The world’s population is 7 billion now; and it took thousands of years to build agriculture to its current reach. Developing the capacity to feed another 2 billion in just 35 years appears to be an impossible task: The amount of land already devoted to agriculture has overstressed the environment, and much of what remains is desert, forest or city, not capable of being reclaimed for growing food. It seems that something—the way we raise crops and animals, the chemicals and drugs we use, the foods we choose to eat—has to give.

Well: probably so. But An important and little-discussed part of envisioning the future involves examining our current system of food production, and asking what smaller changes could be made