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MIT Technology Review

Critics blast a proposal to curb climate change by halting population growth

More than 11,000 scientists signed a paper arguing the world needs to stabilize or gradually reduce the global population.

November 6, 2019
A crowd of people.A crowd of people.
A crowd of people.
Unsplash / chuttersnap

More than 11,000 scientists from a broad range of disciplines signed a new editorial declaring a “climate emergency,” but other researchers immediately criticized one of the proposed remedies: halting population growth.

“Still increasing by roughly 80 million people per year, or more than 200,000 per day, the world population must be stabilized—and, ideally, gradually reduced,” reads the piece published in BioScience on Tuesday.

The authors note that effective means of lowering fertility rates include making family-planning services more widely available, improving education for girls and young women, and increasing gender equality.

But rich nations generally already have flat or declining birth rates, so the proposal largely seems directed at fast-growing developing nations in Africa and Asia. Specifically, the UN projects that nine countries will account for more than half of projected growth between now and 2050, including (in descending order) India, Nigeria, Pakistan, the Democratic Republic of the Congo, Ethiopia, the United Republic of Tanzania, Indonesia, Egypt, and the US (where migration is expected to be the main driver of growth).

“A bunch of white people in the developed world saying population should be reduced is the definition of an imperialist framing,” Arvind Ravikumar, an assistant professor of energy engineering at Harrisburg University of Science and Technology, said on Twitter.

Joseph Majkut, a climate scientist and director of climate policy at the Niskanen Center, a think tank based in Washington, DC, says the suggestion is highly problematic from a political standpoint. It feeds directly into the perception among conservatives that “climate science and its conclusions are the product of an ideological movement,” one that prioritizes nature over humans.

A scientific rationale for a smaller world population could also be abused to justify more aggressive tactics of population control, or racist attitudes toward growing parts of the developing world. To some, the proposal drew to mind darker periods in the environmental movement, when various organizations and figures promoted pro-eugenics and anti-immigration views.

The UN projects that global population could grow from around 7.7 billion to 9.7 billion by 2050, and peak around the end of the century at 11 billion.

Fewer people producing less in greenhouse-gas emissions could make some difference in the danger that climate change poses over time. But whether we end up with 9, 10, or 11 billion people in the coming decades, the world will still be pumping out increasingly risky amounts of climate pollution if we don’t fundamentally fix the underlying energy, transportation, and food systems.

Others note inconsistencies in the BioScience paper’s proposed remedies to climate change. Notably, the authors also say the world needs to shift economic priorities away from growth in gross domestic product, and toward meeting basic human needs and reducing inequality.

However, rising GDP levels in many parts of the world reflect declining inequality as poor people in developing nations rise toward the middle class, says Jesse Reynolds, a fellow in environmental law and policy at the University of California, Los Angeles. And at least during the early stages, economic development is often correlated with declines in birth rates, so success at slowing GDP growth may complicate efforts to slow population growth.  

Many prominent names in climate science are conspicuously absent from the list of signatories, and many researchers who did add their names are in fields outside climate and energy. One notable name that does appear is James Hansen, an adjunct professor at Columbia who is considered the father of climate research for his early and influential modeling studies. 

The paper’s other proposals to combat climate change are more widely agreed upon, including aggressively shifting to low-carbon energy sources, cutting short-lived but highly potent climate pollutants like methane, preventing further loss of natural ecosystems and biodiversity, and reducing consumption of animal products.