Global warming is just that: a global — not national — issue

"Every country will make its own decisions, reflecting its own needs and interests," Condoleezza Rice announced at the start of a U.S.-sponsored conference on global warming in 2007. But, this seemingly reasonable sentiment by the secretary of state is precisely the wrong way to go.

To understand why, consider an old conundrum, eloquently described by ecologist Garrett Hardin some 40 years ago. He termed it "The Tragedy of the Commons"; sadly, this particular tragedy is still playing today.

Hardin asked us to consider the situation faced by many English herdsmen centuries ago. Some grazing land was privately owned, while the "commons" was shared property of the community at large.

Various citizens owned livestock, which they could graze on their own private lands or on the public commons. The commons became an early test of the common good.

Even before the advent of ecological science, it was well-known that overgrazing was harmful to grassland productivity, so shepherds sought to minimize the impact on their own property. However, they also recognized that a healthy commons benefited everyone. Still further, they each reasoned that if they refrained from grazing their animals on the commons, others doubtless would take advantage of this restraint and fatten their flocks on the public lands.

As a consequence, tendencies to be prudent were suppressed because individuals figured that if the commons was going to be degraded, anyhow, they might as well be in on the profit. The result was deterioration of the commons, until it was no longer fit to support sheep, or shepherds.

The tragedy of the commons, then, is that individuals — seeking to gain personal benefit — find themselves engaging in behavior that hurts everyone.

This tendency can also be generalized to other situations, where short-term selfish payoff conflicts with long-term public good.

For example, there may be short-term, self-centered benefit for a factory owner to use the atmosphere as a public sewer; after all, even if his effluents pollute the air, the cost is borne diffusely and more or less equally by everyone who breathes, whereas the owner personally is saved the expense of having to install pollution-control devices.

Similarly with overuse of scarce resources: It may be inconvenient to recycle and, in fact, easier for individuals simply to throw their garbage away, or to use more than their share of scarce commodities. In the process, they derive personal gain or enhanced convenience, while the cost — in overcrowded dumpsites or worldwide resource shortages — is, by contrast, a general one. Besides, if they don't abuse the environment, then surely someone else will — which is just what the flock owners told themselves about the commons.

The tragedy of the commons has global dimensions: Scandinavian forests and lakes suffer from acid rain because of the effluents of English smokestacks, while Britain gets the economic benefit. Japan and Norway periodically defy international outcry while hunting the world's great whales to the verge of extinction. Brazil seeks to benefit economically from the Amazon rain forest, even though such "benefit" seems destined to destroy it, to the ultimate detriment of everyone.

As for global warming, the lesson should be obvious: The Earth's atmosphere and climate are an essential "commons," threatened precisely by the tragic mindset expressed by Rice and the Bush administration, in which every country is encouraged to "make its own decisions, reflecting its own needs and interests."

Fortunately, the matter of climate change need not end tragically; solutions exist, but just as shepherds needed to make decisions that were group-oriented rather than focused on narrow, individual interests, global- warming demands share mandatory restraint, reflecting "needs and interests" that aren't national, but global.

David P. Barash is a professor of psychology at the University of Washington. His most recent book is "Natural Selections: Selfish Altruists, Honest Liars and Other Realities of Evolution."