How long will economical sources of key minerals last if every human on the planet consumes even half as much as the average rich-world citizen does today? The answer is alarming. According to estimates published a few years ago, the world supply of antimony, to name one metal, could run out in only ten years. Silver could be gone in less than five. And indium could be used up in only a few years, if we don’t find substitutes or start recycling more.
