We're clearly not going to stop global warming at this point. We've already raised the temperature of the planet one degree. We've got another degree in the pipeline from carbon we've already emitted. What we're talking about now is whether we're going to have a difficult, difficult century, or an impossible one.

Absent the net, we certainly couldn't have organized in 190 countries around the world. It's no substitution for face to face interaction - that's why we have "days of action" where people are in real contact with each other - but it's the cheap (and low-carbon) way to do an awful lot of the planning and organizing. And we can build, for $20k, a website as good as one Exxon can build for $20 million.

If you were running a solar company you may be okay - you may be able to keep growing. The question for physics is: Can you grow fast enough to begin to catch up with the damage?

Probably nothing that we have ever managed to do quite equals the basic undermining of the physical stability of the planet on which most of the world's poor people depend.

We've been given a warning by science, and a wake-up call by nature; it is up to us now to heed them.

It's much to the credit of the rest of the world that they have gone ahead and tried to do the Kyoto accords on their own. It makes it unbelievably difficult to do that, for a variety of economic and regulatory reasons, without the participation of the biggest energy user in the world.

You can have a healthy fossil-fuel balance sheet, or a relatively healthy planet