The population has exploded

March 25, 2025

In his rambling complaint about forecasting, Stan Glaser overlooks one salient detail: Ehrlich, broadly, got it right. When he wrote The Population Bomb in 1967 there were 3.4 billion humans and today there are 8.2 billion. The bomb exploded by 241%.

However, in 1967 nobody foresaw the success of the Green Revolution in sustaining the boom in numbers. Ehrlich predicted famine, because that was what was happening in overpopulated countries at the time – but not the success in doubling the world food supply.

His book was intended as a caution — as it still is — of the perils of overpopulation. Recent scientific estimates suggest there are about four times more humans than the Earth can support in the long term, at the rate we are currently devouring resources. Belittling those who make such forecasts does nothing to secure the human future.