International burden sharing in greenhouse gas reduction

THE WORLD BANK SECTOR POLICY AND RESEARCH STAFF Environment Department International Burden Sharing in Greenhouse Gas Reduction AmWf GriObler Nebojia Nakdmenovid November 1992 Environment Working Paper No. 55 Iis pr has been prepared for internal use. The views and interpretations herein are those of the author(s) and abould not be attributed to the World Bank, to its affiliated opnizations or to any Individual acdg on their behalf ACENOWL3DOEMBMW We gratefully acknowledge the support of the Environmental Policy and Research Division of the World Bank, Washington, D.C., for the research reported here. In particular, we would like to thank Mohan Munasinghe and Kenneth King for their intellectual encouragement and helpful suggestions which led to this study. Sincere thanks go also to 11'dar Karimov for his skillful contribution to the development of the Parametric Framework. *i ABTRWCT This report provides an overview of current and historical greenhouse gas (GHG) emissions; examines alternative formulations on how efforts to lower anthropogenic GHG emissions could be shared among regions/countries; evaluates quantitatively the implications of alternative GRG allocation/reduction criteria, particularly from the "North-South" perspective; and describes a combined GHG emission data base and software tool developed for the analysis of GHG allocation regimes; the Parametric Framework. The Parametric Framework (in Lotus format) contains a data set comprising 13 world re-ions/countries, socio-economic background data, and three different types of greenhouse gases/sources: fossil fuel and industrial carbon dioxide (CO2) emissions, CO emissions from biota and land-use changes, and anthropogenic methane (CH4) emissions. Historical emission data span the period 1800 to 1988 for CO, and 1"50 to 1988 for CR4. In addition, the numerical routines necessary to calculate the quantitative implications of four alternative GHG allocation criteria (and their variants) are included. The Parametric Framework enables easy and straight- forward changes of data, control targets, and other salient parameters of importance in GHG accounting (e.g., global warming potential equivalences between different GHGs. Four different GHG emission reduction and allocation criteria are analyzed: equal per capita eLissions, equal percentage cuts from current emissions to desired target levels ("grandfathering"), cutbacks proportional to past contributions to atmospheric concentration increase on a regional basis (compensation for "natural debt"), and natural GHG sinks adjusted emission reduction. An analysis was made of the quantitative implications of the four GHG emission allocation criteria for 13 world regions, assuming a reduction of global emissions to 4 Gt C (C-equivalent) by the year 2050. Additional sensitivity analyses were performed for each of the criteria. The most important findings of the analysis include the following: (1) There are two generic classes of allocation criteria: distributive - the allocation of emission rights, and reductive - the allocation of emission reduction requirements. The largest differences in emission allocations are obtained between these two classes, especially when distributive allocation criteria are based on a per capita basis. (2) Differences were smaller within each of the two classes. For example, the reductive allocation criteria across the board percentaae cuts ("arandfatherina") and cutbacks proportional to past contribution achieve quite similar regional future emission allocations: (3) The basic principle of the allocation is also more important than the inclusion of different GHGs (comprehensiveness). (4) The smalle3t variations in emission distribution resulted from altering the reference year compared to which emission reduction ought to be achieved. ii ZIWVRNATIONAL BUDN 8R2NG EN an8imovs us8 REDUCWEON Table of Contents Acknowledgement . . . . . . . . . . . . . . . . . . 0. . . Abstract . . ... . ...................* * 11 1. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . 1 2. GREENHOUSE GAS EPISSIONS INVENTORY . .. . . . . . . 4 2.1 Carbon Dioxide (C02) . . . . . . . . . . . . . . . 10 2.2 Anthropogenic Methane Emissions . . . . . . . . . 22 2.3 CO2 and CB4 . . . . . . . . . . . . . . . . . . . 27 3. GREENHOUSE GASES REDUCTION CRITERIA . . . . . . . . . 32 3.1 Reduction Scenarios Based on Four Criteria . . . . 35 3.2 Equal Emission Rights Per Head . . . . . . . . . 