book excerpt

‘The Long-Term Survival of Our Civilization Cannot Be Assured’

Illustration: Intelligencer.

This story is excerpted from Growth: From Microorganisms to Megacities, by Vaclav Smil (MIT Press, 2019).

Natural growth taking place on the Earth is always limited. The universe may be expanding — and may be doing so (or not) at an accelerated rate — but the planet has finite amounts of elements, it receives and processes a finite amount of energy, and it can support only a finite amount of anthropogenic intervention. The old ocean crust is subducted in deep trenches into the mantle in order to make space for the new crust created by magmatic upwelling at spreading ridges. Orogenic (mountain-forming) uplift is limited by tectonic forces and kept in check by erosion. Organisms differ in their rate of growth, and they follow different trajectories from their origin to their death: Some species follow confined exponential curves, the growth of others fits various S-curves, from symmetrical logistic to more complex functions. The growth of most organisms culminates in mature masses and dimensions: Indeterminate growth ended by an organism’s demise is much less common.

Maturity plateaus of organic growth range from minutes to days for microbes and marine plankton, and from months for annual plants, to decades, centuries, even several thousand years for long-lived trees. Growth of heterotrophs is generally more restricted, with humans outliving all but a few animal species. And while some animals, and many large trees, continue to grow after they reach maturity, their lives end due to predation, infestation, or environmental hazards. Similarly, entire ecosystems gradually evolve the greatest species complexity and the highest photosynthetic productivity to reach their climax status, which may be maintained for extended periods of time (103 to 106 years) before it is destroyed or transformed by climate change (resulting in droughts, fires, or floods), geotectonic upheavals (continental uplift, megavolcanic eruptions, massive earthquakes, tsunami), or impacts of asteroids.

There is no unlimited growth of individual organisms and, in extenso, of all supra-organismic assemblies that range from spatially restricted plant and animal communities (a meadow, a pond) to biomes (boreal forest, tropical rain forest, savanna) covering large parts of continents. And the same confined trajectories (often following near-perfect logistic curves) have marked the growth of inanimate artifacts, be they simple tools or complex machines, energy converters, or cities. But the human population seemed to defy this expected pattern: For generations its growth was hyperbolic — but this phase had to end, and since the late 1960s a new S-curve has been forming.

In contrast, modern civilization has been engaged in a range of activities, and it has institutionalized an array of behaviors, that are driven by the notion of continued growth, be it of specific technical performances, average per capita incomes, or the entire global economy. Growth of individual devices or systems follows confined trajectories, but we are assured that there is no need to worry because perpetual streams of innovations initiate new ascents and keep the escalator rising. A disproportionate share of people in charge of national policies are economists, lawyers, and techno-optimists who do not doubt this narrative and who rarely think about the biosphere’s indispensability for the survival of human societies. Not surprisingly, no government has ever made policies with the biosphere in mind. No government has advocated moderate, subdued economic growth as its priority, even in the world’s most affluent countries, and no major political party has been serious about reconsidering the pace of economic growth.

Given these realities, how strong and how persuasive are the constituencies clamoring to see the moderation, if not the end, of growth — that is, at least, the maintenance of unmistakable performance plateaus? The recent ubiquity of sustainability mantras is not the same thing: Sustainability remains so poorly defined (what are its spatial and temporal scales?) that in too many specific cases we could not be sure if we have already reached it or if it will remain elusive. But what if today’s best-defined stable plateaus are utterly inadequate? What if maintaining many (perhaps most) outputs at today’s level may be quite insufficient to make human existence sustainable for at least as long as we have been around as civilized societies, that is, on the order of thousands of years? How can we be sure that the techno-optimistic escalator will never stop ascending?

How many people are taking seriously an even more unthinkable goal, one that aims not only at setting limits but at having deliberately declining levels and performances (or, in inelegant and inaccurate newspeak, “negative growth” or “degrowth”) as its widely accepted and broadly pursued way of regress. This noun alone illuminates our predicament: Using regress as a qualifier of civilizational achievement, after a long-lasting addiction to progress, seems unreal. This creates an irreconcilable conflict or, more accurately, a challenge for which we have yet to find an effective solution (assuming that one exists).

