A new framework for reducing carbon emissions takes a crack at the knottiest dilemma confronting a global climate solution: how to divvy cuts between rich and poor nations.
A new study published Monday attempts to sidestep the rancor, finding that virtually every country has a class of individuals—the so-called "high emitters"—enjoying a rich, carbon-intensive lifestyle. If those individuals, no matter their locale, are forced to take responsibility for their emissions, a great swath of countries become participants in the climate effort, the study claims.
"Rich people in poor countries shouldn't be able to hide behind the poor people in those countries," said Robert Socolow, co-director of Princeton's Carbon Mitigation Initiative and a co-author of the study, published in the journal Proceedings of the National Academy of Sciences.
The problem has dominated talks leading to December's Copenhagen negotiations on a post-Kyoto accord. Developing nations expect the industrialized world to do the heavy lifting on emissions cuts; industrialized countries, noting that the developing world will account for upwards of 97 percent of future emissions growth, want assurances that such growth will be curbed.
The analysis, "Sharing global CO2 emissions reductions among one billion high emitters," by a group of Princeton University researchers, proposes spreading responsibility for reductions among individuals rather than countries.
Under this framework, the international community would draw a single, global line for carbon emissions. Countries would then be responsible for reducing the carbon footprint of individuals living above that line. Emissions from individuals living below the line do not factor into the accounting.
Overall, the researchers found that the United States and China would have the largest carbon dioxide reduction targets, while Russia, India, the Middle East, South Africa and north Africa would all have sizable targets, due to their energy industries.
The proposal also sets a floor for the 3 billion people predicted by 2030 to be emitting less than one ton of carbon dioxide a year. Those people—the poorest of the poor—should focus solely on bettering their lifestyles, and they should do so via any economical means, the authors say.
They can safely come up to one-ton-a-year emissions target without breaking the global carbon bank.
It is folly, in other words, to light 10 villages via solar power when the same money could equip 100 villages with diesel-powered generators, Socolow said.
"There's no reason people at that level have to meet carbon goals," he said. "It starts with the high emitters."
The plan is being hailed by many climate experts for this inherent fairness: Industrialized countries bear the brunt of the labor, as those nations have the most residents living above any carbon line. But many nations in the developing world would also have to take some action as their citizenry prospers and begins to enjoy a more carbon-intensive lifestyle.
"Developing countries want attention to fairness," Socolow added. "We can talk about fairness in a way that is defensible in the minds of the high per-capita [emitting] countries.
"It's mischievous, but it's meant to be a logjam-breaking concept."
Indeed, perhaps the most striking aspect of the study, said several climate experts familiar with it, is that by 2030 the world's one billion highest emitters will be spread evenly across four major economic regions of the globe: the United States; the industrialized world minus the U.S.; China; and the developing world minus China.
The whole world, in other words, must act.
"These numbers strengthen our conviction that industrialized countries will have to take the lead in reducing their emissions, but that the fight to prevent dangerous climate change can only be won if all countries act together," said Ottmar Edenhofer, a professor at the Technical University Berlin and co-chair of the Intergovernmental Panel on Climate Change Working Group III. He was not affiliated with the research.
Other experts praise the framework's potential to cut through 17 years of climate stalemate. One particular strength, several said, is its embrace of the entire spectrum of emitters - the abject poor, the broad middle, the high emitters.
"It's ingenious," said Larry Susskind, a professor of environmental planning at Massachusetts Institute of Technology who was not involved in the study. "It's a great way to shift the conversation."
The study assumes world leaders can agree to a global carbon emission reduction target. Once that's set, the big question is how to divide responsibility for meeting that target among different countries.
The new framework assigns that responsibility to individuals, not nations. The authors looked first at national income distributions based on World Bank data, then converted those distributions to carbon footprints based on emissions data from the Energy Information Agency.
The result is a series of projections showing the distribution of individual emissions for different regions. Each country worldwide would be assigned an emissions target based on the number of "high-emitter" individuals within their borders and their aggregate emissions. While all emissions contribute to global warming, the authors found that targeting the highest billion or so emitters gives the rest of the world room to continue to grow and develop.