36 3.3 Across-the-Board Percentage Cuts ("grandfathering") 40 3.4 Cutbacks Proportional to Past Contributions . . . 44 3.5 Sink Adjusted Emissions . . . ... . . . . . . . . 49 4. COMPARISON OF CRITERIA . . . . . . . . . . . . . . . . 53 5. CONCLUSIONS . . . . . . . . . . . . . . . . . . . . 63 REFERENCES .0 0 0 0 . . . . . . . 0 . . . . . 0 . 0 . . . 67 APPENDIX I - Numerical Appendix . . . . . . . . . . . . . . 73 APPENDIX II - Data Appendix . . . . .. . . *. *. . .. . 81 APPENDIX III - Parametric Framework Software Appendix . . . 87 iit INTERNATIONAL BURDEN SHARING 1N GREENHOUSE GAS REDUCTION 1. Introduction Future climate change was one of the central issues of the 1992 UN Conference of Environment and Development (UNCED) held in Rio de Janeiro. Expectations were high that the Global Summit would result in an international agreement to counter the risks of adverse conse- quences of global climate change. In fact, a Framework Convention on Climate Change negotiated by the Intergovernmental Negotiating Committee (INC) was signed, but without quantitative emission tar- gets and dates. Should binding targets be agreed upon in the future, these would have important distributional consequences. Targets also imply a prior agreement on the degree of comprehensiveness in covering different greenhouse gases, and agreement on the principles for deriving target levels. This paper illustrates the quantitative implications of precisely these central issues surrounding an international agreement. For several years the prospects of global warming have been on the agenda of the Intergovernmental Panel on Climate Change (IPCC) that has inter alia further extended our scientific knowledge in this area and has also developed a number of scenarios describing possible future developments of global GHG emissions. Under a "business-as-usual" scenario GHG emissions increase unconstrained throughout the 21st century leading to nearly a tripLng of the equivalent CO2 concentration in the atmosphere by the year 2100 (Figure 1.1). The IPCC (1990) estimates that under such a scenario global mean temperature would increase by 0.3 degrees Celsius per decade to reach a value of about 4 degrees (uncertainty range 3 to 6 degrees) higher than pre-industrial levels by the end of the 21st century. in order to illustrate possible pathways to mitigate the risks of global climate change, the IPCC has also developed alternative scenarios leading to a stabilization of atmos- pheric GHG concentrations (Figure 1.1) by the second half of the 21st century as the result of a significant reduction in GHG emissions (Fig- ure 1.2). In particular, the Accelerated Policies Scenario (Scenario D in Figure 1.2), defines a development path in which current global GHG emissions are approximately halved by the year 2050. In the meantime, a new range of emission scenarios have been developed by the IPCC (1992) without, however, narrowing down the gap between high and low emission paths. In view of the large degree of scientific uncertainty that surrounds the effects of global warming, the precautionary principle would deem emis- sion reductions as a prudent response to the potentially adverse -2- 10. BUSINESS- AS-USUAL 11200O E B m m 0> z - I560 > r 0 4 : am O0 SCENARIO D z- 00 0-1 . . . . , , - - ,. - 280 - 1900 1950 2000 2050 2100 YEAR Figure 1.1 Increases of global GHG concentrations (expressed as equivalent C02 concentration) and resulting changes in radiative bal- ance (in Natt per m2) for selected IPCC scenarios. Source: IPCC, 1990. consequences for humanity as a whole. Achieving reductions, especially drastic ones, is indeed a formidable task considering that developing countries especially need increases in energy services and other activi- ties that result in GHG emissions. The salient questions are how such reductions might be achieved and by whom, and what the various effects (economic, ecological, distributive, etc.) of such reductions might be. In other words, how is the burden of global emission reduc- tion going to be shared, and what could the criteria be for such burden sharing that would be fair and thus agreeable to all parties. Of crucial importance in this context is the large disparity between the more developed and the developing countries. The former are responsi- ble for about 80 percent of global emissions with only 20 percent of world population. More developed countries are also responsible (on a differentiated bases) for the bulk of historical increase in anthropogenic GHG concentrations. Conversely, developing countries will become more important contributors to future GHG