This year's World Economic Forum at Davos released a report that surprised those still worried about overpopulation. Forget the "Population Bomb." Birthrates are now declining around the world, and the latest concern is the "Grey Tsunami." That's when those over 60 have swamped those under 30, and that moment may be coming sooner than you think. Even the US is moving in that direction, leading New York Times columnist David Brooks to call it, "the slowly aging leader of a rapidly aging world." Will fewer people enjoy longer lives? Will the environment enjoy welcome relief, or will the generations go to war over diminishing resources?