Study on the Concept of Per Capita Cumulative Emissions and Allocation Options

Transcription

1 ADVANCES IN CLIMATE CHANGE RESEARCH 2(2): 79 85, DOI: /SP.J POLICY FORUM Study on the Concept of Per Capita Cumulative Emissions and Allocation Options Shengmin Yu, Xiang Gao, Cuimei Ma, Lihua Zhai Energy Research Institute, National Development and Reform Commission, Beijing , China Astract Gloal long-term emission reduction targets need well defined options for equitale allocation of greenhouse gas emissions. Scholars from developing countries put forward the concept of equitale per capita cumulative emission rights. There are four possile operational definitions resulting from this concept. These potential options for allocation of emission rights are expressed with mathematical equations. Through simple simulation, this paper reveals the advantages, disadvantages and characteristics of each option. Keywords: climate change; gloal long-term target; per capita historical cumulative emission right; equitale allocation Citation: Yu, S., X. Gao, C. Ma, et al., 2011: Study on the concept of per capita cumulative emissions and allocation options. Adv. Clim. Change Res., 2(2), doi: /SP.J Introduction The IPCC Assessment Reports on climate change and greenhouse gas (GHG) emissions have promoted the universal adoption of the United Nations Framework Convention on Climate Change (1992) and the Kyoto Protocol (1997) under the United Nations. The ultimate ojective of the Convention is to stailize GHG concentration in the atmosphere at a level that prevents dangerous anthropogenic interference within the climate system 1. To achieve this ojective, general consensus in the inter-governmental climate change negotiations have already focused on holding the increase in gloal average temperature elow 2 C aove pre-industrial levels 2. Since deep cuts in gloal emissions are required to realize this 2 C goal [IPCC, 2007], the remaining GHG emission space in the atmosphere is a rare resource in the future. Therefore, countries are arguing against each other in the current negotiations for a fair and equitale access to the gloal emission space. To help resolve this dispute, the academic community has put forward various kinds of allocation proposals. Further, studies on sharing the urden of emission reductions, dominated y scholars of developed countries, contriute strongly to the current negotiations. However, Ding et al. [2010] identified various pitfalls and inequalities in such allocation schemes. To safeguard legitimate development rights of developing countries, scholars of these countries call for a quantification of historical differentiated responsiilities on GHG emissions and advocate allocation of the remaining caron udget according to Received: 21 Decemer 2010 Corresponding author: Shengmin Yu, yushengmin@eri.org.cn 1 Article 2 of the United Nations Framework Convention on Climate Change 2 In international climate change negotiations, no more than 2 C rise of gloal average temperature compared with that of preindustrialization period has gained strong consensus. The Copenhagen Accord in 2009 and the Cancun Agreement in 2010 have reconfirmed this consensus 1

2 80 ADVANCES IN CLIMATE CHANGE RESEARCH the criteria of population and the climate emission dets of developed countries 3. Building on these ideas, Chinese scholars [Ding et al. 2009; He et al., 2009; Pan and Chen, 2009; Pan and Zheng, 2009; RGDRCSCC, 2009] put forward the concept of per capita historical cumulative emission rights. They argued that any fair and equitale allocation scheme of gloal emission space shall guarantee equal or convergent per capita cumulative GHG emission rights for all nations, in an agreed time frame from a certain past year to a certain future year. To operate the concept of equitale per capita cumulative emission rights, countries would at first agree on a long-term stailization ojective, next define a gloal emissions trajectory leading to this agreed ojective, and then allocate emissions along that trajectory among countries ased on the criteria of equitale per capita cumulative emission rights. One fundamental step is to properly calculate per capita cumulative emissions for each nation in the pre-set time frame, which is not easy as population keeps changing over time. Seeing that some studies [Pan and Chen, 2009; WBGU, 2009] prefer to employ the so-called freezing population approach to calculate per capita cumulative emission, we elieve it is not appropriate as the freezing population approach deprives the emission rights of vast numers of population growth after the population cut-off year. The current study analyses four kinds of operational definitions of the concept of equitale per capita cumulative emission rights taking into account the reality of population change, resulting in four possile emission rights allocation options. Finally, this paper discusses the advantages and disadvantages of the four options with simulation and mathematical analyses, and identifies their influences in emission rights of China. 2 Options to operate the concept of per capita cumulative emission rights and the associated allocation formula In sight of the dynamic change of population, we can formulate at least four possile definitions of per capita cumulative emissions, lead to the following four possile options to operate the concept of equitale per capita cumulative emission rights. 