And again, Thomas Malthus, a British economist and demographer at the turn of the 19th century, is being recalled to duty. His basic theory was that populations, which grow geometrically, will inevitably outpace food production, which grows arithmetically. Famine would result. The thought has underlain doomsday scenarios both real and imagined, from the Great Irish Famine of 1845 to the Population Bomb of 1968.
But over the last 200 years, with the Industrial Revolution, the Transportation Revolution, the Green Revolution and the Biotech Revolution, Malthus has been largely discredited. The wrenching dislocations of the last few months do not change that, most experts say. But they do show the kinds of problems that can emerge.
The whole world has never come close to outpacing its ability to produce food. Right now, there is enough grain grown on earth to feed 10 billion vegetarians, said Joel E. Cohen, professor of populations at Rockefeller University and the author of “How Many People Can the Earth Support?” But much of it is being fed to cattle, the S.U.V.’s of the protein world, which are in turn guzzled by the world’s wealthy.