emissions, independent from the issue of how high or low global GHG emissions will actually turn out to be. -3- w a BUSINESS- x AS-USUAL 0 201 zo 0 MO M If- SCENARIO Z 10 1980 2000 2020 2040 2060 2080 210 YEAR 900 BUSINESS- Z j 800 AS-USUAL > 700 W C 600 SCENARIO B 5 500 Ts SCENARIO C 400 300SCENARIO D 300 - " . &" .8 1 ' 1980 2000 2020 2040 2060 2080 2100 YEAR Figure 1.2 Range of IPCC emission scenarios for C02 (top) and methane (bottom). Scenarios B, C, and D represent varying degrees of mitigation measures. Source: IPOC, 1991. In this report, we analyze the distributional consequences of four different allocation criteria that have been proposed in the literature. Some of them have also been mentioned during the INC process for possible inclusion in the Framework Convention. The criteria exam- ined include equal percentage cuts for all regions, cuts that are propor- tional to the historical contribution of different regions to the -4- greenhouse effect, equal per capita emissions throughout the world, and the allocation of "natural" sinks of GHGs among different regions. The analysis is based on 13 exhaustive world regions and covers the time period to the middle of the next century. It includes all anthropogenic sources of CO2 and CH4. The report is based on the assessments made with the help of the Parametric Framework, a formal model described in an appendix to this paper. 2. Greenhouse Gas Emissions Inventory Atmospheric trace gases help regulate the temperature regime of the earth. Incoming solar radiation warms the surface of the planet. Part of the reemitted radiant heat is trapped by trace gases in the atmo- sphere producing the greenhouse effect. Without it, temperature on earth would be some 30 degrees Kelvin lower and life impossible. This natural greenhouse effect is also involved in governing the temperature balances of the neighboring planets Venus and Mars. The most important infrared-absorbing greenhouse gases in the earth's atmosphere are water vapor and carbon dioxide (CO), which account for over 90 percent of the natural greenhouse effect. Table 2.1 summar- izes the relative contributions to the natural and anthropogenic green- house effect of different gases and gives their respective concentrations and rates of increase. Since the onset of the Industrial Revolution, human activities have not only increased the atmospheric concentration of naturally occurring greenhouse gases like C02 and methane (CH4), but have also added new ones such as chlorofluorocarbons (CFCs), which additionally deplete the stratospheric ozone layer. Human activi- ties have altered the concentrations of greenhouse gases both directly by anthropogenic emissions of C02, CH4, nitrous oxide (N20) and OCs, and indirectly by influencing the complex atmospheric chemis- try, resulting in increases of stratospheric water vapor concentrations, depletion of stratospheric ozone (0) and increases of ozone concentra- tions in the lower levels of the atmosphere (increase in tropospheric ozone). The combined effect of the anthropogenic increase in the concentration of greenhouse gases (GHGs) is estimated to amount to a temperature increase of some 2 to 3 degrees Kelvin over the 1860 to 1980 period. That actual global mean temperature rise was much lower (0.5 degrees Table 2.1. Greenhouse gases and their effect. Sources: IPCC, 1990; German Enquete Commission, 1991. CO2 CH4 N20 CFCs O H20 % contribution to greenhouse effect Natural 28% 2% 2% - 8% 70% (309 K) Anthropogenic 1860-1980 60% 14% 3% 9% 10% 4% (2-8* K) Contribution of 1990 emissions over the 61% 15% 4% 11% others: 9%a next 100 years Trace gas concentration 106 ppt 103 ppt 103 ppt ppt parts per trillion (1012) Pre-industrial 280 800 288 0 Current 853 1720 310 280-484b Increase since 1800 73 920 22 280-484b (In %) (26%) (115%) (7.6%) (oo) Current Increase/yr 1.8 15 0.8 9.5-17b (In %/yr) (0.5%) (0.9%) (0.25%) (4%) Residence tIne 50-200 10-14 150 65-.130b 0.1 yrs _ _________ a) Including stratospheric water vapor, ozone and HCFCs. b) Range corresponds to CFC-11s and CFC-12s respectively. -6- K, or perhaps even smaller) can be attributed to a large number of yet insufficiently understood processes like the thermal inertia of the oce- ans, complex interlinkages and feedbacks between different GHGs, and a variety of counterbalancing trends. For instance, recent findings from the Intergovernmental Panel on Climate Change (IPCC, 1992) indicate that possibly as much as 40 percent of the theoretical addi- tional warming of the northern hemisphere was compensated for by the cooling