2.1 Option 1: Sum of annual per capita emissions Here, per capita cumulative emissions are defined as the sum of annual per capita emissions from the starting year to the last year of the pre-set time frame. So the principle of equitale per capita cumulative emission rights means that the sum of per capita emissions in the pre-set time frame has to e equal for all nations [Bode, 2004]. For any country the following equation (1) is used. E i (t) P i (t) = Tc P (t) (1) Where t is each year, ranging from the starting year T to the end year T c of the pre-set time frame for the allocation program, E i (t) is the GHG emission of country i in year t, is the gloal GHG emission in year t, P i (t) is the population of country i in year t, and P (t) is the gloal population in year t. As the pre-set time frame starts from the past and ends in the future, population for each nation and the gloal include real population data and ex ante projections. While the gloal per capita cumulative emissions for the whole pre-set time frame is calculated as the enchmark, the per capita cumulative emissions of any country should not exceed this enchmark. Annual testing at egin of each year after the entry-into-force year T 0 of the allocation program would e employed to insure this rule. For each nation under test, we can trace its actual trajectory of per capita emissions from the starting year of the pre-set time frame till the testing year, y simply assuming that this nation s per capita emissions will converge linearly at E(T c) P (T c ) during the remainder of the pre-set time frame, we can calculate this nation s per capita cumulative emissions for the entire pre-set time frame. If this value exceeds the enchmark, the per capita emissions of this country under test are required eing reduced linearly down 3 The Sixth Meeting of AWG-LCA held the Technical Briefing on Historical Responsiility as a Guide to Future Action to Address Climate Change on June 4, The delegates from developing countries including China and India suggested addressing the issue of common ut differentiated responsiility and curing gloal GHG emissions in terms of per capita cumulative emissions. Their presentations are availale on hoc working groups/lca/items/4891.php

3 Shengmin Yu et al. / Study on the Concept of Per Capita Cumulative Emissions and Allocation Options 81 to E(T c) while its emission quota for every year since P (T c ) then is multiplied y the projected population for each year. If it does not exceed the enchmark, no constraints will e imposed on the country for the coming year. 2.2 Option 2: Quotient of cumulative emissions and cumulative population Per capita cumulative emissions are here defined as the quotient of cumulative emissions for each country and its cumulative population within the pre-set time frame. Based on this definition and the principle of equitale per capita cumulative emission rights, for any country the following equation (2) is used. E i (t) t=t = P i (t) P (t) (2) Equation (2) implies people (wherever and whenever they live) enjoy the same emission rights per year. Therefore, for each nation i, its deserved emission rights for the whole pre-set time frame are calculated as follows. t=t E i (t) = P T i (t) (3) c P (t) Here, we define the disposale remaining emission quota Q(i, T ) of the country i at the year T (T 0 T T c ). The quota is equal to its deserved emission rights minus the emissions which already occurred from the starting year T to the year T. Q(i, T ) = E i (t) T E i (t) (4) The disposale remaining emission quota Q(i, T 0 ) of the country i at the entry-into-force year T 0 is then estimated in accordance to the following formula. t=t Q(i, T 0 ) = T 0 P T i (t) E i (t) (5) c P (t) 2.3 Option 3: Every year each person in any country enjoys the same emission rights equivalent to the gloal per capita emissions for that year In option 3, the principle of equitale per capita cumulative emission rights is defined as that each person in any country in year t enjoys the same emission rights equivalent to the gloal per capita emissions for that year, i.e., the deserved emission rights of any country i for the whole pre-set time frame are equal to the sum of products of the gloal per capita emissions and a dynamic population of that country. E i (t) = ( ) P (t) P i(t) (6) The disposale remaining emission quota Q(i, T 0 ) of each country is then estimated in accordance to the following formula. Q(i, T 0 ) = ( ) P (t) P i(t) T 0 E i (t) (7) 2.4 Option 4: Quotient of cumulative emissions of a country and a fixed population of a certain year Here the estimation of per capita cumulative emissions is defined as the cumulative emissions of a country divided y a fixed population of a certain year. Based on this definition and the principle of equitale per capita cumulative emission rights, the following formula is used for any country i. E i (t) t=t = C (8) P i (T ) P (T ) where T is the population cut-off year, and populations are notionally freezing population for years eyond the cut-off year at the values for the year T. Note that this assumption does not necessarily mean there is no population change eyond the cut-off year, it merely implies that any newly added population after the population cut-off year will not e granted any emission rights.

