Human waste is a major public health threat: population growth is taxing even the most advanced sewage systems, and the disease spread by waste kills more people worldwide every year than any other single cause of death. Even in America, 1.95 million people have no access to an indoor toilet. Yet the subject remains unmentionable. The Big Necessity takes aim at the taboo, revealing everything that matters about how people do--and don't--deal with their own waste. George also explores the infrastructure disasters waiting to happen and the potential saviors: from China's five million biogas digesters to the U.S. Army's personal lasers used by soldiers to zap their feces in the field.