstrations in the last few years. The largest civil disobedience actions about anything in US history in the last 30 years have all been centred around the climate.

I think communities of faith are extremely important in this question. I think that all faith communities share a common and unusual distinction in our time of being the only institutions left that can posit some goal other than accumulation for human existence. I think that's enormously important because it is that drive for consumption more than anything else that fuels the environmental devastation around us.

Often when I'm on TV, they'll ask what are the three most important things for people to do. I know they want me to say that people should change their light bulbs. I say the number one thing is to organize politically; number two, do some political organizing; number three, get together with your neighbors and organize; and then if you have energy left over from all of that, change the light bulb.

Environmentalism, I'd always been told, was just rich white people.