There are a lot of things that we could do to minimize what we're doing, but we're not getting back those frogs that I saw that no longer exist.

Humans will eventually become extinct. People treat that as a radical thing to say. But the fossil record shows us that everything eventually becomes extinct.

We're talking really huge global-scale change, and I did not feel that I had the prescription for that kind of action, so I'm going to leave it to the reader.

The Earth is big. There are huge natural forces that have worked over geological time. But it turns out, when you look carefully at the geological time, you can't find anything like us.

I traveled really to amazing places. I went to the Great Barrier Reef, I went to the Amazon, I went to the Andes, to try to bring people stories of sort of what's going on out in the world and bring this issue alive, in a way, and put it out there.

Increasingly developing countries are asking for aid to help deal with the consequences of climate change, which we don't want to give.

You've got to do everything, everything's got to be pointing in the same direction and you've got to really turn this whole economic engine from one that's based on fossil fuels to one that isn't.