... human population and resource use, Overshoot: The Ecological Basis of Revolutionary Change, [in which] human ecologist William Catton asks whether we humans are the same as all other animals. Are we destined for the terrible collapse that has always been the fate of other species that overshoot the underlying carrying capacity of their environment, or are we different enough to plan ahead and manage a population decline? His book and the question it asks are as relevant now as they were in 1980 when the book first appeared. Will we at long last accept the verdict of science?
I have spent the last two days reading and digesting excerpts from the book, found online in "the following chapters: The Tragic Story of Human Success, Dependence on Phantom Carrying Capacity, and Industrialization: Prelude to Collapse." I learned a bit of history that I did not know about the great depression.
Consider the farm population in America. Like almost everyone else, farm families were compelled, by the repercussions of bank failures and the ramifications of general panic, to cut their consumer expenditures. Farmers also often had to allow their land, their buildings, and their equipment to deteriorate for lack of money to pay for maintenance and repairs. Many farms were encumbered by mortgages - mortgages which were foreclosed by banks that now desperately needed the payments farmers could not afford to make. (Bank failures were even more common in rural regions than in major cities.) In spite of all these difficulties, however, the farm population in America ceased declining (as it had been doing) and increased between 1929 and 1933 by more than a million. The long-term trend of movement out of farm niches and into urban niches was reversed during the Great Depression.
Catton uses the lens of ecology to look at human endeavors. Occupational niches are parallel to ecological niches that the process of evolution fills. They are created by a surplus in resources.
Niches everywhere were being constricted by the Depression. However, the urbanizing trend that had been occurring as a result of industrial growth in the cities and from elimination of farm niches by mechanization of agriculture was disrupted by this economic breakdown. At the heart of the reversal was a simple fact: the nature of farming in the 1930s was still such that, whatever else they had to give up, there was still truth in the cliche that "the farm family can always eat". Other (non-food-producing) occupational groups that now had to fall back (like the farmers) on carrying capacities of reduced scope could find themselves in much more dire straits.
The "carrying capacity" is the level of population that the ecosystem can support .
If we read it rightly, then, we can see the differential impact of the Depression upon farm versus non-farm populations as a cogent indicator of the dependence of the total population on previously achieved enlargements of the scope of application of Liebig's law.
Liebig's law states that "whatever necessity is least abundantly available ... sets an environment's carrying capacity." It can be enlarged upon by trade, meaning that the increased carrying capacity is dependent on external sources and and the mechanisms of exchange through which trade happens.
With breakdown of the mechanisms of exchange, various segments of a modern nation had to revert as best they could to living on carrying capacities again limited by locally least abundant resources, rather than extended by access to less scarce resources from elsewhere. Although scope reduction hurt everyone, rural folk had local resources to fall back upon; urban people, in contrast, had so detached themselves as to have almost ceased to recognize the indispensability of those resources. For reasons we shall examine in a moment, economic hard times hit the farms sooner than they hit the cities, but in the final scope-reducing crunch the farmers turned out to have an advantage sufficient to interrupt a clear trend of urbanization.
This is another way of understanding that when oil prices are high enough that transportation of goods are curtailed, we will be dependent upon our local resources. This then begs the question, what can our local resources provide? And the key areas to consider are food, water, employment, medical care and emergency services. If these can't be obtained locally (meaning without relying on a private vehicle to access), then relocating might begin to make sense. The question of where to live will be the topic of my next post.