Countdown: Our Last, Best Hope for a Future on Earth?A powerful investigation into the chances for humanity's future from the author of the bestseller The World Without Us. In his bestselling book The World Without Us, Alan Weisman considered how the Earth could heal and even refill empty niches if relieved of humanity's constant pressures. Behind that groundbreaking thought experiment was his hope that we would be inspired to find a way to add humans back to this vision of a restored, healthy planet