Just read The World Without Us by Alan Weisman, right on the heels of Blindness by Jose Saramago (Portuguese Nobel prize winner). It's a very interesting combo. In the latter all veneer of "civilization" drops right off when everyone is struck by the same ailment, blindness. Talk about a dog eat dog society! The book is fiction, of course, but makes you think about all our conventions we rely so much on that actually require a lot of "man" power: electricity, government, stores, plumbing, etc.
The World Without Us is an examination of how long it would take the earth to recover from the damage we have already done. He started with Chernobyl and what plants and species jumped in when the nuclear power plant was abandoned. He then extended it to the whole world! It is awesome. He covers everything, including subways (and how long it would take for them to collapse and get filled up with water--not long at all), bridges, cities, etc. In a way it feels good to think that the earth could survive us but of course at times it will take a very very long time: to recover from the chromium and lead we have left in the soil would take 70,000 years, for example. A guy at a party ventured forth a guess of 100 years. Ha! Only one person's lifetime! How naive. He really needs to read this book. We all do!