So asks Minderbender. China makes just this argument, arguing that because it has four times the population of the United States, it should be able to emit four times the amount of greenhouse gases. Think of the atmosphere as a sponge that can absorb a limited amount of the world’s carbon. China wants the largest piece of the sponge because it has the largest number of people.
What is wrong with this argument? Initially, consider how this idea, if generalized as a principle of international law, would apply in other contexts. The sea contains various fish stocks. Currently, fish stocks that are located near a country’s coasts are “owned” entirely by that country. The rest of the world has no rights to it. Other fisheries are in the high seas. These stocks are for the most part not regulated: any country can authorize citizens to take them. Also consider mineral deposits in the sea bed under the high seas: these mineral deposits have traditionally been available to any country, though recent efforts have been made to regulate them under the Law of the Sea convention (to which the United States is not yet a party).
If China should have a per capita share of the atmosphere, then presumably it should have a per capita share of the fish stocks and mineral deposits beneath the high seas. We could go farther and ask, Why should any country have exclusive rights to resources in its territorial seas or, for that matter, on its own territory? Oil is oil: it is the same substance whether it exists under the oceans or under land. If China has a per-capita claim to oil under the ocean, why not to oil under the sands of sparsely populated Saudi Arabia? Or, to put this differently, why should China get carbon rights on a per capita basis if it is not willing to share (say) land rights on a per capita basis with (say) the Vietnamese?
The logic leads to a picture of the world as a basket of resources that should be distributed to countries on a per capita basis. Where the countries are actually located—how close they are to particular resources—is morally irrelevant. Landlocked Lesotho should have a share of fisheries, whaleries, mineral deposits in Norway, and the atmospheric carbon sponge. What matters is individuals, not countries, and individuals should have access to global resources on a per-capita basis. Who could object to this?
There are a few problems.
First, the per-capita principle would give governments incentives to expand (or not limit) their population. The bigger the population, the more of the world’s resources the government may claim. It would be better if governments were given incentives to limit their populations rather than expand them.
Second, do we really want the world’s resources divided up so that the biggest countries get the most? Is it relevant that some of the biggest countries have corrupt (Bangladesh), authoritarian (China, Russia), or otherwise less-than-efficient governments (India, Indonesia, Nigeria, Pakistan, Philippines), and therefore are unlikely to get most or even much or even any of the wealth to their people?
Third, the per-capita principle, whatever its attractiveness in the abstract, is in tension with the way that the world is organized and governments actually operate. Governments consider themselves responsible to their populations (or subsets thereof), and not to people living in other countries. Governments sometimes extend aid and resources to people in other countries who are suffering from a natural disaster or entrenched poverty, but never to people in other countries simply by virtue of their number. This leads to the final point.
Fourth, there is nothing ethically attractive about the per-capita principle. To see why, compare the United States (which has a population of 300 million) and Malawi (which has a population of 13 million). The United States has a per capita GDP of $40,000; Malawi’s is about $600. According to the per-capita principle, the United States (and, of course, China) should have greater carbon rights than Malawi, yet the United States (and China) are much richer than Malawi. If we are allocating the costs of greenhouse-gas abatement on an ethical basis, why give preference to states that happen to be big rather than states that are poor?