Google "Cradle to Cradle". It's a whole design movement launched by ecological designer William McDonough. William has been given the job of designing eco-cities for 400 million Chinese to move into over the next xyz decades. (I forget how long this project is.) He said something like "They'd use up ALL their coal just baking the bricks for the cities required in China." So he's trying to design eco-cities that use the lay of the land for effective sewerage recycling in a massive, high tech, industrial eco-system where every industrial and biological waste product is recycled back into the city or farming system.
See eclipsenow.blogspot.com/2007/06/reinvent-industry.html for my links to this guy. (Sorry you'll have to copy and paste link manually... I couldn't hyperlink because I'm new here.)
