Chinese are already more on board than we are. China is the only country that actually discussed in formal government documents how important it is to control the size of your populations if you’re going to limit emissions.

I don't think scientists can dictate from above what we should do, because it's not a matter of scientific decision. If you want to have everybody living like a Beverly Hills millionaire, then 2 billion people might be too many. If we want to have a battery-chicken kind of world, with everybody having an absolute minimum diet, you might be able to support 10 billion.

The main thing is, and of course this is a pedant talking, we should start our education on these issues in kindergarten. Instead of saying, "See Spot run," we ought to say, "See the plant grow in the sun." We ought to explain what runs the weather in the third or fourth grade to start out with.

The drilling idea is spherically senseless - it's senseless from whatever point of view you look at it. It'd take 10 years to bring any oil online, and it would probably go to Japan. It sure wouldn't help gasoline prices here. All the economists say gasoline is still too cheap in the United States anyway. So here we're having this huge debate over offshore drilling that is just straightforward nonsense, which won't surprise you.

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.

It turns out the population issue is an easier thing to deal with than the consumption issue. Some obvious extremes in consumption we can deal with. The standard cure for a stuttering economy is to go out and buy an SUV and three more refrigerators. That's obviously not the way to go.

Overall, The Population Bomb was probably too optimistic. I was writing about climate change - Anne and I actually wrote the book. We discussed whether or not you'd have to take a gondola to the Empire State Building, and that sort of thing, but we didn't know at the time whether the climate change would be in the direction of heating or cooling. We just didn't know enough about it.