Stop thinking about global warming as a future threat and understand it instead as a present emergency, one that requires a far stronger policy response than we'd imagined.

If we had about 100 years, that sort of slow cultural conversion would be exactly the thing to do. But physics is calling the tune here. We've got to respond to a timetable that physics has set for us.

One degree turns out to be enough to really unhinge all sorts of earth's ecosystems.

The Old Testament contains in many places, but especially in the book of Job, one of the most far-reaching defenses ever written of wilderness, of nature free from the hand of man. The argument gets at the heart of what the loss of nature will mean to us....God seems to be insisting that we are not the center of the universe, that he is quite happy if it rains where there are no people - that God is quite happy with places where there are no people, a radical departure from our most ingrained notions.

If you consider that there are a million people forced out of their homes by Katrina, multiply that by 150, and then stick those people in countries who, as inconceivable as it seems, are less prepared than we were to deal with the whole thing.

In the scientific community, the debate is over, for all intents and purposes, about whether or not the planet is heating and who is causing it. In fact, it's more or less been over since 1995.

I think the best way is to keep stressing, that, as we build out a new energy system, one of the best things about it, if we do it right, will be that it will be more local, more democratic, more distributed, and, in the long run, much more economically sensible.