On her visit to India two days ago, Secretary of State Hillary Clinton was publicly rebuffed when she raised the problem of global climate change.    The Indian environment minister declared “we are simply not in the position to take legally binding emissions targets.”

No single country can address this problem on its own.  Hence the international negotiations that will take place in Copenhagen in December to try to find a successor treaty to the Kyoto Protocol.   But the international effort has run into a seemingly insurmountable roadblock.     On the one hand, the US Congress is clear: it will not impose quantitative limits on US emissions of greenhouse gases if China, India, and other developing countries don’t impose quantitative limits on theirs.   Indeed, that is why the Senate was unwilling to ratify the Kyoto Protocol ten years ago. The logic seems completely reasonable:  why should US firms bear the economic cost of cutting emissions if carbon-intensive activities would just migrate to countries without caps and global emissions continue their rapid rise?   On the other hand, the leaders of India and China are just as clear:   they are unalterably opposed to cutting emissions until after the United States and other rich countries go first.   And why should they?   The industrialized countries created the problem of global warming, in the process of getting rich;  the poor countries should not be denied their turn at economic development.  As the Indians point out, Americans emit more than ten times as much carbon dioxide per person.      

A total impasse.  Or is it?   I see one — and only one – practical solution to this apparent Catch-22:   The United States agrees to binding emission cuts — something like those in the Waxman-Markey bill that passed the House of Representatives on June 26;  and, simultaneously, China, India, and other developing countries agree to a path that immediately imposes on them binding emission targets — but targets that in their early years simply follow the so-called Business-as-Usual (BAU) path.    BAU is defined as the rate of increase in emissions that these countries would have experienced anyway, in the absence of an international agreement, as determined by experts’ projections.

The idea of developing countries committing only to BAU targets would provoke outrage from both environmentalists and US business interests, because it does not obligate these countries to cut emissions.  But both of those groups should realize that this commitment would be far more important than it sounds. It would preclude the carbon leakage which, absent such an agreement, would undermine the environmental goal.  It would mitigate the competitiveness concerns of carbon-intensive industries in the rich countries.  

This approach recognizes the reality that it would be irrational for China and India to agree to substantial cuts in the short term.   Indeed these countries, for their parts, will probably react with outrage at being asked to take on binding targets of any kind at the same time as the United States.   But they should also come to realize that they would actually gain in strictly economic terms from such an agreement, by acquiring the ability to sell emission permits at the world market price.

Of course an environmental solution also requires that China and the others subsequently make cuts below the Business as Usual path in future years, and eventually make cuts in absolute terms.   This can be done in such a way that the developing countries are not asked to make cuts that are different in nature than those made by Europe, the United States, and others who have gone before them, taking due account of differences in income.  But no country – rich or poor – will make sacrifices in any given period that impose huge economic costs on it.   It is time to stop making sweeping proposals that assume otherwise, and to pursue instead the narrow thread of the politically possible.

The effects of a changing global climate show up gradually, decade by decade. The effects of a changing US political climate have also been showing up gradually, year by year. A watershed was reached June 25, when the US Congress for the first time approved a bill to limit emissions of Greenhouse Gases (GHGs), by a vote of 219 to 212. But the Senate hurdle will be tougher.  The attempt to address Climate Change still has a very long way to go.

The problem

Climate Change is of course a global externality. Due to the free-rider problem, no single country, especially the United States, is likely to act on its own. The best solution is a multilateral treaty in which all countries commit to serious action together. In December of this year, a Conference of Parties to the UN Framework Convention on Climate Change will meet in Copenhagen, in the hope of negotiating a successor treaty to the Kyoto Protocol.

Three critical attributes were missing from the Kyoto Protocol. These attributes need to be included in any realistic attempt to tackle the reduction of year-2100 GHG concentrations to levels considered less dangerous by scientists:

i) Comprehensive participation – that is, acceptance of quantitative limits on emissions – by all major countries, including the US and developing countries.

ii) A credible framework that can establish a path for emissions reductions extending throughout the century, not just five years ahead.

iii) Some reason to think that all countries will be willing to join and then comply. This precludes targets that impose enormous economic costs on any major countries in any decades relative to the alternative of dropping out of the treaty.

For ten years — since I worked on Kyoto in the Clinton Administration — I have been thinking about how to design such a framework for assigning quantitative limits across countries. I now have a complete proposal to offer. It builds on the foundations of Kyoto, in that it accepts the framework of national targets for emissions and internationally tradable permits. But it attempts to solve the most serious deficiencies of that agreement: incomplete country participation, the need for long-term targets, and the economic incentive for countries to fail to abide by their commitments.

Although there are many ideas to succeed the Kyoto Protocol, the existing proposals are typically based on just one or two out of the following three philosophical approaches:

· science (e.g., capping global concentrations at 450 ppm) or

· equity (e.g., equal emissions per capita across countries) or

· economics (weighing the economic costs of aggressive short-term cuts against the long-term environmental benefits).

My emissions reductions plan is a bid to offer a more practical alternative: in addition to those three considerations, it is based heavily on politics.

More specifically, any future climate agreement must in practice comply with six important political constraints.

1) The US will not commit to quantitative targets if China and other major developing countries do not commit to quantitative targets at the same time, due to concerns about economic competitiveness and carbon leakage.

2) China and other developing countries will not make sacrifices different in character from those made by richer countries that have gone before them.

3) In the long run, no country can be rewarded for having “ramped up” its emissions high above the levels of 1990.