effect of increasing concentrations of stre.ospheric sulfate aero- sols resulting from rising emissions of sulfurous compounds from the use of fossil fuels. Previously this was thought to have only local (smog) and regional (acidic precipitation) environmental impacts. Recent IPCC findings (not yet reflected in Table 2.1) also indicate that the net warming effect of increasing CFCs concentration may have been bal- anced by corresponding decreases in stratospheric ozone. Conversely, the future phase out of CFCs under the Montreal and London Proto- cols may not produce any reduction of global warming due to this com- plex interplay between the different GHGs (IPCC, 1992). The effect of changing concentrations of greenhouse gases on climate depends on the respective radiative forcing of the different greenhouse gases, i.e. how a changing concentration of a given GHG modifies the balance between incoming and outgoing radiation of the climate sys- tem. There are both direct (e.g. changes in the radiative balance through changes in concentration of a particular GHG) and indirect effects (e.g. the formation of other radiatively active gases, such as ozone from CH4 emissions, and influences on the atmospheric residence times of other GHGs). How long these effects will last depends in turn on the residence time of the respective GHG in the atmosphere (Table 2.1), before being absorbed by terrestrial sinks and/or destroyed by chemical reactions in the atmosphere. Combining radiative forcing with atmospheric residence times (particularly for CO2 still affected by considerable uncertainties of the global carbon cycle) allows to compare the "global warming potential" of different GHGs. For instance, in this paper a global warming potential value equivalent to 21 (direct and indirect effects combined) between CO2 and CH4 on the basis of the relative mass of the two gases has been adopted. -7- Thus, the emission of one additional kg OH4 corresponds to 21 kg of additional C02 emissions.* A sensitivity analysis in varying this methane equivalence factor (among other CH4 accounting variables) is performed in chapters 3.3 and 3.4 below. Instead of an exogenously fixed residence time for C02, a dynamic model is used to translate emissions to atmospheric concentration increases (for details see Grdbler and Fujii, 1991). The methane equivalence value used here can be compared to the global warming potential of CH4 relative to C02 for a 100-year time horizon as presented in the 1990 IPCC report. This value can be easily changed to any desired value within the Parametric Framework developed for this study. About three quarters of the potential greenhouse effect from anthropo- genic emissions over the 1860 to 1980 period and of current (1990) emissions over the next 100 years (Table 2.1.) are accounted for by increasing concentrations of two greenhouse gases: carbon dioxide and methane. Considering the comparatively modest contribution of N20, which has been revised downwards by a factor of three by the IPCC (Bolin, 1991), and the above discussed possible overall zero-warming balance of increasing CFCs concentrations due to ozone feedbacks, car- bon dioxide and methane remain by far the dominant anthropogenic greenhouse gases. This is the reason why in the following sections of the report we concentrate on current and historical C02 and CH4 emis- sions.** Most human activities cause CO2 and CH4 emissions and these vary widely in space and over time. Anthropogenic sources include the combustion of fossil fuels, deforestation and land-use changes, agricul- ture and a variety of industrial processes. Contributions to emissions * Note that this factor Is based on a mass equivalent, and not on a mole equivalent basis. By convention, the kg CO-equIvalent of methaue expressed as kg O-equivalent. The ffect of different assumptions of the equivalence between C0, and CB4 emissions can be easily calculated with the Parametric Pramework developed for this report, where the global warming potential mame equivalence of methane is a free paranse- ter value (ragms between 9 and 0a have been presented In the 1990 WOO report). Generally, lacreasg the methase equivalence factor will Increase the relative Importance of methans emissions (and thus of non- Industrial emisslon sources, particularly Important In developing countrie) compared to CO, aniselons (donated by feesll fuel se with larger shares of ladustrialised countries). There emain serious erva tions agaist using equivalence factors that do not take Into account the signlficant