The Population Bubble

By David Bacon

In the Roadrunner and Coyote cartoons there is usually a scene where Coyote, chasing Roadrunner, runs off a cliff. He continues on a horizontal line for a couple of seconds, looking increasingly puzzled and concerned, until he realizes his predicament, tries vainly to reverse course, and falls to the desert below.

This is symbolic of the situation ecologists call “overshoot.” Overshoot is when a species reproduces to a number that its environment can’t sustain.

In 1944, for example, 29 reindeer were introduced onto Saint Matthew Island in the Bering Sea. With few competitors, no predators and plenty to eat, the herd increased to about 6,000 by the summer of 1963, consuming almost all available food. That winter most of them died. The surviving population in 1966 numbered 42.

And now the species with the unique ability to change the environment on a colossal scale appears on the verge of making for itself a St. Matthew Island worldwide. At the end of the 19th century the human population was 1.6 billion. It is now 6.6 billion (in 2007). 
 
The food that made this amazing increase possible – there’s also sanitation and modern medicine, but food is the base – came primarily by boosting crop yields with petroleum. With fertilizer from natural gas, with crops bred to capitalize on that fertilizer and with petroleum – powered machinery and irrigation wells, we can produce huge yields – more than 7,000 pounds of corn per acre, for example.

Just one lifetime ago, corn yields were one-fifth of that. Wheat yields have almost tripled. Similar comparisons can be made for other grains. But, this can’t last. The aquifers, oil, and natural gas that made possible a fourfold population increase are finite.

Over the coming decades, petroleum will become harder and harder to find, extract, and put to use, until eventually it becomes unavailable for agriculture in any significant amount. Meanwhile, another 2 billion people are predicted worldwide by 2050. Increasing attention to the so-called peak oil problem focuses on its impact on airlines, car makers and the stock market. These will suffer, but not on the level of malnutrition and starvation for many, and a continuous struggle over decreasing resources for all.

Is the situation really this dire?  Agriculture accounts for a fraction of petroleum use in industrialized countries. We might reduce use elsewhere – more efficient cars, less plastic – and use the savings to keep crop yields high enough to feed everyone. But to make that work, short-term and local self-interest must yield to a long-term, global consciousness – a tall order.

Increased efficiency and alternative fuels might for a time fill the gap left by petroleum’s decline. But we have yet to devise an alternative as versatile as petroleum that can fill its huge role – especially in the face of relentlessly growing demand for energy. And whatever we do to support population growth will only make overshoot worse in the end.

In addition to unique abilities, we have a serious shortcoming. We are unwilling, perhaps unable, to see ourselves as subject to the same constraints as Earth’s other inhabitants. But in our dependence on the environment for food and water, we most certainly are subject to those constraints.

Without a solution, we will die just as surely as the St. Matthew reindeer. Given Earth’s limits, there already are too many of us for the long run. It is notoriously difficult for political leaders to seek moderate sacrifice today to prevent terrible sacrifice tomorrow when there is too little general recognition of the trouble ahead.

Can we be wilier than Wile E. Coyote? It’s hard to be optimistic. There is probably no real solution to this problem, only halfway measures to lessen the eventual impact. But every little bit will help.

David Bacon is a physician and retired Army colonel living in Aspen, Colorado. He wrote this for the Land Institute’s Prairie Writers Circle, Salina, Kansas. Published on January 18, 2007, and reprinted in the Fall 2007 Population Press. Reprinted with permission.