4) No country will agree to participate if the present discounted value of its future expected costs is more than, say, 1% of GDP.

5) No country will continue to abide by targets that cost it more than, say, 5% of GDP in any one budget period.

6) If one major country drops out, others will become discouraged and the system may unravel.

The proposal

The proposed plan sets the emissions caps using formulas that assign quantitative emissions limits to countries in every five-year period from now until 2100. Operationally, four political constraints are particularly important in specifying the formulas.

· First, “carbon leakage” is precluded, by including all countries from the beginning

· Yet developing countries are not asked to bear any cost in the early years.

· Even later, developing countries are not asked to make any sacrifice that is different from the earlier sacrifices of industrialized countries, accounting for differences in incomes.

· Finally, no country is asked to accept targets that cost it more than 1% of GDP cumulatively, nor more than 5% of GDP in any given budget period.

Under the formulas, rich nations begin immediately to make emissions cuts in line with what their leaders have already committed to.  Developing countries agree to maintain their business-as-usual emissions in the first decades, but over the longer term agree to binding targets that ultimately reduce emissions well below business as usual. This structure precludes energy-intensive industries from moving operations to developing countries (i.e., leakage) and gives industries a more level playing field. However, it still preserves developing countries’ ability to grow their economies; they can even raise revenue by selling emission permits. In later decades, the emissions targets asked of developing countries become stricter, following a numerical formula. However, these emissions cuts are no greater than the cuts made by rich nations earlier in the century, accounting for differences in per-capita income, per-capita emissions, and baseline economic growth.

More specifically, the formula incorporates three elements: a Progressive Reductions Factor, a Latecomer Catch-up Factor, and a Gradual Equalization Factor.

· The Progressive Reductions Factor requires richer countries to make more severe cuts (relative to their business-as-usual emissions) than poor countries.

· The Latecomer Catch-up Factor requires nations that did not agree to binding targets under Kyoto to make gradual emissions cuts to account for their additional emissions since 1990. This factor prevents latecomers from being rewarded with higher targets, or from being given incentives to ramp up their emissions before signing the agreement.

· Finally, the Gradual Equalization Factor addresses the fact that rich countries are responsible for most of the carbon dioxide currently in the atmosphere. During each decade of the second half of the century, this factor moves per capita emissions in each country a small step in the direction of the global average of per capita emissions.

The formulas, for some convenient parameter values, turn out to imply that global emissions peak around 2035.  (See graphs below.) This targets result in a world price of carbon dioxide that reaches an estimated $20-$30 per ton in 2020, $100-$160 per ton in 2050, and $700-$800 per ton in 2100, according to economic simulations using the WITCH climate model courtesy of Valentina Bosetti. Most countries sustain economic losses that are under 1% of GDP in the first half of the century, but then rise toward the end of the century. The simulations also show that atmospheric concentrations of CO2 stabilize below 500 ppm in the last quarter of the century, and world temperatures increase by about 3 degrees. Each of the six political constraints listed above is satisfied.

Conclusion

The framework here allocates emission targets across countries in such a way that every country is given reason to feel that it is only doing its fair share, comparable to what  others have done before it. Furthermore, the framework – a decade-by-decade sequence of emission targets determined by a few principles and formulas – is flexible enough that it can accommodate major changes in circumstances during the course of the century. The hope is that only such a combination of continuity and flexibility can make the process dynamically consistent, i.e., credible.

Most climate scientists say that 500 ppm is not a sufficiently aggressive goal. We (my collaborator, Bosetti, and I) have not yet been able to achieve year-2100 concentrations of 450 ppm while obeying the same political-economic constraints. But we are still working on it. Stay tuned.

The detailed proposal is “An Elaborated Proposal for Global Climate Policy Architecture: Specific Formulas and Emission Targets for All Countries in All Decades,” NBER WP, April 2009. Forthcoming, 2009, in a volume edited by Joe Aldy & Rob Stavins for  the Harvard Project on International Climate Agreements, Cambridge University Press. Editors’ summary of the volume is at Post-Kyoto International Climate Policy, Cambridge University Press.   (See also Stavins’ blog, especially, for analysis of the Waxman-Markey bill.)

[Readers wishing to post comments are referred to the version of this post on the RGE site.]

Most international summit meetings are long on photo-opportunities and short on substance.   There was a great danger that last Thursday’s G-20 meeting in London would be merit comparison to the failed World Economic Conference of 1933, which was also held in London.   This one, however, did have genuine substance.   

Nobody reads the communiques, or listens to the press conferences of leaders or finance ministers. But here is the substance:

Top of the list of accomplishments was expansion of IMF resources. The new SDR allocation was perhaps the most noteworthy and unexpected decision: those observers who have proposed such a step in the current international crisis, or in past international crises, have usually been dismissed as pipe-dreamers (John Williamson, Dani Rodrik, George Soros, Joe Stiglitz…). In addition, there seems to have been some forward movement on international regulation of the financial sector, as the Europeans wanted. Although President Obama acquitted himself well overall, the failure to achieve agreement for coordinated additional fiscal stimulus, as the Americans wanted, was probably the greatest shortcoming of the meeting.

I believe the G-20 meeting will be remembered historically, but not primarily for the above reasons. It will be remembered as the occasion on which primary emphasis shifted from the G-7, the global steering group that until now has had a monopoly on real economic decision-making power, to the G-20. Of the various substantive ways in which developing countries could and should have been given more representation in recent years, the shift to the G-20 is the first one to have actually taken place.