By Cass R. Sunstein
Friday, August 18, 2006
Sensible people now agree that climate change creates major risks and that the world should be taking significant steps to reduce greenhouse gas emissions. But there is a neglected obstacle to achieving such reductions, and it is the biggest source of the stalemate in international negotiations.
The obstacle stems from the unusual incentives of the United States and China. As the world's leading contributors to climate change, these are the two countries that would have to bear the lion's share of the cost of greenhouse gas reductions. At the same time, they are both expected to suffer less than many other nations from climate change -- and thus are less motivated to do something about it. And while the international spotlight has rightly been on the behavior of the United States, China will soon present the more serious problem.
In recent years the United States has accounted for about 21 percent of the world's greenhouse gas emissions. China comes in second at about 15 percent. While many countries have stabilized their greenhouse gas levels, emissions from both nations, but especially China, are growing rapidly. Current projections suggest that by 2025 total emissions from the United States will increase by about one-third.
By that year, China's emissions are expected roughly to double, making China the planet's leading source of such gases. (Emissions from the United States will, of course, continue to be far higher on a per-capita basis.) Within 20 years China will account for nearly one-quarter of the world's greenhouse gas emissions. It follows that if an international agreement requires reductions, China and the United States will have to bear the brunt of the expense.
By contrast, the biggest losers from greenhouse gas pollution are likely to be India and Africa. Some of the most detailed, careful and influential projections have been made by Yale University's William Nordhaus and Joseph Boyer. Nordhaus and Boyer show that in terms of human health and agricultural loss, India and Africa are by far the most vulnerable regions on Earth. Because of an anticipated increase in malaria, Africa will probably be hit especially hard, and India is expected to suffer a large increase in premature deaths as well.
If climate change occurs at the rate expected by many scientists, it will have a much less serious effect on the United States, and even less than that on China. In the United States, agricultural production is expected to suffer relatively little. In China, agriculture is actually projected to benefit from a warmer climate.
Both nations are expected to suffer some losses in terms of human health, but compared with projections for other countries those losses will be disproportionately small. A key reason is that the United States and China are not expected to be highly vulnerable to increases in malaria and other climate-related diseases.
In terms of percentage reductions in gross domestic product, India and Africa together are expected to lose about 10 times more from climate change than the United States -- and about 20 times more than China.
We should now be able to see why China has refused to participate in any international agreement to control climate change. Chinese officials know that their nation will soon be the world's largest emitter of greenhouse gases, and they believe that because of their economy and their location, they have relatively little to gain from reducing those emissions.
We should also be able to see why most U.S. officials, whether Democratic or Republican, have been so reluctant to favor stringent limits on greenhouse gases. Such limits would be more costly for the United States than for most other nations, because the United States is and will continue to be the largest per-capita source of greenhouse gases. And on the current projections, Americans face comparatively lower risks from climate change.
Of course, any such projections involve a lot of guesswork, and reasonable people can differ. If global warming turns out to be either abrupt or greater than anticipated, it might well inflict catastrophic losses, leading to extremely serious problems for the United States and China alike. And even under current projections, the risks faced by the world's leading emitters can hardly be dismissed as trivial. National economies are interdependent, and if the world as a whole suffers from climate change, the United States and China will pay a large price.
But the troubling fact remains: The two nations now most responsible for the problem have comparatively little incentive to do anything about it. That is why, if the nations of the world really mean to take substantial steps to reduce greenhouse gases, they have two options.
First, they might find a way to convince the United States and China that they have a moral obligation to protect the planet's most vulnerable people. The United States has long benefited from technologies that, while promoting its economic growth, are imposing serious risks on disadvantaged people in India, Africa and elsewhere.
Second, the world's nations might try to convince these two countries that emissions reductions are less expensive, and more beneficial for their own citizens, than the recent projections suggest. Environmentally friendly innovations have often turned out to be far less costly than anticipated. (And if persuasive evidence is found that indicates greater losses for both nations from global warming, there will be a stronger incentive to try to innovate.)
It is only with such an incentive, or a sense of moral duty, that the United States and China are likely to participate in serious international efforts to reduce greenhouse gases. And without the participation of the two countries, no such efforts are likely to have a substantial effect on the problem.
The writer teaches at the University of Chicago and is the author of "Infotopia: How Many Minds Produce Knowledge."