Dirt: The Erosion of Civilizations - Kootenay Local Agricultural Society

thirty to seventy generations. Throughout history, societies grew and prospered
as long as there was new land to plow or the soil remained productive.
Things eventually fell apart when neither remained possible. Societies
that prospered for longer either figured out how to conserve soil, or were
blessed with an environment that naturally refreshed their dirt.
Even a casual reading of history shows that under the right circumstances
any one, or any combination of political turmoil, climatic extremes,
or resource abuse can bring down a society. Alarmingly, we face the
potential convergence of all three in the upcoming century as shifting climate
patterns and depleted oil supplies collide with accelerated soil erosion
and loss of farmland. Should world fertilizer or food production falter,
political stability could hardly endure.
The only ways around the boom-and-bust cycle that has characterized
agricultural societies are to continuously reduce the amount of land needed
to support a person, or limit population and structure agriculture so as to
maintain a balance between soil production and erosion. This presents several
near-term alternatives: we can fight over farmland as the human population
keeps growing and soil fertility declines, maintain blind faith in our
ability to keep increasing crop yields, or find a balance between soil production
and erosion.
Whatever we do, our descendants will be compelled to adhere to something
close to a balance—whether they want to or not. In so doing they
will face the reality that agricultural reliance on fossil fuels and fertilizers
parallels ancient practices that led to salinization in semiarid regions and
soil loss with agricultural expansion from floodplains up into sloping terrain.
Technology, whether in the form of new plows or genetically engineered
crops, may keep the system growing for a while, but the longer this
works the more difficult it becomes to sustain—especially if soil erosion
continues to exceed soil production.
Part of the problem lies in the discrepancy between rates at which civilizations
and individuals respond to stimuli. Actions that are optimal for
farmers are not necessarily consistent with their societies’ interests. Evolving
gradually and almost imperceptibly to individual observers, the ecology
of economies helps define the life span of civilizations. Societies that
deplete natural stocks of critical renewable resources—like soil—sow the
seeds of their own destruction by divorcing economics from a foundation
in the supply of natural resources.
Small societies are particularly vulnerable to disruption of key lifelines,
such as trading relations, or to large perturbations like wars or natural dis-
life span of civilizations 237