Luckily for us, a truly sustainable world already exists. Life on Earth had been in perfect balance for 3.8 billion years, and the secrets to that sustainability are still all around us. Biomimicry is the emulation of nature’s genius in design, engineering, even business. Today, biomimics are learning to repel bacteria like a shark, gather fog like a desert beetle, and circulate resources like a forest. The resulting designs are beautiful, functional, and — not surprisingly — sustainable. Biologist Janine Benyus champions the idea that we should take cues from the natural world, because what better mentor can there be?