Lesson One - Population, Urbanization, and the Environment

The Tragedy of the Commons

You might have heard the expression “the tragedy of the commons.” In 1968, an article of the same title written by Garrett Hardin describes how a common pasture is ruined by overgrazing. But Hardin was not the first to notice the phenomenon. Back in the 1800s, Oxford economist William Forster Lloyd looked at the devastated public grazing commons and the unhealthy cattle subject to such limited grazing, and saw, in essence, that the carrying capacity of the commons had been exceeded. However, since no one held responsibility for the land (as it was open to all), no one was willing to make sacrifices to improve it. Cattle grazers benefited from adding more cattle to their herd, but they did not have to take on the responsibility of the destroyed lands that were being damaged by overgrazing. So there was an incentive for them to add more head of cattle, and no incentive for restraint.

Satellite photos of Africa taken in the 1970s showed this practice to dramatic effect. The images depicted a dark irregular area over 300 miles around. When seen from above, there was a large fenced area, where plenty of grass was growing. Outside the fence, the ground was bare and devastated. The reason was simple: the fenced land was privately owned by informed farmers who carefully rotated their grazing animals and allowed the fields to lie fallow periodically. Outside the fence was land used by nomads. The nomads, like the herdsmen in 1800s Oxford, increased their heads of cattle without planning for its impact on the greater good. The soil eroded, the plants died, then the cattle died, and, ultimately, some of the people died.

How does this affect those of us who do not need to graze our cattle? Well, like the cows, we all need food, water, and clean air to survive. With the increasing consumption of resources in the West, increasing world population, and the ever-larger megalopolises with tens of millions of people, the limit of Earth’s carrying capacity is called into question. Earth’s carrying capacity is in itself the global commons. As in the tragedy of the commons Hardin described for the pasturelands of England, each economic and state actor in the world has an interest in maximizing its own economic benefit from exploiting the environment with little compelling incentive to conserve it in the global interest. Whether for cattle or humans, when too many take with too little thought to the rest of the population, the result is usually tragedy.