What you should know – but didn’t know to ask – about overshoot and the ‘population question’

By William Rees | 29 August 2023
The Overpopulation Project

(Image by Vecstock from Freepik)

William Rees explores the nature of humanity’s relationship with energy and the ecosphere, and reaches the unsettling conclusion that a population ‘correction’ is in the offing.

What would you think if someone called you out as a ‘dissipative structure’? Or better, claimed that you were a ‘thermodynamically far-from-equilibrium dissipative structure’? Chances are, you wouldn’t know whether to be offended or to ready yourself to accept congratulations—not many people have ever heard the term ‘dissipative structure.’

This is unfortunate because you actually are a dissipative structure—in fact, the entire human enterprise acts as a single massive dissipative structure. And, it turns out, understanding the workings of dissipative structures shines a whole new light on human ecological overshoot including global heating.

This is just one of the novel arguments in a new paper on the human ecology of overshoot in which I explain why a major population ‘correction’ in this century is inevitable. Simply put, overshoot means that there are too many people consuming and polluting too much; we are using the living Earth faster than ecosystems can regenerate. Thus, the purpose of the article was to make the case, on novel grounds, that: a) the sheer number of humans and the scale of economic activity are undermining the functional integrity of the ecosphere and; b) left unattended, this reality will precipitate a global economic and population contraction – i.e., civilizational collapse—later in this century. The following outlines the core of my argument.

A rather unsettling premise of the piece is that the human eco-predicament is, in many respects, wholly ‘natural’, the product of human evolutionary success gone awry. Innate expansionist behaviours that were advantageous in Paleolithic (pre-agricultural) environments have become maladaptive in today’s globalized industrialized environment. Why is this significant? Because society seems unwilling to recognize that H. sapiens is a still-evolving species subject to the same natural laws and forces affecting the evolution of all living organisms. It is entirely conceivable for modern civilization to be ‘selected out’ by an increasingly hostile environment of our own making. Policies and programs that attempt to ‘fix’ overshoot without attempting to override humanity’s now destructive expansionist tendencies are doomed to fail.

Which brings us back to ‘dissipative structures’—just what are they and where do they fit in? A dissipative structure is a self-producing system that develops and grows by extracting useful energy/matter from its environment and ‘dissipating’ it back into that environment as useless waste. (Isn’t that what your body does?) Dissipative structures form spontaneously in the natural world in response to concentrations or steep gradients of energy/matter. Indeed (and this is important), a dissipative structure can persist only as long as the energy gradient/concentration exists.

I now have to introduce a somewhat peculiar characteristic of human beings. People tend to ‘socially construct’ their own realities—religious doctrines, economic models, political ideologies, scientific theories, etc.—and then live out of their constructs as if they were real. Obviously, a social construct is valid or true only to the extent that it faithfully reflects any aspect of biophysical reality that it purports to represent.

From this perspective, neoliberal economics—the brand of economics currently running the world—is a problematically quirky social construct. Neoliberal models start from the assumptions that the economy and ‘the environment’ are separate systems and that human ingenuity (i.e., technology) can substitute for any product or process of nature. (They certainly make no reference to dissipative structures.) It is an easy leap from the neoliberal paradigm for the world to believe in the perpetual growth of the human enterprise abetted by continuously advancing technology.

But what if the neoliberal construct is totally wrong-headed? What if the human enterprise, far from floating in splendid isolation, is actually a fully-contained, wholly-dependent, growing subsystem of the non-growing ecosphere, as ecological economist Herman Daly consistently argued? Suddenly, the concept of dissipative structures takes on ominous meaning.

Ecologists recognize that living systems exist in nested hierarchies of dissipative structures (picture Russian Matryoshka dolls). Each sub-system in the hierarchy self-organizes and grows by extracting available energy and matter from concentrations in its host ‘environment’ one level up. It processes this useful energy/matter internally to produce and maintain its own complex structure/function and exports—dissipates—useless, degraded energy and material wastes back into its host.

If something is fully dissipated, it is completely disordered; there are no concentrations or gradients, nothing can happen. Physicists refer to this as a state of maximum entropy. All things in nature tend to become more randomly ordered (increase in entropy) unless a source of energy is used to reverse this trend. But this energy always comes from the dissipation of another thing, such as the sun gradually burning itself out, or the food we digest. If the degree of disorder is referred to as entropy, then ‘negentropy’ denotes the degree of order. In effect, living entities (cells, individuals, species, ecosystems) raise themselves from static, disordered near equilibrium states to highly-ordered, functional far-from-equilibrium states but can do so only at the expense of increasing ‘global’ entropy, particularly the entropy of their immediate host systems.

