We can use economic instruments to help realize our goals but economics does not tell us what our goals should be.

I think the challenge of climate change in particular is the challenge for us to create and produce new norms for a new kind of world. And that's why I think as important as the issue of climate change is, it's even more important than it seems because if we can't evolve very quickly, new norms to deal with issues like climate change, we're not going to be able to survive in the kind of world we've created. So I think, really, the whole nature of democracy, of governance, of global community and of solving the kinds of problems of the 21st Century are really at stake.

If you're interested in doing something about climate change as we all should be, all of us who care about future people and creatures that will inhabit this world. Then buying a Prius is a good thing but an even better thing would be to be on the streets demanding urgent action from the United States' Congress.

Environmental problems provoke challenges about what kind of world we want, how important we think it is if something is brought about by human action or by brute nature, what we think of the value of human life compared to that of other living things.

In much of the world today there are no more chilling words than "I'm from the United States and I'm here to help you."

I'm a subjectivist about morality.

When it comes to climate change it's all the usual barriers: greed, mendacity, ignorance, short-sightedness and so on, manifest in the extreme power of corporations, the weakness of government, and the indifference of citizens.