The answer is mixed in Weisman's sprightly and well-considered book. The good news—"Ruins of high-rises echo the love song of frogs breeding in Manhattan's reconstituted streams, now stocked with alewives and mussels dropped by seagulls"—with the uglier—that 1 billion tons of plastic we've produced won't be going anywhere for many thousands of years, and the scenario for oil refineries and nuclear power plants, left unattended, is horrific in the extreme. While nobody reading Weisman's book would consider him a Pollyanna, he refuses to stick to prophecies of eco-doom, being fully knowledgeable that human damage to the earth will likely pale into insignificance when looked at from a geological perspective. In the words of one scientist Weisman quotes, "If the planet can recover from the Permiam, it can recover from the human."
The World Without Us also comes with a nifty website, at which you can not only see the usual publicity material but also a host of multimedia presentations, including one that shows a time-lapse animation of what would happen to a completely untended house over the course of five hundred years. For an audience used to thinking about environmental matters only in terms of this or the next generation or two, seeing exactly how little the human race really means to the planet over such a long stretch of time is humbling. And rightly so.