Halving The Earth's Population To 4 Billion Is The Best Way To Secure A "Pro-Human" Future, A New Study Argues

That sounds maniacally misanthropic and more than a little eco-genocidal, but let’s explore their case.

The study authors outline their philosophy most clearly in the paper’s conclusions: “Gently ending and reversing population growth and moderating per capita impacts is a pro-nature and pro-human strategy.”

“It will ease pressure on natural resources, lessen poverty in high fertility regions by way of smaller family sizes, reduce pollution, reduce resource and immigration conflicts, and improve quality of life in densely populated areas. A more modest population (e.g., gently easing population to 4 billion by 2200) would protect Earth's natural heritage, including its wild habitats, wild species, and its climate,” they add. 

“Such a world is within our grasp.”

More freedom, not less, is the answer

Fortunately, the researchers aren’t proposing any mass culling of people, nor any malevolent eugenics programmes. 

Instead, they believe it could largely be achieved by giving women family planning services and improving girls' educational opportunities, especially in low-income countries where these privileges remain out of reach for many.

This isn't necessarily a new argument, and there is some data to back this argument up. Once Iran started efforts to promote family planning, the fertility rate (the number of children each woman has) dropped from 4.08 in 1992 to 1.94 in 2001. In South Korea, it fell from 4.07 in 1972 to 1.93 in 1984. For Costa Rica, the decline was slower, but the trend remained the same, falling from 4.16 in 1972 to 1.98 in 2009.

None of this was achieved through coercive or manipulative means. It was achieved by improving reproductive health services and broadening education for girls.

“When women are free to decide how many children to have, fertility rates tend to fall toward replacement level or below, often rapidly,” the study authors write.

Be cautious with fears of overpopulation 

There is, of course, another side to this argument. Discussions about overpopulation often have a nasty aftertaste of ecofascism, or the idea that Homo sapiens are essentially a burden on the natural world and need to be kept in check by an authoritarian fist. 

This sits uncomfortably with some people who believe that the issue isn't with overpopulation, but the governments and corporations that are not doing enough with the resources we already have. For example, there is evidence to show that we can produce enough food to feed everyone on the planet sustainably, but it would take massive changes in priorities and policy.

And modern history holds plenty of reasons to be highly concerned about suggestions of population control. Forced sterilization programs, coercive one-child policies, and colonial-era rhetoric blaming the poor for straining resources have all been carried out under the guise of managing a “healthy” population. 

The researchers behind this study, though, aren't arguing for anything of that sort. On the contrary, their philosophy suggests we should expand choice and freedom, not restrict it, especially for women.

Endless growth on a finite planet

However, they also argue that a global shift in mentality would also be required, away from the pursuit of ever-growing wealth and consumption on a finite planet. This, once again, might be easier said than done.

“Ever-growing wealth and consumption are not ecologically sustainable, and the sooner our societies grapple with this inconvenient truth, the better,” they added.

“Our results suggest that ever-increasing levels of population and resource consumption are not in the interests of future generations, and not the way to sustainability. Helping population growth end and gently and justly reverse, while also moderating per capita impacts, is our best hope to secure a sustainable, desirable future worldwide,” the paper continues.

The new study is published in the journal Sustainable Development.