Food security: What crops will feed the world if we run out of farmland?

I Think, Therefore I Yam

When farmland is scarce, will we all eat roots and tubers?

Since Thomas Malthus, alarmists have been pointing out that the world has a finite amount of arable land, whereas its human population keeps growing. Common sense would seem to dictate that eventually there won’t be enough farmland to feed everyone, and catastrophic famine will ensue.

The incredible pace of technological innovation has staved off that eventuality for hundreds of years, seemingly making fools of Malthus and intellectual successors like Paul R. Ehrlich, who in his 1968 book The Population Bomb predicted mass starvation in the 1970s and 1980s. Instead, the green revolution brought high-yielding crop varieties, fertilizers, and pesticides to hungry countries such as Mexico and India, leading to a doubling of food production between 1950 and 2010 with only a 10 percent increase in the amount of farmland. And in the past decade, global population growth has slowed, a deeply encouraging sign (and one that neither Malthus nor Ehrlich envisioned).

Yet the world’s food future may be shakier than ever. It’s not because of the absolute number of people or even the amount of available farmland, but because of what those people eat and how that farmland is used. In short, there’s enough land to feed the world—but not enough to feed the world Big Macs.