4 82 ADVANCES IN CLIMATE CHANGE RESEARCH Finally, the disposale remaining emission quota Q(i, T 0 ) of each country should e calculated according to the following formula. t=t Q(i, T 0 ) = T 0 P i (T ) E i (t) (9) P (T ) The suggestion of a freezing population comes from the Contraction and Convergence solution put forward y the Gloal Commons Institute [GCI, 1997]. Both the gloal caron udget ased on per capita cumulative emissions presented y Pan and Chen [2009] and the gloal emission udget ased on historical responsiility put forward y WBGU [2009] employ the freezing population approach. It is argued that the purpose of this freezing population method is to reduce any incentive for a particular nation to increase their population and therey their emissions allocation. 3 Simulation and comparison of options 1 to 4 The mathematical equations of the aove mentioned four options for per capita cumulative emission rights show the asic characteristics of each option. To evaluate the advantages and disadvantages of each option, a simple simulation is taken and the results are discussed. 3.1 Data sources and assumptions Input data for the simulation include population and emission data for each country and the world, as well as assumptions aout the pre-set time frame and the entry-into-force year of the allocation program. Referring to the assumptions aout the pre-set time frame and the entry-into-force year of the allocation program, it must e noted that the selection of the starting year T of the pre-set time frame has a great influence on the historical responsiilities of each nation on GHG emissions and their emission allocation. In the inter-governmental climate change negotiations at the Technical Briefing on Historical Responsiility as a Guide to Future Action to Address Climate Change held at the Sixth Meeting of AWG-LCA on June 4, 2009, India and China suggested to quantify historical differentiated responsiilities since 1850 when GHG concentrations egan to increase aove natural levels due to increasing influences of industrialization. Unfortunately, no population data for those years are availale. Here, for etter data support, we assume that the starting year of the pre-set time frame is 1900, the end year T c is 2050, while the year T 0 of the allocation program is 2013 which is just susequent to the first commitment period of the Kyoto Protocol. Population data P i (t) and P (t) for is estimated from historical population statistics from the Populstat wesite 4 ; population data for comes from the UN Statistics Division Demographic Yearook system since ; population projection for is taken from the UN median population forecasts (UN Department of Economic and Social Affairs, 2008). Whilst the UN data is availale in five year intervals, population values for other interim years are interpolated. Yearly emissions of the world and each country from the starting year T until the entry-into-force year are produced as follows. The data on gloal emissions and energy-related CO 2 emissions of 185 countries for , comes from the climate analysis indicator tools developed y the World Resources Institute 6. Emission data for is estimated y the time series extrapolation models, whilst the regression functions may e different for each nation depending on their emission trends from 1990 to Please note that in this simple simulation, only data on the energy-related CO 2 emissions is used to estimate the results of each option. This is ecause that among the six kinds of human-induced GHGs specified in the Kyoto Protocol, CO 2 (in particular resulting from human enery consumption) is the most important emission source with minimum uncertainty in data and has a close relationship with economic development. The gloal emission control pathway from the entry-into-force year to the end year ( ) 4 Population Statistics Historical Demography, http: // 5 United Nations Statistics Division, 6 Climate Analysis Indicators Tool (CAIT) Version 7.0,

5 Shengmin Yu et al. / Study on the Concept of Per Capita Cumulative Emissions and Allocation Options 83 is assumed ased on the 2 C threshold and the CO 2 emissions pathways of mitigation scenarios for a 450 µmol (mol CO 2 -eq) 1 stailization target recommended y the IPCC [2007]. Figure 1 shows the pre-set gloal energy emission control path and gloal per capita emission trajectory Option 1 fails to achieve the pre-set gloal emission control path Simulation results show that option 1 cannot achieve the pre-set gloal emission reduction path (Fig. 2). In particular, the sum of annual emission rights of each country will gradually reach and further exceed the gloal emissions limit, thus the original goal of limiting temperature rise will not e achieved. Based on this, option 1 is rejected. Options 2, 3 and 4 are ale to ensure that the sum of deserved emission rights of the countries for the whole pre-set time frame equals the total permitted caron udget in the same period, and that the sum of each country s disposal remaining emission quota equals the gloal remaining caron udget for the period from the entry-into-force year to the end year of the pre-set time frame. However, in order to strictly follow the pre-set gloal emission control