What Makes Greenhouse Sense?

Thomas C. Schelling

From Foreign Affairs, May/June 2002

Summary:  The Kyoto Protocol need not be a partisan issue. Climate change needs to be addressed, but the 1997 pact was never going to pass the Senate. By abandoning it, Bush at least avoided hypocrisy. It might take a century to reach a consensus on solving the greenhouse gas problem, but that is no excuse for wasting time getting started.

Thomas C. Schelling is Distinguished University Professor of Economics and Public Affairs at the University of Maryland.

The Kyoto Protocol should not be a partisan issue. The percentage reduction of greenhouse-gas emissions to which the United States committed itself by signing the 1997 Protocol to the 1992 un Framework Convention on Climate Change was probably unachievable when the protocol was adopted. The protocol then languished in Washington for the final three years of the Clinton administration, which chose not to present it to the Senate for ratification. In accordance with a Senate resolution calling for the full participation of the main developing countries in the protocol's emissions-cutting requirements, that pause was supposed to allow time for negotiation to bring those countries on board. But nobody thought any such negotiation could produce results, and no negotiation was ever attempted. George W. Bush, succeeding to the presidency three years after the protocol's signing, had some choices and may not have made the best choice when he rejected the plan outright last year. But the one option he did not have was to submit the protocol to the Senate for ratification.

The U.S. "commitment" to the protocol meant cutting emissions significantly below their 1990 level by 2010 -- which required a 25 or 30 percent reduction in projected emissions levels. Such a cut was almost certainly infeasible when the Clinton administration signed the protocol in 1997. Three years later, with no action toward reducing emissions, no evidence of any planning on how to reduce emissions, and no attempt to inform the public or Congress about what might be required to meet that commitment, what might barely have been possible to achieve over 15 years -- 1997 to 2012 -- had become unreasonable. The Senate will not confirm a treaty unless it knows what actions the "commitment" entails, and no president could answer that question without a year's preparation. No such preparation appears to have been done in the Clinton administration. Bush, in stating that he would not submit the treaty to the Senate, at least avoided hypocrisy.

In declining to support the Kyoto Protocol, Bush outlined three concerns regarding any future greenhouse-gas agreement. First, the main developing countries need to adhere as full participants, as the Senate had earlier resolved; so far, developing countries have made clear they have no intention of doing so. Second, he cited the immense uncertainty about the likely extent of climate change and its impact on society. Third, he expressed a preference for "voluntarism" over enforceable regulation, even though he did not make clear whether his "voluntarism" referred to domestic or international commitments.

A FAIR DEAL?

There is no likelihood that China, India, Indonesia, Brazil, or Nigeria will fully participate in any greenhouse-gas regime for the next few decades. They have done their best to make that point clear, and it serves no purpose to disbelieve them. Although their spokespersons regularly allege that rich countries are the most worried about climate change, developing nations have the most to lose from climate change. They are much more dependent on agriculture and will therefore suffer much more from global warming. Constrained by poverty and technological backwardness, their ability to adapt to climate change is limited. The best way for developing countries to mitigate global warming, therefore, is through economic growth.

There are undoubtedly opportunities in those countries for improved energy efficiencies that may simultaneously cut carbon dioxide emissions and improve public health; China, for example, could easily reduce its dependence on coal. But any major reductions in worldwide carbon dioxide emissions over the next few decades will have to be at the expense of the rich countries. Calling for the immediate participation of the big developing nations is futile. Once the developed countries have demonstrated that they can cooperate in reducing greenhouse gases, they can undertake arrangements to include developing countries in a greenhouse-gas regime, aiding them with economic incentives.

THE UNCERTAINTY PRINCIPLE

As Bush has emphasized, there are many uncertainties in the greenhouse-gas debate. But what is least uncertain is that climate change is real and likely to be serious. In any case, residual ambiguity about this question should not delay essential research and development in nonfossil energy sources, energy conservation, and policies to exploit the most cost-effective ways to reduce emissions.

A huge uncertainty that will make any lasting regime impossible for many decades to come, however, is how much carbon dioxide can safely be emitted over the coming century. A reading of the evidence -- including climate sensitivity, regional climate changes, likely severity of impact, and the effectiveness of adaptation -- suggests that the highest ceiling for carbon dioxide concentration, beyond which damage would be unacceptable, is probably between 600 and 1,200 parts per million. (It is currently about 370 ppm.) Further uncertainty exists about how much carbon dioxide can be absorbed into various natural sinks -- oceans and forests -- or sequestered underground or deep in the ocean. Thus any estimate of the level at which total carbon dioxide emissions worldwide over the coming hundred years should be capped is wide-ranging, falling between 500 billion tons and 2 trillion tons. (Worldwide emissions are currently approaching 7 billion tons, half of which stays in the atmosphere.) In any event, what is ultimately unacceptable depends on the costs of moderating emissions, and these costs are also uncertain.

As a result, any "rationing scheme" would necessarily be subject to repeated revision and renegotiation. It is noteworthy that the Intergovernmental Panel on Climate Change -- the international body, comprising more than a thousand scientists from scores of countries, that is the acknowledged (if controversial) authority on the subject -- has never proposed what concentration of greenhouse gases would constitute unacceptable damage. Nor has any other representative body yet dared to hazard an estimate.