Unsqueamish recyclers are devising innovative uses for extreme castoffs. Worm castings provide the raw material for TerraCycle's natural plant foods, which are packaged in used soda bottles. The dung of Welsh sheep and Sri Lankan elephants, which eat cellulose fibers, has been enlisted as a source of pulp for paper. And the city of San Francisco is testing a way to turn dog droppings into methane for power. What's next, a car that runs on dirty diapers?
(Illustration by Josef Gast)