pathway, additional measures are needed to restrain each country s annual emissions in option 2, 3 and 4. If the remaining emission quota Q(i, T ) of each country is taken as a weight to divide gloal annual emission quota E(T ) for each country as expressed in equation (10), the annual emission control targets for each country could e identified, and thus the pre-set gloal emission control path would e strictly followed. E i (T ) = Q(i, T ) Q(i, T ) E(T ), T 0 T T c (10) i Figure 1 The pre-set gloal energy emission control path and per capita emissions 3.2 Simulation results and discussions Figure 2 Outcomes of option 1 and the pre-set gloal energy emission control path The freezing population assumption in option 4 A prerequisite to any incentives for a particular country to delierately increase its population for additional emission rights is that the otained marginal emission rights for a neworn population e larger than the country s per capita emission level at the year when this person is orn. In addition, the cumulative emission rights accrued for the neworn population in their lifetime must e larger than their cumulative usiness as usual emission demand during the same period. Otherwise, this country must make extra reduction efforts for newly added population. However, the simulation shows that the marginal emission rights per new person per year for any country under option 2 range at aout 2.99 t CO 2. In option 3, this value decreases over time from 4.09 t CO 2 in 2013 to 1.31 t CO 2 in The results of the simulation reveal that only a few countries meet the prerequisite of stimulating population growth for additional emission rights in the early stage when the allocation program ecomes effective under a relatively strict gloal emission control path 7. The numer of these countries is likely to reduce over time, taking into account their increasing per capita emission demands 7 Gloal per capita energy-related CO2 emission has een rising over the past years to 4.38 t per capita in 2007 (to t per capita for Annex I parties and to 2.56 t per capita for non-annex I parties)

6 84 ADVANCES IN CLIMATE CHANGE RESEARCH versus the decreasing annual marginal emission rights per person. Therefore, the effects of incentives for population growth for more emissions allocation are overestimated y the freezing population assumption in option 4. In view of a significant increase in the world population due to non-climate change factors 8, these anticipated population growth are entitled to their deserved emission rights. Therefore, option 2 and 3 make more sense than option Analysis of the impacts on emission rights of each country for option 2 and 3 Option 2 implies that people, wherever and whenever they live, enjoy the same emission rights each year. Option 3 implies that every year each person in any country enjoys the same emission rights equivalent to the gloal per capita emissions for that year. Both options are ased on crucial reasons. If we only consider their impacts on emission rights of a specific country, it mainly depends on whether its population trajectory is consistent with the pre-set gloal per capita emission trajectory for the entire time period. For example, option 3 would give a country more emission rights in case that the two trajectories coincide with each other with increasing or decreasing trends. The disposale remaining emission quota of some major countries in estimated y options 2, 3 and 4 are shown in Tale 1. The findings show that China will receive more emission rights under option 3, followed y option 2. Option 4, which is ased on freezing population of each country at the values for the year 2012, gives the lowest emission rights to China, ecause of the emission rights of newly added population in China eing deprived notaly. This estimated deprivation of emission rights of a country that practices the world most rigorous irth control program questions the use of the freezing population assumption. Tale 1 also shows that, ased on equitale per capita cumulative emission rights, most developed countries, plus several non-annex I countries whose per capita emissions are already aove world average, would e allocated negative quantities of emission rights due to their high historical responsiilities. Though, lacking political acceptaility, these results offer another perspective for the political argaining process on the standard for fair and equitale access to the gloal atmospheric space. Tale 1 The disposale remaining quota of main countries during under option 2, 3, and 4 (unit: Mt CO 2) Country Option 2 Option 3 Option 4 USA 261, , ,072 Japan 11,543 10,929 16,849 UK 35,312 36,279 41,392 Germany 46,615 47,914 55,332 France 8,307 9,036 12,894 Canada 17,913 17,748 18,100 Australia 8,324 8,259 8,361 Russia 54,667 55,215 66,441 Mexico 15,040 16,153 18,651 South Africa 3,527 3,000 1,733 India 319, , ,985 China 276, , ,877 4 Conclusions The intergovernmental climate change negotiations support the political argaining and scientific studies for the standard for fair and equitale access to the gloal atmospheric space. Thus an allocation proposal for equitale per capita cumulative emission rights has een put forward y developing countries. The main