I think that it is impossible to think of a threat to social justice greater than what we are doing to the earth's atmosphere at the moment.

There's no huge mystery. If you dig up huge amounts of carbon, huge amounts of ancient biology, hundreds of millions of year's worth of ancient biology, and flush it into the atmosphere in a matter of decades, then it stands to reason that we're going to have enormous effects, and now we can see those effects all around us.

I'm probably the wrong person to ask. My partner in much of this work [climate movement], who really came up with the divestment campaign with me, Naomi Klein, I think has written powerfully about this.

In the States, I think, the syllogism goes like this: 'free markets solve all problems. Free markets aren't solving global warming, QED global warming is not a problem'. It's not a very good syllogism but it's emotionally comforting if you're in that world.

The laws of Congress and the laws of physics have grown increasingly divergent, and the laws of physics are not likely to yield.

The models that have been constructed agree that when, as has been predicted, the level of carbon dioxide or its equivalent in other greenhouse gases doubles from pre-Industrial Revolution concentrations, the global average temperature will increase, and that the increase will be 1.5 to 4.5 degrees Celsius or 3 to 8 degrees Fahrenheit... In Dallas, for instance, a doubled level of carbon dioxide and other gases like methane, would increase the number of days a year with temperatures above 100 degrees from 19 to 78 each year.

The consumer culture in general has washed over our civilization. For the last 50 years, if you've had a credit card and some access to money, you don't really need neighbors around you. And as a result, they dwindled. The average American has half as many close friends as they did in 1950. Three quarters of Americans don't know their next-door neighbor. They may know their name, but they have no real relationship with them. That's an utterly new place for human beings to find themselves in - I mean, we're a socially evolved primate.