diference In residence time betwen C0s (several decades to centuries) and C4 (about one decade). Instantaneous forcing equivalences (Hammond et al., 1990) or similar OGreenhouse ladoxes' as for lastance used In the 1990 report of the World Resources lastitute (WRI) remain highly controversial both In the scientific and policy com- mUnities. *An additional reason for not considerlng NlO sad CFs emissions are the signifcant sucertainties in sources and levels of current emissions (N2O), and In reglilly disaggregated historical eaaulon data series (or activity level d&.ta from which these could be Iaerred from) for both N2O and CFCO. -8- by greenhouse gas, sector, or region vary significantly and change over time. GHG emissions are influenced by differences in population size, climatic conditions, settlement patterns, levels of affluence, and struc- ture of the economy. Furthermore, the type and extent of GHG emis- sions are frequently the result inter alia of: the degree of economic development (e.g. although deforestation is currently primarily a phenomenon in the tropics, it mirrors similar large-scale land transfor- mations that took place in the northern hemisphere many decades to centuries ago); the historical development trajectories (as reflected for instance in the differences between spatial and industrial structures even for comparable levels of per capita income); and the type and efficiency of practices and technologies applied both in agriculture and industry. These complexities have to be borne in mind, especially when comparing different GHG emissions between regions and over time, and in relating emissions to size of population or levels of economic activi- ties. Finally, significant uncertainties in the emission estimates reported here have also to be mentioned. Only fossil fuel CO2 emission estimates can be considered as quite accurate. For other sources of C02 (deforesta- tion and land-use changes) uncertainties in global budgets, and even more so in regional/national estimates, are substantial (sometimes by up to a factor of five). Methane emissions by type of activity and by region are also uncertain. In general, emission estimates inevitably have to combine "hard" data based on detailed statistical sources, con- sistent data gathering methodologies, and a good understanding of the physical/chemical processes leading to emissions, with uncertain esti- mates, sometimes even zero-order approximations. For many GHG emission sources data on activities leading to emissions (e.g. activities outside industry or even outside the formal economy like subsistence farming) are lacking, observational records and their interpretation remain fragmented and controversial (like satellite surveys of tropical deforestation), or the linkage between human activities and GHG emis- sions is poorly understood scientifically (e.g. CH4 emissions from rice production) and estimated emission factors based on a few observa- tional records (or laboratory experiments) only. In a worst case (as for tropical deforestation), all three uncertainty factors are combined. The objective of this paper is not to estimate new data sets on histori- cal and present GHG emissions or to preempt the emergence of scientific consensus. Instead, existing data sets available in the public -9- domain and asbembled by the authors over the last few years were used primarily to elucidate the impacts and trade-offs inherent in different GHG allocation and emission reduction regimes. Thus, some of the data are inherently uncertain and are provided for illustrative purposes only. Despite the large uncertainties, the data set used in this paper and available in conjunesion with the Parametric Framework is useful because it ensures comprehensiveness, consistency and reflects scientific uncertainties. For example the data set fulfills the following criteria: 1) comprehensive coverage of both historical and current C02 and CH4 emissions at a disaggregation level of 13 regions/countries; 2) global emission budgets consistent with the ranges emerging as scientific con- sensus, in particular within the IPOC; and finally, 3) where uncertain- ties of both sources and sinks of anthropogenic GHGs result in large ranges of emission estimates, rather conservative, lower range values are adopted. The latter assumption is b.'sed on the premise that high emission estimates, in particular from biotic C02 sources, are incon- sistent with the current consensus of the size of the respective sinks and the measured atmospheric concentration increases. In other