Overshooting the Human Project

Earth by NASA
NASA: public domain image

The first astronauts described Earth with mystical awe as a vulnerable pearl in the barren wastes of space. It had looked the same since before the rise of mammals in the Cenozoic epoch, but suddenly our dirty footprints are all over Mother Earth. Visible from space, they will remain a legacy of the Anthropocene for eons after our species has vanished.

I live in a bubble with a stocked pantry and full gas tank in my car, needing to see a larger reality through the eyes of an ecologist. No book opened them wider to our plight than William Catton’s Overshoot: The Ecological Basis of Revolutionary Change. He published in 1980 with a preface by Stewart L. Udall, former Secretary of the Interior. I had never heard of it until someone I respect said it should be compulsory reading as a key book of the 20th century.

I found a copy with a drab grey cover in the college library after sliding stacks on rollers and knelt down to the bottom shelf. Asking the librarian when the book last went out, he grinned as he stamped it for return in 364 days. I am the first reader in decades. That obscurity is the book’s first message.

The gist is about Earth’s carrying capacity, an expression from ecology and familiar to lemmings. Let me illustrate.

My computer has a large, fixed amount of memory on the hard drive. It seemed limitless at first and for several years I saved thousands of files and software updates without hindrance (equivalent to the exponential rise of animal or human populations). When it ran low on memory, I bought external drives to expand the ‘carrying capacity’ instead of deleting files. I was naïve to think it would never crash by running out of gigabytes. Of course, my solution was to transfer files to a new computer with more memory, but we can’t move humanity after plundering our only planet.

Catton’s book opens with a poignant story in the inaugural year of the Soviet Union (1922). An American journalist visited a Russian community where half the population had died of famine, and the death rate still soared. A lone soldier guarded a huge mound of sacks of grain nearby. When the visitor asked a bearded elder why they didn’t overpower the guard to relieve their hunger, he said the sacks contained seed for growing next season: “We don’t steal from the future.”

The book continues with a history of our species told from an ecological point of view. In the Old Stone Age, hunter-gatherers depended on wild foods from their locality. They could gather more food after inventing spears and bows and arrows, which enabled a slight uptick in their numbers. The emergence of agriculture 10,000 years ago had a bigger impact, especially after the invention of plows. Much later, artificial fertilizers raised the carrying capacity for even more surviving children.

By the Middle Ages, Europe was filling up with people, despite the Black Death. The discovery of the New World and doubling of United States territory from the Louisiana Purchase plus the introduction of hand-held firearms was like opening a valve for European expansion into lands regarded as ‘empty’. In fact, they were already ‘full’ to the extent that indigenous people could manage in the circumstances of earlier technological development. As our numbers surged, logging, farming, mining, and hunting displaced animal life, including many insects (‘the little creatures that run the world,’ E.O. Wilson). For untold generations, people had subsisted on renewable resources from photosynthesis (solar power), but everything changed two centuries ago.

The Industrial Revolution began with inventions like James Watt’s steam engine, replacing human and animal muscle power with fossil energy from photosynthesis millions of years ago and, therefore, non-renewable. Energy is necessary for the engine of a growing human society. Thus began the Age of Exuberance when growth seemed limitless, and temporarily unconstrained by energy, the human population grew even faster. Antiseptic surgery after 1865 and antibiotics in the next century compounded the increase. Calamitous world wars had little impact on the exponential increase toward a plateau at the carrying capacity (logistic curve).

Nations that were formerly self-sufficient overshot their ability to provide enough energy and food for themselves (Britain among the first). They absolutely depended on imports from elsewhere, called ‘ghost acreage’ by Georg Borgstrom (The Hungry Planet).

In the aftermath of World War II, many Americans still believed the myth of limitless growth, which seemed confirmed by the euphoric Green Revolution and Moon landings among other triumphs in science and technology. OPEC’s Oil Embargo in 1973 triggered anxiety, although hopes of discovering limitless energy remained (fusion power is always 30 years in the future!). Governments didn’t question the drawing down of finite resources or have guilty consciences about unborn generations. Business continued as usual for the hallowed growth of GDP under a neo-lib establishment.

It seemed unpatriotic to doubt the American Dream, a project promising to raise all boats around the world (drip-down economics), and yet it didn’t take an ecologist to question it (Death of a Salesman, 1949). But it is always more attractive to be optimistic than the alternative and the privileged don’t willingly yield their entitlements. However, the Age of Exuberance gradually turned sour from mounting evidence of our impact on global warming, species extinction, fisheries, pollution, topsoil erosion, etc.

We now live in an Age of Anxiety in which fear of resource scarcity haunts society. Nativism looks inward, hostile to immigration or sharing our stuff with others (America First!). It presents itself as virtuous while stealing wealth in the ground from the future (the old Russian would shake his head).

Since Catton’s book appeared the world population has grown from 4.5 Bn to nearly 8 Bn. Teeming numbers coupled with an insatiable appetite clamor for fair shares of limited resources. There aren’t enough to be distributed equitably. Even in 1980, he calculated we need ten Earths (and so much more today). The dilemma emerges from our most glorious achievements in technology and medicine plus the momentum of human reproduction that casts us precariously beyond our carrying capacity on a finite planet. The threats are social as well as humanitarian. Long before collapse occurs, the strains and inequities threaten peace and security, especially in open societies and no less in countries where politicians exhort the population to expect unrealistic development goals. These fears were discussed under the buzzword ‘sustainability’ in the Brundtland Report of 1987. Their noble efforts were never going to be equal to the immense challenges of persuading a world inured to its ways.

Catton didn’t live to see coal in retreat or oil and gas slowly replaced by renewable solar and wind energy that provide 22% of US electricity in 2022 (https://www.eia.gov). I expect he would say it is late and then sneer at reports of more fossil fuel use this year.

He called our species Homo colossus for our impact on the biosphere, the thin rind of Earth that supports all life. His book offers no prescriptions, only scenarios ranging from incorrigible optimism to certain calamity. The best hope for humanity and the natural world we love and depend on is resilience until a healthy equilibrium. The process will be alarming if it succeeds, but eventually fewer people could live sustainably, even in a blessed ‘communion’ with other creatures for mutual benefit. The ecotheologian Thomas Berry called this futuristic epoch, the Ecozoic. I always thought the lines in Isaiah about the lion lying down with the lamb absurd, but perhaps it stands as a metaphor. We need dreams for anxious times after peering out of our comfortable bubble.  

By Roger Gosden

British-born scientist specializing in reproduction & embryology. Career as professor & research director spanned from Cambridge to Cornell's Weill Medical College in NYC. Married to Lucinda Veeck Gosden, embryologist for the first successful IVF team in America. Retired early to Williamsburg, Virginia, to write and recover from 'nature deficit disorder'. Currently a visiting scholar at William & Mary. https://en.wikipedia.org/wiki/Roger_Gosden

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