The Malthusian apocalypse predicted in 1968’s Population Bomb by Paul Ehrlich came and went. There is broad consensus that world population will reach about about 8.5 billion by 2030, from nearly 7.5 billion today. But there’s still a debate whether global population will level off at about 9.5 billion after 2050, or keep rising. And how high?
The new conventional wisdom, dating to 2001 research published in Nature, has been for a stable (if aging) population after 2050. That’s been challenged by U.N. estimates in the 2015 Revision of World Population Prospects that forecast as many as 12.5 billion people by the turn of the century, even with declining birth rates around the world. The report cited continued high fertility in a number of countries: nine countries will account for half the world’s population growth by 2100. And medical advancements will stretch life expectancies.
Now comes new research, published in Science, that suggests that while world population will continue to grow after 2050, it will peak at closer to 11 billion than 12.5 billion. What accounts for the missing 1.5 billion? The earlier U.N forecast doesn’t account for the mitigating effects of climate change, conflict or food shortages.
Such a crash landing could be avoided, or at least better managed, with a decidedly sustainable investment in girls’ education and family planning. Family planning and “higher female education are associated with faster fertility decline,” according to the Science paper. “These suggest that the projected rapid population growth could be moderated by greater investments in family planning programs to satisfy the unmet need for contraception, and in girls’ education.”
That makes Sustainable Development Goal №4 (“Ensure inclusive and equitable quality education”) perhaps the linchpin for the rest of the 17 SDGs. A recent UNESCO report makes clear there’s a lot of catching up to do to make the 2030 deadline. A global plan calls for “the largest expansion of educational opportunity in history” and the financial investment required to achieve it (see, “It’s time to step up progress on universal education”).
Add “sustainable population growth” to the list of returns from investments in family planning and girls’ education. “An intensification of current investments,” the Science paper concludes, “would be required for faster changes to occur.”
This post originally appeared in ImpactAlpha’s daily newsletter. Get The Brief.
Photo credit: Plan International Canada