Continuous material growth, based on ever greater extraction of the Earth’s inorganic and organic resources and on increased degradation of the biosphere’s finite stocks and services, is impossible. Dematerialization — doing more with less — cannot remove this constraint. So far, it has been only a relative phenomenon: We are using less steel or less energy per unit of final product or per desired performance, but as the global population has grown from 1 billion in the first decade of the 19th century to 7.5 billion in 2018, and as rising standards of living have elevated average demand, the aggregate claim on the Earth’s materials and on the biosphere’s resources has grown alongside many phenomena of relative dematerialization. Recognition of these realities leads to decidedly non-Kurzweilian conclusions, although forecasting the timing and the specifics of any possible protracted global economic stagnation, uncontrollable social decline, or a truly catastrophic change remains elusive and counterproductive.

The outlook would be very different if our concerns were limited to just a few kinds of environmental degradation that could be readily managed by technical fixes, that is, by measures akin to our post-1950 successes in treating urban wastewater, preventing emissions of particulates and sulfur dioxide from large stationary sources, and, perhaps most notably, arresting the further rise of stratospheric ozone levels by outlawing chlorofluorocarbons. Unfortunately, concerns are legion, and after decades of efforts we have yet to arrest the growth of all kinds of the most widespread environmental degradations, the first necessary step before reversing such undesirable trends.

That is as true of the depletion of deep aquifers (whose water is withdrawn for mostly highly inefficient crop irrigation) and of deforestation in wet tropics (the harbors of the biosphere’s greatest species diversity) as it is of the globally excessive soil erosion that is, slowly but steadily, diminishing the productive capacity of crop fields; as true of the continuing losses of biodiversity (be it due to deforestation, spreading urbanization, or demand for traditional medicines) as it is of a multifaceted assault on the oceans that ranges from overfishing at the top of the marine food chain to the now ubiquitous presence of microplastics in seawater.

Concerns about rapid global warming — now generally seen as an average tropospheric temperature increase of more than 2°C above the pre-1850 mean — are only the latest, and the most prominent, expression of that irreconcilable conflict between the quest for continuous economic growth and the biosphere’s limited capacity to deal with its environmental burdens. And they are also an excellent demonstration of the limits of readily adopted and affordable technical fixes: Even if the world’s nations fulfilled all of their targets for reducing greenhouse-gas emissions, to which they agreed in Paris in late 2015, the average increase of tropospheric temperature would still rise well above 2°C by 2050, and the latest goal is to keep the anthropogenic rise to no more than 1.5°C, the target that is almost certainly beyond our technical and economic means. But global warming is not the only overarching concern. We do not know how much more of natural land cover and what share of biodiversity we can lose with relative impunity, and if the global population were to survive in relatively large numbers for much longer than its recorded period (that is, longer than 5,000 years), it would almost certainly run into some material restrictions. And we may not succeed in this unprecedented effort to reconcile planetary constraints with human aspirations (or should it be delusions?).

We may not know every detail of doing the right thing, but the direction of the required actions is clear: to ensure the habitability of the biosphere while maintaining human dignity. And sin can be easily left out, and doing the right thing could be motivated by the quest (the moral imperative?) to preserve our species while inflicting the least possible damage on other organisms with whom we share the biosphere. Given the scope of our challenges, adjectives such as radical and bold, to describe the needed vision, and such terms as fundamental shifts and unprecedented adjustments, to characterize the many required changes of policies and everyday practices, are self-evident. But forecasting the state of modern civilization for generations or centuries to come remains an impossible exercise. Even relatively near-term forecasts are bound to fail: No matter how assiduously assembled, a 2018 construct of the world as it might be in 2100 would be, almost certainly, even more misleading than the construct of the year 2018 made in 1936.

But we are on much firmer ground when concluding that the past practices — pursuit of the highest possible economic growth rates, extending the culture of excessive consumption to additional billions of people, and treating the biosphere as a mere assembly of goods and services to be exploited (and used as a dumping ground) with impunity — must change in radical ways. There is nothing new in this perception. This is what Horace wrote two millennia ago in his Satires: “Est modus in rebus, sunt certi denique fines quos ultra citraque nequit consistere rectum” (“There is a mean in things, there are, lastly certain limits on either side of which right cannot be found”). But two millennia later, this is not merely a moral exhortation.
The long-term survival of our civilization cannot be assured without setting such limits on the planetary scale. I believe that a fundamental departure from the long-established pattern of maximizing growth and promoting material consumption cannot be delayed by another century and that before 2100 modern civilization will have to make major steps toward ensuring the long-term habitability of its biosphere.

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‘The Survival of Our Civilization Cannot Be Assured’