Planet-savers: A new e-book by futurist Alex Steffen argues that cities are the key to environmental salvation

"Steffen is a professional gatherer and disseminator of big ideas, a walking encyclopedia of human betterment. I had a conversation with him a couple of years ago when I was collecting thoughts about what the phrase “city of the future” might realis-tically mean. The upshot was that the glimmering collections of brand-new, boldly shaped towers (think Dubai or Shanghai’s Pudong district)—that have long represented a universal dream of things to come—were finally passé, and the new future would largely be a matter of retrofitting existing cities with systems that made them smarter, more efficient, and more humane. His new book is an expansion of that idea, predicated on the notion that if we don’t rebuild our cities as exemplars of a carbon-neutral lifestyle, the world, literally, will come to an end."