The ecosphere is the highest level in the hierarchy with which we need be concerned—it is the mother of Earthly dissipative structures. The ecosphere produces and maintains itself through photosynthesis by assimilating high-grade solar radiation (negentropy) and by continuously recycling all essential elements and trace nutrients required by its constituent species. In the process, the ecosphere dissipates an equivalent quantity of low grade infra-red radiation (entropy) back into space. While this increases the disorder of its host—the solar system and universe—the impact is negligible.

Not so lower in the hierarchy. Like the ecosphere, the human enterprise is a self-organizing far-from-equilibrium dissipative structure. However, while the ecosphere evolves and maintains itself by ‘feeding’ on an essentially unlimited extra-terrestrial energy source, the sun, and by continuously recycling Earthly matter, the human enterprise grows and maintains itself by ‘feeding’ on the rest of the finite ecosphere and ejecting degraded wastes back into it. This means there are limits to growth: beyond a certain point, the human enterprise can increase in size, internal order and function only by depleting, polluting and otherwise disordering the ecosphere.

Far-from-equilibrium thermodynamics thus provides a simple two-pronged criterion for global sustainability: humanity cannot persistently consume and dissipate more biomass energy/matter (negentropy) than the ecosphere produces, nor generate more waste (entropy) than nature can assimilate (with a generous allowance for the needs of thousands of other consumer species with whom we share the planet).

Is it not clear enough from the above that the neoliberal mantra of perpetual economic growth is inherently pathological? The increasingly demanding human enterprise is functionally positioned to consume the ecosphere from within. Indeed, the accelerating pace of human-induced global ecological change suggests that humanity has already become dangerously parasitic on its planetary host. The increase in Earthly entropy—greenhouse gas accumulations, plunging biodiversity, land/soil degradation, pollution of everything, etc.— is anything but negligible.

Humanity only recently transitioned to playing the maggot to Earth’s apple. With the industrial revolution, humans began seriously to dissipate enormous stocks of fossilized carbon energy—coal, petroleum and natural gas—that had taken tens of millions of years to accumulate. The 1400-fold increase in fossil energy use since just the early 1800s enabled a one hundred-fold increase in real gross world product, a 13-fold uptick in average per capita income (consumption) and provided the food and material resources needed to support an increase in the human population from one to eight billion. It took 250,000 years for anatomically modern humans to reach that first billion but only 210 years—1/1190th as much time—to add seven billion more! Economic and population growth rates that recent generations take to be the norm actually characterize the most anomalous period in human evolutionary history.

The fossil-fueled explosion of the human enterprise is completely consistent with another biophysical concept that almost no one has ever heard of, the maximum power principle (MPP). According to MPP, natural selection favours systems that evolve in ways that maximize their energy intake and power output (i.e., useful energy transformation) for self-maintenance, growth and reproduction. By drawing on a vast supply of ‘extra-somatic’ (i.e., ‘out-of-body’) fossil energy, humanity proved itself an unmatched competitor and the most materially successful vertebrate species ever to walk the earth. Human made stuff (‘anthropogenic mass’) now exceeds the mass of all living biomass on the planet.

But we have a problem. Our success is killing us. The human enterprise is a dissipative structure in overshoot; the production and maintenance of all that ‘anthropogenic mass’ has been at the expense of the entropic degradation of the ecosphere and essential life-support functions. This, in turn, puts humanity between an ominously foreboding rock and a horrific-to-contemplate hard place. The greatest dissipative by-product of burning fossil fuels is carbon dioxide, the major source of anthropogenic climate forcing. Thus, if the world community maintains its growth trajectory and reliance on fossil fuels—which seems to be our default position—people everywhere will suffer some combination of accelerating global heating; marine acidification; runaway biodiversity loss; catastrophic wild-fires, floods and droughts; spreading deserts; crop failures; local famines; collapsed economies; massive unemployment; abandoned cities; mass migrations; civil discord and possible geopolitical turmoil. On the other hand, if we abandon fossil fuels to avoid climate chaos in the absence of adequate substitutes—there are none—the world will suffer energy and other resource shortages; crumbling transportation systems; broken supply lines; shrunken economies; massive unemployment; crop failures; local (possibly global) food shortages; mass migrations; civil discord and possible geopolitical turmoil—and we will still suffer decades of climate disruption. In simplest terms, with abundant energy and continued growth, we will destroy the ecosphere and collapse; with insufficient energy the modern human enterprise must also collapse. Take your pick.

Now you know why a global economic contraction cannot be averted and will almost certainly be accompanied by a major human population ‘correction’. Informed estimates put the long-term carrying capacity of Earth at as few as 100 million to as many as three billion people.

For all the data and details, check out my paper.

Reprinted with permission from Frank Götmark – Project leader of The Overpopulation Project (TORP); Professor, Animal ecology and Conservation Biology, University of Gothenburg.

Sir David Attenborough on overpopulation

Earth currently experiencing a sixth mass extinction, according to scientists | 60 Minutes

Why Overpopulation is Actually a Problem

Mass extinction: what can stop it? | The Economist

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