Overshoot The Ecological Basis of Revolutionary Change
by William R. Catton Jr.
Champagne-Urbana University of Illinois Press
298 pages, $16.95
Originally published in 1980, this reprinted book from The University of Illinois Press synthesizes the disciplines of ecology and sociology and provides a message containing prophetic implications of 16th Century astrologer Michel de Nostradame (Nostradamus). Traditional achievements of exuberance through natural resource depletion are replaced with a new ecological paradigm which allows the reader to understand consequences of irrupting beyond the earth's permanent carrying capacity. Catton provides a concise analysis of Homo sapiens affliction with cornucopian cataracts caused by the supposed cure of technologic progress. This book provides a repeated reminder that human society is merely a strand within the web of life and to ignore the application of ecological principles to daily living habits is to invoke self-inflicted fate.
The author provides a comprehensive assessment of the human predicament by illuminating historical causes of our present overloaded world, applying ecological principles to human situations, and sharpening critical thinking skills to formulate an ecological perspective to thoroughly understand the wages of overshoot. An excellent glossary is provided to assist with ecological terminology used throughout the book.
History reveals that for 2 million years human inhabitants have enlarged human carrying capacity by responding to selection pressures with technologic breakthroughs. Technology historically began with the use of fire and hand tools and progressed into the development of metal tools, fossil fueled machinery, and death control. The Age of Exploration and centuries of colonial expansion displaced other species and diverted biotic resources from the natural community to support the human community. Land which contained trees, shrubs, and grasses to provide food and shelter for the biotic community was converted to crops for human consumption. Agrarian living was replaced with industrial consumption of carboniferous vegetation (coal and oil) which reinforced the myth of limitless resources.
The ecological principle of succession provides the basis for understanding the predicament of the human community. Ecological succession is the replacement of one biotic community by another progressing toward a stable ecosystem. Abandoned cropland no longer tended becomes dominated by grasses followed many years later by shrubs then trees. Similar successional trends occur when freshwater ecosystems such as ponds or lakes turn into a meadow and then a forest. Succession begins as open water with plankton until the depth becomes more shallow by accumulating organic debris (silt) to support submerged vegetation. As depth becomes more shallow and drier, floating and emergent plants along with trees begin to colonize.
Catton applies the principle of succession to the human community. Homo sapiens have preserved their global dominance by migrating from one altered local habitat to a new promised land after exhausting the soil, fish, timber, and mineral deposits. John Steinbeck's 1939 novel, The Grapes of Wrath, depicted the plight of people who migrated from devastated Oklahoma farmlands to California, where the dominant locals were reluctant to share their goods with new arrivals. Earlier, millions of people from overpopulated Europe were on their way to the new world. The inhabitants of the Western hemisphere, the Indians, were not equipped with the numbers or technology to resist European invasion. The Europeans had the power to change everything except the laws of nature. They were not exempt from ecological principles, which would ensure their dominance was less than eternal.
Succession took us from the Age of Exuberance to the age of overpopulation and resource exploitation. Mechanized agriculture provided techniques to out-compete other members of the animal kingdom by consuming the plant kingdom which was followed by two doublings of the earth's population. If man's modification to the web of life with steel plows, mechanical harvesters and synthetic fertilizers and pesticides were to halt, and the modified ecosystems were allowed to revert to their previous condition six human generations ago, then four earths would be needed to support the human population of this earth. Hindsight reveals the human community would have been wise to recognize the precedents which damaged our habitat's capacity to support our species.
Emphasis is placed on the non-exempt status of the human species to population crash. The principles of ecology apply to all species who irrupt beyond the carrying capacity. Bloom and crash occurred to the human population of Easter Island, located in the South Pacific off the coast of Chile. Two canoe loads of Polynesians settled this 45-square mile island and maintained sustenance by raising chickens, gardening, and fishing. Dissension erupted from disagreement about improvement of food production in a finite environment which precipitated genocidal warfare.
Another example of crash is from the animal kingdom. In 1944, twenty-nine reindeer were introduced to St. Matthew Island. By 1963, the herd increased to 6,000, the reindeer carrying capacity was between 1,600 and 2,300, which was 2.6 times what the island could support. Exceeding the carrying capacity caused habitat damage, plummeting the population to 42 reindeer in 1966.
The author summarized the human and mammalian population examples of crash
'We can see from these examples that the agent by which post-irruption crash occurs may be something other than starvation. True, the Canadian water weed in Britain may have died back from exhausting some nutrient, and the reindeer devastated the lichen population upon which they depended for winter forage on St. Matthew Island. But the people of Easter Island began their own crash by conflict, and then inflicted starvation upon the survivors by maliciously disrupting food production activities. On the other hand, a study of an irrupting herd of Sika deer on James Island in Maryland found they were well-nourished and parasite-free at the time of die-off. Their growth was markedly inhibited, and this inhibition was shown by autopsy to be due to physiological disturbances induced by the behavioral stress associated with high population density.
'In drawing lessons for mankind at large from these varied examples, we must first acknowledge that species differences are no protection from the basic pattern. Second, we must recognize that, even with an abundance of food, crash can happen (p.217).'
Adapting to post-exuberant conditions will require a revolutionary orientation to understand and penetrate the root of the human predicament. The new ecological paradigm for adaptation recognizes the following basic ideas
1) Human beings are just one species among many species that are interdependently involved in biotic communities.
2) Human social life is shaped by intricate linkages of cause and effect (and feedback) in the web of nature, and because of these, purposive human actions have many unintended con-sequences.
3) The world we live in is finite, so there are potent physical and biological limits constraining economic growth, social progress, and other aspects of human living.
4) However much the inventiveness of Homo sapiens or the power of Homo colossus may seem for a while to transcend carrying capacity limits, nature has the last word (p. 238).
Catton concludes that the human community is condemned to bet on an uncertain future. Misperception of the human situation will motivate efforts to pursue solutions which make matters worse. An ecological understanding of the human predicament will help avoid constructing "the road to hell paved with good intentions." We must act to ensure the inevitable crash minimizes die-off of the human species. Policies must be developed to diminish global dominance to avoid the fatal practice of stealing from posterity.
This book is a vital contribution to the field of Human Ecology and is a comprehensive reference containing the application of ecological principles to the human situation.