A funny thing happened on the way to the population crisis. The birth rates of some countries started falling dramatically. In fact, the world's population may drop within the next fifty years. In this hour of To the Best of Our Knowledge, re-evaluating the population bomb. Also, a profile of biologist Paul Erlich.

Environmental writer Bill McKibben says it's not just the absolute number of people that creates the population crisis: it's also the environmental impact of each new person in consumer cultures. He tells Steve Paulson that he and his wife have chosen to limit themselves to a single child and suggests that others think about doing the same. McKibben's books include "The End of Nature," and "Maybe One."

Biologist Paul Ehrlich became a celebrity scientist thirty years ago with the publication of his book "The Population Bomb." Ehrlich tells Steve Paulson that it was his work with butterfly populations that got him interested in the human population issue, and that getting people to consume less is harder than getting them to reproduce less. Also, Alan Weisman is the author of "Gaviotas: A Village to Reinvent the World." He tells Jim Fleming about some of the technological innovations that have allowed a thriving community to exist in Colombia on a formerly desolate savannah with bad soil and too much rain. Alan Weisman's new book "Gaviotas: A Village to Reinvent the World," can be previewed at http://www.chelseagreen.com/Gaviotas

Distribution dates:

• week of 08/02/98 - hour 2
• week of 06/27/99 - hour 2