Unlike the villagers in the fable about the boy who cried wolf, educated American consumers always seem to have the time, the money, and the credulity to pay to hear one more time that we are just about to run out of everything, thanks to population growth.
Troubled as the world may be today, it is incontestably less poor, less unhealthy, and less hungry than it was 30 years ago. And this positive association between world population growth and material advance goes back at least as far as the beginning of the 20th century.
Let us consider — or rather, reconsider — what took place in the 20th century’s “population explosion.” The basic story is well known. A precise count is impossible, but between 1900 and 2000 human numbers almost quadrupled, from around 1.6 billion to more than six billion; in pace or magnitude, nothing like that surge had ever occurred. But why exactly did we experience a world population explosion in the 20th century?