feature of this proposal is that per capita cumulative GHG emission rights in an agreed time frame from a certain past year to a certain future year, has to e equal for all countries. Therefore proper calculation of per capita cumulative emissions for each nation in the pre-set time frame is fundamental for the allocation program ut not easily achieved as the population keeps changing over time. Taking into account the reality of population change, four kinds of operational definitions of the concept of equitale per capita cumulative emission rights are presented, resulting in four possile emission rights allocation options. Option 1 assumes that the sum of per capita emissions in the pre-set time frame has to e equal for all nations. Option 2 implies that people, wherever and whenever they live, enjoy the same emission rights per year. Option 3 assumes that every year each person in any country enjoys the 8 According to UN World Population Prospects: The 2008 Revision, world population in 40 years will rise from 6.9 illion to 8 11 illion y 2050 with a median at 9.2 illion

7 Shengmin Yu et al. / Study on the Concept of Per Capita Cumulative Emissions and Allocation Options 85 same emission rights equivalent to the gloal per capita emissions for that year. In option 4, the freezing population approach is applied, which implies that any newly added population after the population cut-off year has no emission rights. Simulations and mathematical analysis show that among the four possile options, option 1 must e rejected due to its design, as it fails to achieve the pre-set gloal emission control pathway. Under relatively strict gloal emission control path, option 4 is questionale due to over-estimated effects of incentives for population growth for more emissions allocation. Option 2 and option 3 are well explained. From the perspective of China, option 3 results in the highest emission rights, followed y option 2. Simulation results also show that ased on equitale per capita cumulative emission rights, most developed countries, plus several non-annex I countries whose per capita emissions are already aove world average, would e allocated negative quantities of emission rights due to their high historical responsiilities. Acknowledgements This study was supported y the 2009 special study project employing asic scientific research fund of the Academy of Macroeconomic Research of NDRC. Any opinion expressed in this paper is the personal view of the authors and not to e imputed to any other person or entity. All errors are the authors sole responsiility. References Bode, S., 2004: Equal emissions per capita over time A proposal to comine responsiility and equity of rights for post-2012 GHG emission entitlement allocation. European Environment, 14, Ding, Z., X. Duan, Q. Ge, et al., 2009: Control of atmospheric CO 2 concentration y 2050: A calculation on the emission rights of different countries. Science in China Series D, 52(10): , doi: /s Ding, Z., X. Duan, Q. Ge, et al., 2010: On the major proposals for caron emission reduction and some related issues. Science China Earth Science, 53(2): , doi: /s GCI (Gloal Commons Institute), 1997: Contraction and convergence: A gloal solution to a gloal prolem. Accessed html. Gao, G., 2007: Caron emission right allocation under climate change. Adv. Clim. Change Res., 3, S87 S91. He, J., B. Liu, and W. Chen, 2004: Analysis on the equity of gloal climate change issues. China Population Resources and Environment (in Chinese), 14(6): He, J., W. Chen, F. Teng, et al., 2009: Long-term climate change mitigation target and caron permit allocation. Adv. Clim. Change Res., 5, S78 S85. IPCC, 2007: Climate Change 2007: Mitigation of Climate Change. Contriution of Working Group III to the Third Assessment Report of the Intergovernmental Panel on Climate Change. Accessed Meinshausen, M., N. Meinshausen, W. Hare, et al., 2009: Greenhouse gas emission targets for limiting gloal warming to 2 C. Nature, 458, Miao, X., 1998: Study of per capita CO 2 emissions cumulation and their oligations according to the contriution value. China Soft Science (in Chinese), (9), Pan, J., 2008: Caron udget for asic needs satisfaction: Implications for international equity and sustainaility. World Economics and Politics (in Chinese), (1), Pan, J., and Y. Chen, 2009: The caron udget scheme: An institutional framework for a fair and sustainale world climate regime. Social Sciences in China (in Chinese), (5), Pan, J., and Y. Zheng, 2009: Responsiility and individual equity for caron emissions rights. World Economics and Politics (in Chinese), (10), RGDRCSCC (Research Group of Development Research Center of the State Council of China), 2009: Emission reduction of greenhouse gas: Theoretical framework and solution scheme. Economic Research Journal (in Chinese), (3), UNDESA (United Nations Department of Economic and Social Affairs), 2008: World population prospects: The 2008 revision population dataase. Accessed WBGU (German Advisory Council on Gloal Change), 2009: Solving the climate dilemma: The udget approach special report. WBGU, 54pp. XU, Y., and J. He, 2000: Equity in the context of gloal climate change: A critical review. World Environment (in Chinese), (2),