"In principle," the authors wrote, "no country gets a pass, because even in the poorest countries some individuals have CO2 emissions above the universal emissions cap."
The idea was born, in part, from travels to India and other developing countries, Socolow said, where thriving cities support a middle and upper class enjoying a decidedly high-carbon lifestyle.
"Lack of attention to sustainable objectives in the developing world among people who live like us means they're going to replicate the same wastefulness," he said. "If those countries are given a free pass for the next decade or two, they're going to use that time to do the same foolish things we did."
Scientists have long held that to prevent the most dire effects predicted under a disrupted climate, society must slash emissions from today's levels and drastically alter growth projections.
At a minimum, scientists agree, the world needs a 30 percent cut by 2030 with respect to business-as-usual projections - a daunting challenge. But this is not the biggest problem confronting the world's governments on the climate change front.
That problem would be the vast disparity—generally linked to wealth—in per-capita emissions across the globe.
Americans, on average, pump 20 tons of climate-warming carbon dioxide into the atmosphere a year. Europeans average between 10 and 12 tons. Chinese are closer to four tons. And some three billion people worldwide emit less than one ton per year.
How to close that gap has been a major stumbling block in climate negotiations since 1992, when 172 countries—including the United States—agreed to divide responsibilities for emissions cuts based on economics.
The idea was simple: Rich nations would take the lead on cuts, with developing nations following at some unspecified later date.
But the rich have moved slowly, and now many governments are balking at undertaking expensive and disruptive action while the developing world gets a free pass.
"The rich should lead, but the rich can't get domestic legislation enacted until they can level the playing field," said Robyn Eckersley, a professor in the School of Social and Political Sciences at the University of Melbourne.
"Those domestic demands are totally undermining the environmental justice elements of the international climate regime."
The fairest goal is widely seen as a per-capita allocation, where everyone in the world is given the same cap on personal greenhouse gas emissions. Developing nations favor an approach, known as "contraction and convergence," that would bring rich countries' per capita emissions down while increasing the allowance for everyone else.
To hold climate change to a minimum and keep atmospheric carbon dioxide concentrations stable at 450 parts per million, that per capita line would need to be well below the current global per-capita average of four tons of carbon dioxide per year.
But it also means revolutionary—and for now, at least, politically impossible—lifestyle changes for the Western world, particularly the United States, where annual per capita carbon emissions top 20 tons.
Another approach, also favored by developing economies, seeks to quantify historical responsibility and capacity to pay. Those countries above the per-capita income threshold pay the costs of the global transition to new energy and emissions paradigms.
That's a non-starter for most rich nations, which seek a different type of equity. They're adding caveats to their cuts, proposing tariffs or other penalties on imports from countries that don't impose tough greenhouse-gas limits. Last month, for instance, the U.S. House of Representatives tacked a "border adjustment tax" to its landmark climate bill, prompting criticism from President Obama and much of the developing world.
That's where this new study could break the impasse.
By focusing on high emitters worldwide, say study authors, it offers a bridge to a more equitable per capita emissions cap.
"The two approaches will eventually converge," said Massimo Tavoni, a researcher at Princeton's Environmental Institute and a study co-author. "This gives you the transition to get to equal per capita emissions.... It's obviously very fair, but it's just very far in the future."
Of course, none of this really works unless the developed world takes the lead. The original 1992 United Nations climate convention, ratified by more than 160 countries, including the United States, says that the developed world needs to act first.
They haven't done that yet, and experts agree time is quickly running out. This proposal is a way to bring the world together soon, they say.
"The north has got some sort of come-to-Jesus moment in its future. We just don't know how it's going to play out," said Tom Athanasiou, founder of EcoEquity, a think tank focused on global climate justice. "It's a terrible situation. It just is. We're way late."
Whether this proposal will earn a spot at the negotiating table is anyone's guess, but Eckersley and Susskind are optimistic its simplicity and fairness could cut through the ossified and polarized negotiations.
"This is not a panacea. This is not all you do," Eckersley said. "There are a lot of other factors you have to put on the table. But this is a starting point."