Contributed by Jonathan Shaw
By 2050, somewhere between nine and 11 billion people will be living on the planet. What will everyone eat? More than half the calories consumed by humans come directly from plants, mainly from grains such as rice, wheat, and corn. But agricultural yields of some of these row crops have already plateaued in a third of world. How to feed everyone—without degrading the environment—may be one of the great social problems of the next generation.