Oh, if we all just disappeared. According to The World Without Us, Alan Weisman's strangely comforting vision of human annihilation, the Earth would be a lot better off. In his doomsday scenario, freshwater floods would course through the New York subway system, ailanthus roots would heave up sidewalks, and a parade of coyotes, bears, and deer would eventually trot across the George Washington Bridge and repopulate Manhattan. Nature lovers can take solace in the idea that the planet will thrive once we've finally destroyed ourselves with global warming. But Weisman takes the fantasy one step further: Let's not wait for...