(p. A2) Since the 1960s, when the global number of people first hit three billion, it has taken a bit over a decade to cross each new billion-person milestone, and so it might seem natural to assume that nine billion humans and then 10 billion are, inexorably, just around the corner. That is exactly what the latest population projections from the U.N. and the U.S. Census Bureau have calculated.
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The U.N.’s projections are the best known. But an alternate set of projections has been gaining attention in recent years, spearheaded by the demographer Wolfgang Lutz, under the auspices of the Wittgenstein Centre for Demography and Global Human Capital at the University of Vienna, of which Mr. Lutz is founding director.
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“There’s two big questions,” Mr. Lutz explains, that determine whether his forecasts or the U.N.’s end up closer to the mark. “First, how rapidly fertility will decline in Africa…. The other question is China, and countries with very low fertility, if they will recover and how fast they will recover.”
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The Wittgenstein forecasts, by contrast, look not only at historical patterns, but attempt to ask why birthrates rise and fall. A big factor, not formally included in the U.N.’s models, is education levels. Put simply: As people, especially women, have greater opportunities to pursue education, they have smaller families.
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The U.N. projects Africa’s population will grow from 1.3 billion today to 3.9 billion by century’s end.
Once education is accounted for, Wittgenstein’s baseline scenario projects Africa’s population will rise to 2.9 billion during that time period. In another scenario from Wittgenstein, which it calls the “rapid development” scenario, the population of Africa will only reach 1.7 billion by century’s end.
Wittgenstein’s phrase “rapid development” is revealing: This isn’t a forecast of doom and decline, but rather one in which health and education simply improve, a world with better human well-being, lower mortality, and medium levels of immigration.
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Wittgenstein’s rapid-development scenario has the global population topping out at 8.7 billion in 2050.
For the full commentary see:
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(Note: the online version of the commentary has the date August 12, 2022, and has the title “THE NUMBERS; Global Population Is About to Hit 8 Billion—and Some Argue It Is Near Its Peak.”)