In his widely influential best-seller The World Without Us, Alan Weisman considered how the Earth could heal if relieved of humanity's constant pressures. Behind that groundbreaking thought, the experiment was Weisman's hope that we would be inspired to find a way to add humans back to this vision of a restored, healthy planet - in harmony, not mortal combat, with the rest of nature.

But a sustainable human future seems more in doubt with a million more of us every four 1/2 days on a planet that's not getting any bigger.

Weisman visits an extraordinary range of the world's cultures, religions, nationalities, tribes, and political systems to learn what in their beliefs, histories, liturgies, or current circumstances might suggest it's in their own best interest to limit their growth. The result is a landmark work of reporting: devastating, urgent, and, ultimately, deeply hopeful.

Countdown reveals a way to return our planet and our presence on it to balance: a compelling message that will change how we see our lives and destiny.