The world as most of us know it --- big cities, big farms, relatively clean air and water, enough food for all --- will probably come to an end in 50-100 years. That's the punch line of Feed or Feedback: Agriculture, Population Dynamics and the State of the Planet, a 2003 book by A. Duncan Brown, emeritus professor of biology at the University of Wollongong (Australia). Brown writes entertainingly and with passion about long-term issues that will become increasingly important in the next few generations. Those issues mainly revolve around unsustainable resource use by modern large-scale farming.
Professor Brown begins with Nine 'Laws' of Ecological Bloodymindedness:
The First Law For every action on a complex dynamic system, there are unintended and unexpected consequences. In general, the unintended consequences are recognised later than those that are intended.
The Second Law Any system in a state of positive feedback will destroy itself unless a limit is placed on the flow of energy through that system.
The Third Law Any sedentary community, by virtue of its sedentism, will encounter problems of sanitation. The manner in which sanitation is managed will affect the manner in which supporting agriculture is managed.
The Fourth Law For every increment in the agricultural surplus there is a corresponding increment in the volume of urban sewage.
The Fifth Law Stability or resilience in ecosystems requires that all essential reactions within the system function within ranges of rates that are mutually compatible.
The Sixth Law The long-term survival of any species of organism requires that all processes essential for the viability of that species function at rates that are compatible with the overall functioning of the ecosystem of which that species is a part.
The Seventh Law If any species of animal should develop the mental and physical capacity consciously to manage the ecosystem of which it is a part, and proceeds to do so, then the long-term survival of that species will require, as a minimum, that it understands the rate limits of all processes essential to the functioning of that ecosystem and that it operates within those limits.
The Eighth Law Long-term stability or "sustainability" in ecosystems (including agricultural systems) is dependent in part upon the recycling of nutrient elements wholly within the system or upon their replenishment from a renewable source, provided such replenishment is not itself dependent upon a finite source of energy.
The Ninth Law If a population continues to grow exponentially it will eventually consume essential resources faster than they can be replenished. The provision of or access to additional resources will extend the "life" of such resources, and hence the duration of growth of the population, only to a very small extent.
As a sucker for lists, I've gotta like these (even though several of them deserve only to be corollaries or lemmas, not first-class "laws"). In Feed or Feedback Brown unfolds and explores the implications of his "laws". He summarizes the situation when he observes (Chapter 3):
In the course of human cultural evolution, societies were presented, if you like, with two questions. If they answered 'Yes' to Question 1, they proceeded to Question 2. If they answered 'No' to the first question, that was the end of it --- until, in the fullness of time, an answer was imposed by the descendants of those who had answered 'Yes' to both. The first question was, 'Do you want to convert from hunting and foraging to farming?'; the second was 'Do you want to build cities?' Those who answered 'Yes' to both grabbed the tail of the most implacable tiger the world has ever seen. ...
Marshaling his evidence, in impressive detail, takes Brown a few hundred pages. Then he concludes (Chapter 14):
The basis of my argument is this: we have succeeded in producing a system that, by some criteria, has worked very well for a limited period but cannot be 'sustained'. No matter what else we might do, there are two fundamental processes which, if allowed to continue, will certainly lead to the widespread destruction of our habitat, the collapse of civilisation(s), and perhaps the extinction of our species. If the last should happen it will be an impressive achievement --- to the best of my understanding, a world first. Plenty of other species have become extinct, usually because of changes in the physical environment and/or competition from or predation by other species. Extinction caused by a species, not only having the capacity consciously to modify the global environment so profoundly as to make it uninhabitable for itself, but actually going ahead and doing so, has all the essential ingredients of a particularly diabolical Irish joke.
The two basic processes to which I refer are: (1) The 'Vicious Circle', i.e. the positive feedback interaction between population and food supply, and (2) the use of some essential nutrient elements in a way that, for all practical purposes, is irreversible.
The first essential agricultural input to be depleted will probably be phosphate rock; Brown estimates that within 100-200 years its cost will skyrocket. Well before that time, however, Brown's analysis suggests that soil degradation, deforestation, depletion and pollution of water resources, and destruction of fisheries will result in widespread famine and death. It could happen abruptly, when reliance on a few species for food production results in a global ecosystem "... simplified to a level at which it becomes dangerously vulnerable to any of a number of types of stress --- both physical and biological." Or it could be a more gradual collapse, stretching for generations. Brown's best guess is that, if present trends continue, this will begin to be obvious by the middle of the 21st Century.
Prepare to tighten your belt ...
(see also CompassionateCarnivorism (19 Nov 2002), ... )