Fewer, Richer, Greener

18Simon and Ehrlich: Cornucopianism versus the Limits to Growth

The debate between optimists and pessimists on the future of the human race was, for a time, dominated by two large personalities: Julian Simon (1932–1998), a marketing professor in a business school, and Paul R. Ehrlich (1932–), an entomologist by training. A more unlikely pair of adversaries could hardly be imagined. But, boldly departing from their original fields of expertise, they became a generation’s spokesmen for “cornucopianism,” the idea that resources expand to meet needs, and catastrophism, respectively.

The Cornucopian

Julian Lincoln Simon could be hard to love. He delighted in taking unpopular positions and defended them combatively. He was not an economist, environmental scientist, or demographer. He did not think much of the theories or evidence behind global warming. Astonishingly, he did not want the population explosion to end. His most compelling thought was that more people meant more brains working on solutions to problems—more Newtons, more Edisons, more Einsteins. Describing people as “the ultimate resource,” he advocated for continued population growth. Worrying about what people were going to eat or where they’d live was for somebody else. At least in the recent past, population growth had usually meant better lives.

Simon was right about many things but wrong about an important one: the ability of the world’s population to grow indefinitely without negative consequences. No physical ...