Every four days there are a million more people on the planet. More people and fewer resources. In this timely work, Alan Weisman examines how we can shrink our collective human footprint so that we don't stomp any more species - including our own - out of existence. The answer: reducing gradually and non-violently the number of humans on the planet whose activities, industries and lifestyles are damaging the Earth. Defining an optimum human population for the Earth is an explosive concept. Weisman, one of the most brilliant environmental writers, has travelled the globe in search of answers, from the settlements of Israel and the plains of Mexico, to the bustling streets of Pakistan and the teeming cities of the UK. In Countdown , Weisman details his encounters with religious leaders, demographers, ecologists, economists, engineers and agriculturalists in what promises to be an international classic.