There are mounting fears that the upcoming conference of the parties of the United Nation Framework Convention on Climate Change will fall short of achieving a comprehensive global climate agreement. Many years have been lost since Rio and Kyoto, making every target harder to achieve, and there has been a shift toward more stringent and ambitious climate stabilization objectives, such as the 2 Celsius goal. A combination of less time and tougher goals means that significant mitigation action is now required in both the developed and the developing world. Actual national mitigation actions are at present extremely uncertain, and there is a real risk that current, strong disagreements about relative responsibilities will derail the entire process.
A major factor in the reluctance of countries to make commitments to a low-carbon economy is fear that change will be costly and that others will hold back: the free rider problem. Such fear is often accompanied by limited awareness of the distribution of global emissions today and expected in the future. To provide new insight into where and from whom emissions are generated, we have written a paper1, together with three coauthors. It moves the focus of attention from national per capita values of CO2 emissions to the emissions of the world’s individuals. Here we summarize some of the findings of paper and also add further analysis.
A Matter of Lifestyles and Energy Intensity
As of today, the discussion over allocating obligations across the countries of the world has mostly involved comparing nations on a per capita basis. We show that this is seriously incomplete. Individual CO2 emissions are very unequally distributed not only across countries but also within countries. This is a consequence of the strong relation that exists today between emissions and income, and of the large disparities in lifestyles and energy intensities across the world.
The key to our analysis is the development of credible, approximate estimates of the individuals emissions in each country that sum to the country’s total emissions. Using income distribution data from the World Bank and the U.N., we have developed a methodology for estimating individual carbon emissions for the year 2003 for 153 countries, covering almost all global emissions. The methodology accounts for the relation between expenditures and emissions2 and for the differences in national carbon intensities. From these national distributions we construct a global emission distribution. We also build a corresponding carbon emissions distribution for 2030, using U.S. Energy Information Agency’s International Energy Outlook (2009) “Business as Usual” scenario. We also use this scenario to project national and regional carbon emissions with the assumption that carbon emission inequality is unchanged at the national level. The analysis is restricted to fossil carbon emissions, which are arguably much more closely tied to income than biological emissions (notably, deforestation) or emissions of other greenhouse gases (notably, methane).
Three Emitters Classes
The emissions of the global middle class are approximately between today’s average for Brazil and the EU. The “low emitters” in the lowest bin represent more than half of the world’s 6.2 Billion people in 2003, but contributed only 11% of carbon emissions3.
At the opposite end, half of 2003 global emissions were created by 11% of the globalpopulation in the upper bin, the “high emitters.” Only the “global middle class” had emissions in proportion to their population, each roughly one-third of the global total.
Figure 1 also shows the three bin distributions for 2030, using regional CO2 emissions projections from the EIA’s International Energy Outlook “Business As Usual” scenario. The EIA projects an increase in global emissions of almost 70% between 2003 and 2030, while population increases by about 30%. Figure 1 shows that the greatest increase in population will happen in the global middle class, but that two-thirds of the incremental emissions will actually come from individuals whose annual emissions exceed 10 tCO2.
Geography of “High Emitters”. Where do they live?
It is natural to wonder where the “high emitters” live and will live. Figure 2 shows their global distribution by binning the world into four regions: the U.S., the rest of the OECD, China, and the rest of the world. The Figure shows that the “high emitters” in the OECD and non-OECD countries contribute approximately equal to global emissions in 2030, whereas in 2003 emissions of the “high emitters” in the OECD were 70% of total “high emitter” emissions. In this view of the world, where China’s rapid economic growth relative to most other countries is an assumption, China’s share grows from 4% to 30%.
|Figure 2 – Regional population shares in 2003 and 2030 for the high emitters (>10tCO2), click the picture to enlarge|
Taking as our point of departure the increasing dominance of “high emitters” (Figure 1), we propose that the responsibilities of countries or regions be assigned in proportion to the contribution of the emissions of its “high emitters” to the total emissions of “high emitters” (the fractions shown in Figure 2). The lower bound defining a “high emitter” changes with the global target: a tougher target results in a lower cut-off and more individuals in the top category. For example, if the global goal were to cap global emissions at today’s levels in 2030, the individual cap would be at about 10tCO2 (the threshold of the “high emitters”) and roughly one Billion people would exceed that cap. As seen in Figure 2, this group of individuals is roughly equally distributed in the US, other OECD, China and other non OECD countries, each with one quarter of a billion “high emitters.”
The allocation problem takes on important new dimensions when the focus shifts in this way from “high emitting” nations to “high emitting” individuals. In short, , “common but differentiated responsibilities” becomes a statement about individuals, not nations. Our fairness principle is that individuals with the same emissions have the same obligations, wherever they happen to live.
From “High Emitting” nations to “High Emitting” Individuals
Our proposal presumes that a process will be established that allows national allocation fractions to be reconsidered periodically as global development proceeds, national circumstances change, and more is learned about global climate change. From this perspective, Copenhagen is the first of many steps in the transition to a low carbon world.
In summary, our paper shows that a focus on individual emissions provides an important tool for dealing with the decarbonization transition. Fresh and even surprising insights into global emissions result when analysis moves beyond per capita data and all of the world’s high emitters everywhere are revealed. Hopefully, from these new insights, new solutions can be built4.
- New strategies to calculate emissions and to overcome the impasse blocking the agreements (a post from TeC, the blog of CMCC);
- Slides (pdf) about the research “Sharing Global CO2 Emission Reductions Among One Billion High Emitters”. From the presentation made by Massimo Tavoni at the 2009 International Energy Workshop
- Chakravarty, S., A. Chikkatur, H. de Conink, S. Pacala, R. Socolow and M. Tavoni (2009) “Sharing Global CO2 Emission Reductions Among One Billion High Emitters”, Proceedings of National Academy of Science, vol. 106 no. 29 11884-11888 [↩]
- In what follows we present results for an elasticity between income and emissions equal to 1. The interested reader is referred to the cited paper for an extensive investigation of the role of this parameter, where we show that the main results are robust to different specifications. [↩]
- Our paper includes an
analysis of global poverty alleviation which we do not reproduce here. Our principal conclusion is that if extra CO2 emissions were allocated to the one-third of the world’s population whose emissions are less than approximately 1 tCO2/person, the global population that is the subject of the Millennium Development goals, the incremental task for the upper two-thirds of the world’s emitters would be only marginally bigger. We conclude that whenever low-carbon technologies that raise the living standards of the world’s poorest people are more expensive than fossil-fuel alternatives, the latter should be chosen. In short, climate and poverty alleviation can and should be dealt with separately. [↩]
- Sharing Global CO2 Emissions Reductions Among One Billion High Emitters,a reasearch carried out by a group of reserachers at Princeton University, is included in Time magazine’s invention top list of the year. According to Time’s article: “Negotiations over carbon emissions resemble the end of a Quentin Tarantino film when everyone has a gun pointed at everyone else and no one can make a move. (…) A strategy focused on rich individuals instead of rich countries might just get us out of this”. [↩]