In The World Without Us, (St. Martin’s Press, 2007 ) Alan Weisman presents a perspective-expanding look at what would happen on earth if humans were no longer part of the equation. He doesn't go into what happens to all the people, because its really not all about us. Rather, based on his wide-ranging and thorough research, he details how endangered animal populations can recover, how new species may evolve to fill vacated niches, and the likely effects of the time bombs (like nuclear power plants and chemical refineries) we leave behind.
Far from being a work of post-apocalyptic sci-fi, the book actually presents a rather hopeful vision of the planet healing itself. It doesn't (quite) make you hope for our destruction, but gives a clear sense of the negative impact of our collective actions and policies, and hints at how we should be treating the biosphere - assuming we have the time to change our ways.