An eco-savvy blueprint for tomorrow's megacity points the way to fresh air, clean water and traffic that never jams

摘要

Later this year, for the first time in history, more than half the world will live in cities. And that trend shows no signs of slowing. By 2030, there will be five billion urban souls-up from 3.3 billion today-as the developing world's rural populace migrates to cities, seeking better education and higher-paying jobs.rnThe inevitable result is the megacity, a monster urban infrastructure already roaring to life in Asia and Africa. In China, for example, Dongguan, just a midsize town 20 years ago, now has about seven million residents. Even more extreme, the population of Lagos, the former capital of Nigeria, is expected to hit 24 million by 2015, up from three million in the 1970s.