George Bush routinely gets beaten up by environmentalists because they think he should be leading the charge to do something about the greenhouse effect. In fact, among the economists who study the problem, the opposition to quick action runs fairly deep -- aside from uncertainty over the climatological models.

Typical is Thomas C. Schelling, a thinker who is senior enough to be serving as president of the American Economic Association and who is leaving Harvard for the University of Maryland this week after a 30-year span. A look at the 69-year-old Schelling's career illuminates a good bit of the origins of present-day thinking about the greenhouse effect.

In the 1960s, no academic figure exemplified the romance of Harvard in Washington better than Schelling. It was said that Robert McNamara was influenced by his thinking, more than by any other. The son of a naval officer and veteran of a long Marshall Plan stint after World War II, Schelling wrote a book on algebraic economics in his spare time during the late 1940s and turned it in for a Harvard Ph.D. Then, after a stint at the Rand Corp., he took up thinking about nuclear war, earning a reputation as a tough-minded peacenik in the strenuous top-secret campaign against the Air Force plan to establish a testing treaty.

Schelling published ''The Strategy of Conflict'' in 1959 (sample chapter: ''Bargaining, communication and limited war'') But it was in John Kennedy's Camelot that Schelling really burst upon the Washington scene, commuting for his day-a-week consulting job on Friday. During Lyndon Johnson's years the economist-cum-strategist was everywhere, advising the best and the brightest in the Defense Department and the National Security Council.

But in the wake of the U.S. decision to spread the Vietnam War to Cambodia in April 1970, Schelling led a delegation of 12 Harvard professors to Washington to call on old friend Henry Kissinger, who was then national security adviser.

''We took turns speaking,'' Schelling recalls. ''We told him that we had thought of the executive branch as our friend, of Congress as our enemy. From now on we would reverse it. Henry went gray in the face, he slumped in his chair. I thought at the time that he suffered serious depression. But there was no sign that it ever had any effect.'' For Schelling, the vow to perform no more work for the executive branch was an especially momentous pledge. It cost him both his audience and his information.

After a laborious intellectual retooling, there followed a trickle, then an outpouring of work on human behavior, energy and climate. There was still the garment bag on the shoulder at the airport on Thursday evenings, but now Schelling's clients included Congress, the National Academy of Science and various foundations. The issues were fossil fuels, racial discrimination, sexual politics, drug addiction, the cigarette habit, medical ethics, climate change, even wearing mittens in your sleep to keep from scratching poison ivy. (''Treating your sometime self as though it were somebody else is a ubiquitous and familiar technique of self-management.'')

At the heart of it all was game theory. Today, of course, the systematic taking account of other people's actions in your theorizing is all the rage in economics. In fact, probably nothing is being talked about more frequently among teachers of economics than David Kreps's new graduate microeconomics textbook, which incorporates game theory for the first time in the deep-down architecture of the field. But when Schelling began writing about strategy in the 1950s, it was news to most economists -- so much so that his ''theory of interdependent decision'' was all but ignored by them.

In Schelling's hands, the most mundane choices are illuminated for their strategic considerations. Christmas savings clubs are seen as a way of binding oneself to save even in the face of temptation. Protective hockey helmets become an intricate exercise in collective choice, for nobody wears them voluntarily, while everybody benefits if they are mandated. It turns out to be easy to decide where to meet in New York City without making plans if you just think for a while about what places the other guy knows. (In another era, it would have been the Biltmore clock, of course.)

As Richard Zeckhauser says, ''Those who read Schelling and participate in his games learn a general principle: In any interactive situation, it is vitally important to look at matters from the side of the other party... . The other-people's-shoes approach is often recommended by softhearted promoters of compromise. The core principle, however, is that by understanding the other party's perspective, you will improve your comprehension of the situation dramatically and will come out better yourself. This is an important lesson for hard hearts as well.''

So what does Schelling's game-theoretic perspective suggest about the global warming debate? The prospects are not good, says Schelling, if you aim to prevent it from happening. Any nation that attempts to mitigate changes in climate through unilateral action pays the cost alone, he says, while sharing the benefits with the rest of the world -- and the benefits might not be all that great. If the United States decided to cut its fossil fuel use by a third over a 20-year span, for example, at a yearly cost of something like $150 billion to $200 billion, the result would be a mere 10 percent decline in the world's carbon dioxide emissions -- and that only if other countries did not increase their emissions. Much more significant effect could be accomplished if China, the Soviet Union and the United States agreed to give up the use of coal, but Schelling thinks the chances of a global fuel compact are remote today.

But then he brightens. ''What difference does climate change make, especially if it comes slowly? The interesting thing is that, to a first approximation, it isn't going to make any difference, at least to advanced countries, where there's hardly any economic activity that's terribly affected by the weather. Of course agriculture is, but agriculture is only 3 percent of GNP {gross national product}. So if agriculture costs went up even by a third, a 1 percent reduction of real GNP -- taking place over the course of a century, a period in which personal income would probably double anyhow -- would scarcely be noticed. Then if you look at what it's going to do to human health and human comfort and recreation, even extinction of species, it's very hard to identify. ...

''Now this may not be true for developing countries, where they are much, much more dependent on food production and where they may have much less margin for adaptability. This leads me to conclude that the countries that can afford to do something about it -- maybe Western Europe, the United States, Japan and a few others -- probably won't be able to identify a powerful national interest, not when it's time to talk about our president putting a dollar-a-gallon tax on diesel fuel and gasoline. And the countries where probably the most might need to be done, like India and China, the countries that are already very inefficient consumers of fuel, are probably going to become bigger and bigger consumers of it. They probably won't and shouldn't do anything to curb greenhouse emissions, unless somebody else pays for it. I think eventually it will get around to that -- but it will take 20 years instead of two years.''

David Warsh is a columnist for the Boston Globe.