Ridley: Ehrlich's anti-human legacy

The butterfly biologist turned rock-star eco-pessimist, Paul Ehrlich has died at the age of 93. That in itself is remarkable because in 1970 he forecast that within the coming decade “100-200 million people per year will be starving to death” and “by 1985 enough millions will have died to reduce the earth’s population to some acceptable level, like 1.5 billion people”. Furthermore, by 1980 the life expectancy of the average American would have fallen 42 years as a result of cancer caused by pesticides.

Yet he not only lived more than 50 years longer than 42; he lived to be one of more than 8 billion people in a world where global life expectancy has increased at the average rate of seven hours per day since he forecast it would collapse. Meanwhile, famine has all but gone extinct, with death rates from mass starvation down to a tiny fraction of what they were in the 1960s. Here are the astounding numbers: in the 1960s, 29.7 million people out of a population of 3 billion died in famines that killed more than 100,000 people each. In the 2010s, 1.1 million out of a population of more than 8 billion died in such episodes: a decline of 99% in the death rate.

In short, Ehrlich was wrong. Not, as the New York Times said in its obituary this week, “premature”, but radically, completely, spectacularly wrong. He was wrong as soon as he put pen to paper and went on being wrong for decades afterwards. He shot to fame with a best-selling book in 1968, The Population Bomb, whose prologue dismissed all hope for humankind: “The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now. At this late date nothing can prevent a substantial increase in the world death rate.”

Yet something did prevent that. Even as he wrote these words, the world’s population growth rate was falling. New strains of wheat and rice developed by agronomists like Norman Borlaug were starting to transform the productivity of agriculture and India was on the way to banishing famine and becoming a food exporter within a few short years. The amount of food available has increased faster than population on every continent over the last 60 years even as the land area devoted to farming has begun to fall. As so often with environmental pessimism, Ehrlich’s warning was already out of date when it was made.