It's off the charts - and if you don't believe the scientists, ask the insurance industry, the people we pay to analyze risk in our society.

Global warming is no longer a philosophical threat, no longer a future threat, no longer a threat at all. It's our reality.

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.

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?"

All things considered, the internet seems fairly environmentally benign to me. The last stats I saw showed you could do 1,000 Google searches for the gas it took to drive six-tenths of a mile. But the internet can't substitute for real connection and community.

All the signs of incipient activism and uprising, from Tahrir square to Zuccotti Park to [the recent] shutdown of the Internet to protest web censorship. People are getting smart and getting connected.

If one wanted to stigmaitise, that's how one would do it - lots and lots of people saying "we're severing our ties".