Precautionary Principle in Use
San Francisco has changed the way it does business to ensure environmental protection. The City's Department of the Environment is using the precautionary principle, the idea of looking at how today's choices will effect the environment, and generations to come. San Franciscos' Debbie Raphael and Carolyn Raffensperger, leader in the precautionary principle movement, talk with Tom Henwood about how we can change policy, city by city.