We've had the U.N. for almost 60 years, yet we've never actually made a fundamental list of all the big things that we can do in the world, and said, 'Which of them should we do first?'

The obvious issue is providing clean drinking water and sanitation to every single human being on earth at the cost of little more than one year of the Kyoto treaty.

Of course, the world is full of problems. But on the other hand it's important to get the sense... are we generally moving in the right direction or the wrong direction?

I tentatively believe in a god. I was brought up in a fairly religious home. I think the world is compatible with reincarnation, karma, all that stuff.

The only thing that will really change global warming in the long run is if we radically increase the speed with which we get alternative technologies to deal with climate change.

Surely the biggest problem we have in the world is that we all die. But we don't have a technology to solve that, right? So the point is not to prioritize problems; the point is to prioritize solutions to problems.

I'm a vegetarian, but I don't expect other people not to eat meat.