Bill Totten's Weblog

Thursday, April 21, 2005


Review of the book by William R Catton, Jr entitled Overshoot: The Ecological Basis of Revolutionary Change (University of Illinois Press, 1980)

by Richard Heinberg

Museletter number 109 (February 2001)

This is quite simply one of the best and most important books I've ever read, and I regret that it took me so many years to discover it. In it, Catton rigorously examines human society as an ecosystem, which is ultimately constrained - as all ecosystems are - by such basic factors as energy, air, and water. His conclusion is familiar, if disturbing:

"Today mankind is locked into stealing ravenously from the future. That is what this book is about. It is not just a book about famine or hunger. Famine in the modern world must be read as one of several symptoms reflecting a deeper malady in the human condition - namely, diachronic competition, a relationship whereby contemporary well-being is achieved at the expense of our descendants. By our sheer numbers, by the state of our technological development, and by being oblivious to differences between a method that achieved lasting increments of human carrying capacity [that is, agriculture] and one that achieves only temporary supplements [that is, reliance on fossil fuels], we have made satisfaction of today's human aspirations dependent upon massive deprivation for posterity."

Human beings have used two basic strategies to increase the carrying capacity of their environments. The first is one that Catton calls the "takeover method":-

"Invading and usurping lands already occupied by others was essentially what mankind had been doing ever since first becoming human. Each enlargement of carrying capacity ... consisted essentially of diverting some fraction of the earth's life-supporting capacity from supporting other kinds of life to supporting our kind. Our pre-Sapiens ancestors, with their simple stone tools and fire, took over for human use organic materials that would otherwise have been consumed by insects, carnivores, or bacteria. From about 10,000 years ago, our earliest horticulturalist ancestors began taking over land upon which to grow crops for human consumption. That land would otherwise have supported trees, shrubs, or wild grasses, and all the animals dependent thereon - but fewer humans. As the expanding generations replaced each other, Homo sapiens took over more and more of the surface of this planet, essentially at the expense of its other inhabitants."

This process was applied at first to other species, then to other humans - societies with denser populations and more powerful weapons taking over the territories of groups with less intensive demands on the environment. This latter strategy has come to its ultimate conclusion with the European takeover of the rest of the planet during the past 500 years.

But once complete takeover was within sight - a situation characterized by a majority of the planet's basic biological productivity having been channeled to human use, and the wealthy few having taken over the majority of the wealth of virtually all people in all cultures - this method could be relied upon no longer. Around 1800, a new ecological strategy began to be implemented: the "drawdown method":-

"Industrialization made use of fossil energy. Machinery powered by the combustion of coal, and later oil, enabled [humans] to do things on a scale never before possible. New, large, elaborate tools could now be made, some of which enhanced the effectiveness of the farming that of course had to continue. Products of farm and factory could be transported in larger quantities and for greater distances. Eventually the tapping of this "new" energy source resulted in the massive application of chemical fertilizers to agricultural lands. Yields per acre increased, and in time acreages applied to the growing of food for humans were substantially increased - first by eliminating draft animals and their requirements for pasture land, but also by reclaiming land through irrigation, et cetera."

The drawdown method resulted in a dramatic, quick increase in the global carrying capacity for humans. The human population did not reach the one-billion mark until 1820; in two centuries, it will have doubled nearly three times. From a biological point of view, this might be seen as a tremendously successful strategy for our species - except for one problem: our newly expanded carrying capacity is based upon the drawdown of finite, exhaustible resources. This is what Catton calls "phantom carrying capacity". Once the fossil fuels begin to run out, carrying capacity will vanish just as quickly as it appeared.

So what to do? His two-decades-old advice is still sound, even though we've lost precious time:-

"Whichever of the two historic approaches we take, either choosing to accelerate drawdown or indulging in additional takeover, our new ecological paradigm enables us to see that eventually we will end up shifting back to the other. Either traditional way, if prolonged, leads to an inhuman future ... not toward the lasting solution of temporarily vexing problems ... For any lasting solution, we must abandon both of these ultimately disastrous methods. Drawdown bails us out of present difficulties by shortening our future. Takeover was of lasting value earlier in human history, but that time is past.

"We must learn to live within carrying capacity without trying to enlarge it. We must rely on renewable resources consumed no faster than at sustained yield rates. The last best hope for mankind is ecological modesty."

Along the way, Catton illuminates ancient and recent history by viewing the human being as an organism seeking to enlarge its niche. For example, he discusses human tool use as prosthesis and Homo sapiens as "the prosthetic animal". He points out that

"... all humans inhabiting other than tropical environments are users of essentially prosthetic devices - clothing ... Likewise, our shoes have served as kind of prosthesis for the hooves we were not equipped with at birth, enabling us to walk additional portions of the uneven face of the earth. The evolutionary and ecological significance of such prosthetic devices has been to facilitate the spread of mankind over a more extensive range than we could have occupied with only the equipment of our own bodies."

Catton notes wryly that "when an airline pilot with thirty-three years of flying experience refers to the familiar act of buckling his cockpit seatbelt as 'strapping a DC-8 to my waist', it is clear that even a modern jetliner can be seen as an elaborate prosthetic device". Moreover, through division of labor, humans have become a species of many niches: "the members of one species discovered ways to behave almost as if they were many different species ... A man or woman with one set of tools could do one sort of job (fill one sort of niche), while a person with a different set of tools could do another sort of job (fill another kind of niche". Thus, "tools could be said to have enabled Homo sapiens to homogenize an otherwise diverse world - making all of it available for human habitation". Unfortunately, the spectacular success of this set of strategic adaptations has led us to lose sight of "the mutuality of impact of organism and habitat upon each other", and of the fact that too much success can sometimes lead to spectacular failure.

Overshoot is a searing, unsentimental assessment of the physical reality of the human condition. Though not for the faint of heart, it is truly brain food for any and all who sincerely wish to understand our predicament so that we can identify the behavioral changes that will lead to collective survival, and initiate them.

Bill Totten


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