Humans Face Major Population 'Correction' This Century, Scientist Warns

Humanity could be on the cusp of a civilizational collapse, according to population ecologist William Rees.

In November 2022, the global population hit 8 billion, according to estimates by the United Nations Population Division. This is more than double what it was in the 1960s. However, while this milestone is a clear indicator of success in public health advancement, it also poses challenges to sustainable development and social and economic progress.

In a recent paper published in the journal World, Rees, from the University of British Columbia, warns of a "major population 'correction'" before this century is out.

"Homo sapiens has evolved to reproduce exponentially, expand geographically, and consume all available resources," Rees writes in the paper. "For most of humanity's evolutionary history, such expansionist tendencies have been countered by negative feedback.

"However, the scientific revolution and the use of fossil fuels reduced many forms of negative feedback, enabling us to realize our full potential for exponential growth," he said.

The United National Population Division has predicted that, over the coming decades, the global population will continue to steadily increase, peaking at around 10.4 billion in the 2080s. Our consumption is also expected to increase. As a result, we are placing an enormous strain on the finite resources of our planet.

Rees describes our excessive consumption as an "overshoot" of what the planet can realistically sustain.

"Humanity has already exceeded the long-term human carrying capacity of the earth," Rees said.

Climate change is just one symptom of this "overshoot," along with disruptions to our planet's nutrient cycles and excessive waste buildup. The question is, will we be able to address these concerns before it is too late?

This is where the second key issue comes in: we are hard-wired to work towards short-term goals. Therefore, Rees argues, we are cognitively ill-adapted to tackle the complexity and long-term consequences of our consumer-based society.

And yet, without action, we will inevitably exhaust the resources our planet is able to provide.

"Unaddressed, these trends may well precipitate both global economic contraction and a significant human population 'correction'—i.e., civilizational collapse—later in this century," Rees said.

Rees concludes with a rather gloomy prediction, viewing widespread societal collapse as inevitable.

"The one-off human population boom is destined to bust. H. sapiens' innate expansionist tendencies have become maladaptive," he said. "However, far from acknowledging and overriding our disadvantageous natural predispositions, contemporary cultural norms reinforce them.

"Arguably, in these circumstances, wide-spread societal collapse cannot be averted—collapse is not a problem to be solved, but rather the final stage of a cycle to be endured...In the best of all possible worlds, the whole transition might actually be managed in ways that prevent unnecessary suffering of millions (billions?) of people, but this is not happening—and cannot happen—in a world blind to its own predicament."