By 2050, Earth will be home to nearly 10 billion people, a tripled human population during our lifetime. Only 1.8% of the Earth’s surface is arable land that can be used for growing crops, a resource not likely to increase, which means the amount of cropland per person will decline by 20%. In the face of finite resources and a changing climate, Frank Mitloehner, at the University of California, Department of Animal Science, describes why we need sustainable solutions to the 2050 food challenge.