A sustainable future is going to require an awful lot fewer of us. Ecologists reach wildly different estimates regarding the long-term “carrying capacity” of the Earth, but it’s likely to be a lot less than the 8 or 10 billion of us projected for 2100. So how do we get rid of 3/4 of the human race, without war or famine or plague? The best we could hope for, I think, is a “soft landing” of negative population growth for a couple hundred years, but there’s no evidence we’ll be able to arrange that.
A sustainable future is also going to require a much more just society, one with much less income disparity and with necessities guaranteed for everyone. The idea that the rich are going to have to get much much richer in order for the poor to get even a little bit richer is simply not going to work. The incomes of the poorest third of the American population—100 million people—when added together, are now less than the income of the wealthiest 1/100th of 1%, and the trend is getting worse. The average family making $60,000 a year pays a higher fraction of their income in taxes than the average family making $25 million [David Cay Johnston, SFGate.com, 11 Apr. 2004]. Our entire political system has evolved to serve the interests of the few instead of the needs of the many.
For the short term (that hypothetical 200-year “soft landing”), we’re all going to need to tighten our belts a lot. When people talk about globalization, I don’t think most of them realize that it doesn’t mean Indians get to live like Americans; it means Americans get to live like Indians.
And in the long term, we need a completely different economic system. I’m not an economist, but I am a computer scientist, and I know my exponential functions.