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 National Academy of Sciences would be unable to give a unanimous decision if asked whether the sun would rise tomorrow.

The mother of the year should be a sterilized woman with two adopted children

So, regarding the time frame, I'm only too willing to admit that my crystal ball, like everybody else's, is cracked. If I could predict precisely, I would have started predicting the stock market and would now be living with a bunch of young women on Bora Bora, having bought it.

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.

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.

There are lots of excellent analysts out there. John Holdren at the Harvard Kennedy School, who was just president of the American Association for the Advancement of Science, has been talking about this stuff for years. There are lots of people out there who understand what’s going on. The problem is, they aren’t much picked up on Fox News.