The idea that China and India will just abandon climate action is not true, because they're doing it for more reasons than we are.

To me, it's more important to take the 60-70% of people who really understand that there's a problem [of climate change] and get some percentage of them active than to try and stamp out the last embers of pre-scientific thought.

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

We're not at the point of trying to stop global warming; it's too late for that. We're trying to keep it from becoming a complete and utter calamity

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.

Especially in recent years, the more and more we understand what we are doing, the more we have the science to tell us what we're doing, the fact that we continue to do it without taking steps to address it strikes me as, among many other things, irreverent in an extreme.

I think [George W.] Bush has done nothing right about global warming.