Princeton University's team of scientists has developed a new way of dividing responsibility for carbon emissions among countries.
The method is outlined in a paper, titled "Sharing Global CO2 Emissions Among 1 Billion High Emitters," published online in the Proceedings of the National Academy of Sciences.
The authors include Stephen Pacala, the Frederick D. Petrie Professor of Ecology and Evolutionary Biology, and Robert Socolow, a professor of mechanical and aerospace engineering.
According to the authors of the research paper, the approach uses a new fairness principle based on the "common but differentiated responsibilities" of individuals, rather than nations.
"Our proposal moves beyond per capita considerations to identify the world's high-emitting individuals, who are present in all countries," the team said.
The proposal would use individual emissions as the best, fairest way of calculating a nation's responsibility to curb its output of carbon dioxide, according to the authors.
The methodology does not mean that individuals would be singled out, only that these calculations would form the basis of a more equitable formula.
In the new scheme, emission reduction targets for each country are calculated in a multi-step fashion.
The researchers used a strong correlation between income and emissions to estimate the emissions of individuals in every country.
Next, they combined these factors to see how individual emissions are distributed globally.
Looking forward to 2030, the researchers estimated first individual emissions and then a global emission total at that future time based on projections of income, population and energy use.
They imagined the world's leaders deciding now that the projected global emission total for 2030 is dangerously high, choosing a lower global target and seeking a process by which the work of achieving this new global target could be divided among the world's nations.
The proposal "provides a significant starting point for breaking through the current impasse over the respective mitigation responsibilities of developed and developing countries," said Robyn Eckersley, a professor in the School of Social and Political Sciences at the University of Melbourne in Australia.
The researchers believe their new framework is useful in that it establishes a uniform "cap" on emissions that individuals should not exceed.
By counting the emissions of all the individuals who are projected to exceed that level, the world leaders could provide target emissions reductions for every country.