People have to decide, first of all, how they'd like to live, and how secure they want to be from disaster. After that, scientists can help determine what would be necessary to achieve that.

Recycling helps make people feel involved, and in some cases can be useful. Although you've got to do careful life history studies of what you're recycling. If all you're doing is recycling - if you've got three automobiles, and 10 children, and a 7,000-square-foot dot-com palace and second home up in the mountains that has to be heated - the recycling isn't making much difference.

Your children should have it impressed upon them that their adult life-style will bear very little resemblance to yours and that they should now be acquiring knowledge, skills, values, and tastes that will sustain them in less materially affluent circumstances. On the other hand, the fresh insights and imaginations of your children may help you find a viable future while there's still time.

There are a lot of signs. One of the things that makes me most nervous is the disappearance of the frogs. They're going downhill all over the planet. Frogs are susceptible to all kinds of problems, because they require water to breed and their skin is very porous. Their condition is nerve racking.

I would take even money that England will not exist in the year 2000.

Stanford may be the best university in the world, but you can get all the way through here without knowing where your food came from, without being able to say where we came from, without being able to give a coherent description of why the climate is changing and why we should be concerned about it. So I started teaching a course in human evolution and the environment that's open to all Stanford students, no prerequisites.

With taxes, if they aren't working right, we can change them with a stroke of the pen. It's basically a market-type mechanism. People make their own choices. You run the taxes, and you get the results.