Coping with only six billion. Matt Ridley

The peak is in sight. Even as the population passes seven billion, the growth rate of the world population has halved since the 1960s. The United Nations Population Division issues high, medium and low forecasts. Inevitably the high one (fifteen billion people by 2100) gets more attention than the low one (six billion and falling). But given that the forecasts have generally proved too high for the past few decades, let us imagine for a moment what might happen if that proves true again.

Africa is currently the continent with the highest birth rates, but it also has the fastest economic growth. The past decade has seen Asian-tiger-style growth all across Africa. HIV is in retreat, malaria in decline. When child mortality fell and economic growth boomed like this in Europe, Latin America and Asia, the result was a rapid fall in the birth rate. For fertility to fall, contraception provides the means, but economic growth and public health provide the motive. So the current slow decline in Africa’s birth rate may turn into a plummet.

If that happens, the low UN estimate could prove more accurate with the world population peaking a little above eight billion and falling to a billion less than today by the end of the century.

Imagine too that agricultural productivity continues to rise. Abundant gas drives down fertiliser prices. Demand from China ensures that new varieties of seeds, better storage and cheap fertiliser reach more African farmers. Perhaps even EU tariff barriers against African produce are lifted and America’s crazy policy of diverting food into motor fuel is reversed.


Read full in The Rational Optimist blog.