Americans, she finds, buy roughly 20 billion garments a year—about 64 items per person—and no matter how much they give away, this excess leads to waste.

As Rob Carlson of the University of Washington points out, if money is to be made selling products made from exhaust gas, then that gas goes from being waste matter to being a valuable resource.

Pet allergies are usually not allergies to fur but allergies to the animal's dead skin, saliva, or waste matter. Regularly cleaning pets can dramatically reduce allergies.