Mathematical biologist Joel E. Cohen examines the question as Earth’s human population heads for seven billion next week, according to a UN estimate.
For millennia, some institutions, including but not limited to the Catholic Church, have viewed increasing populations as signs of increasing wealth and power. Dispelling that notion is proving singularly difficult:
This view was fostered over millenniums, by the pronatalism of the Hebrew Bible, the Roman Empire, the Roman Catholic Church and Arab thinkers like Ibn Khaldun. Mercantilists of the 16th through the 18th centuries saw a growing population as increasing national wealth: more workers, more consumers, more soldiers. Enlarging the workforce depressed wages, increasing the economic surplus available to the king. “The number of the people makes the wealth of states,” said Frederick the Great.
In some cultures such as that of Niger, married couples surveyed say they want a dozen kids or more (or so the fathers said, but even the mothers say they want nine). It may seem insane, but in circumstances of poverty, a dozen kids may assure that parents see enough of them… barely… survive to maturity to assure their own support in later years. So the mental calculations are different no matter what culture a poor family lives in.
Can the Earth support 7, 8, 9, 10 billion people? Those numbers are on their way.
Thomas Malthus was of course wrong:
But just as pronatalism is unjustified, so are the dire — and discredited — prophecies of Thomas Malthus and his followers, who believed that soaring populations must lead to mass starvation.
In fact, the world is physically capable of feeding, sheltering and enriching many more people in the short term. Between 1820, at the dawn of the industrial age, and 2008, when the world economy entered recession, economic output per person increased elevenfold.
I recently read a book on the history of bread, mostly in England. (It seemed like a good idea at the time.) The thing that struck me most is the degree to which the capacity both to grow the grain and to produce the “daily bread” grew by leaps and bounds in the past two centuries. In this small book, there wasn’t an examination of whether the required farming practices and industrial advances were sustainable in the long term, but the ingenuity applied in the short term was remarkable. If I had to guess, I’d guess that the people of the Earth can indeed be fed as their numbers skyrocket… but only if attitudes change. That is the one thing not amenable to new techniques in farming and food production: well-off people are typically as hard-nosed and ungenerous today as they were two centuries ago. So “can Earth’s population be fed” is answerable with a qualified “Yes.” WILL Earth’s population be fed? I don’t have nearly as much confidence in that.
Read Cohen’s article. It’s well worth your time.