Today, we share the planet with 7.3 billion other people. By mid-century, we will be approaching 10 billion. And it’s not just our growing numbers, but our expanding affluence. More of the world’s population will be more like us, with increasing access to things like electricity, education, transportation, and health care. We will demand more fuel, more fiber, and more food, and we will consume more of the planet’s ecological space. And though we would wish it were not so, that means less and less for the rest of what we collectively call biodiversity.