words, very large biota C02 emission estimates complicate the problem in that a "missing carbon sink" is required to accommodate the measured record of atmospheric CO2 concentration increases, whereas lower biota emission estimates are within the range of current consensus on the order of magnitude of the global oceanic carbon sink. The sources and assumptions underlying the data base of historical and present anthropogenic 002 and CH4 emissions are detailed in the data appendix. The data base includes (where appropriate) emissions of fos- sil fuel (coal, oil and gas), other industrial (cement manufacture, gas flaring) CO, and biota (deforestation and land-use rhanges) C02 for 13 world regions over the period 1800 to 1988. Anthropogenic methane emissions were estimated for 13 world regions over the period 1950 to 1988 only, due to the short residence time of methane in the atmo- . sphere of about 10 years. Thus, contrary to CO , pre-1950 OH4 emis- sions do not contribute any longer to current atmospheric concentra- tions. In addition to GHG emission data, the data base includes histor- ical and projected population data for 13 regions/countries for the period 1800 to 2100. Additional socio-economic data (size of region/country, GDP, and size of adult [i.e. over 18 years of age] popu- lation) are included for consideration as additional variables in possible GHG allocation/reduction regimes and/or as further background infor- .nation (for data sources cf. the data appendix). -10- It was not the purpose of the present paper to elaborate a new GHG emission inventory. For that the scientific uncertainties in sources and sinks of GHG are still too large. Consequently, the following discussion of emissions by gas, source and regional disaggregation have to be con- sidered only as indicative and open to revisions with increasing scientific certainty and availability of better data, though this process is likely to take considerable time and research effort. The layout of the data base in the form of an easy to use Lotus spreadsheet format and the open architecture of the Parametric Framework used for the calculations presented below, was designed to facilitate the process of a critical discussion of emission data, inclusion of alternative data series, and for performing sensitivity analysis. Critical discussion and per- manent reevaluation of GHG emission data are and will continue to be a central issue in any possible climate stabilization regime. 2.1. Carbon Dioxide (CO) After water vapor, carbon dioxide is the most abundant and the single most important anthropogenic greenhouse gas. Currently the atmo- sphere contains some 750 gigatons of carbon (Gt C)* corresponding to an atmospheric concentration of 353 ppmv (parts per million by volume). Anthropogenic emissions in the late 1980s are estimated to range between 5.8 to 8.7 Gt C (IPCC, 1990) annually, and the build-up of atmospheric concentration amounts to some 3.4 Gt C or 1.8 ppmv annually. This implies that the global carbon sinks (the oceans and the terrestrial biosphere) take up approximately between 40 to 60 percent of the emitted CO. Consequently, between 60 to 40 percent of the emissions remain as "airborne fraction" in the atmosphere resulting in the observed atmospheric CO2 concentration increases. The most important sources of CO2 emissions are the burning of fossil fuels, deforestation and land-use changes (CO2 release from burning of forest biomass and carbon releases from disturbance of the soil carbon con- tent due to changing vegetation cover). Whereas industrial C02 emis- sions (mostly fossil fuels) are known fairly accurately (within perhaps 10 percent) to amount to some 5.7 Gt C in 1988, there is considerable uncertainty in the amount of gross and net releases of C02 from deforestation and changing land-use patterns (Pee discussion below). * By convention, CO emiselons and concentntlon are expressed In the mass of carbon contained In the pas only. To convert to total Gt COs multiply by 3.66 (44/12). - 11 - 2.1.1. Industrial Sources of CO2 Emisslons Industrial sources of CO2 emissions are dominated by the combustion of fossil fuels, the largest single source of GHG emissions. Worldwide, currently some 5.5 Gt C emissions result from the burning of fossil fuels (Table 2.2). Conversely, C02 emissions from cement manufacture and gas flaring combined are, with 0.2 Gt C emissions, comparatively small. Industrial CO emissions are the best quantified of all GHG emissions as they can be derived straight from available detailed energy consump- tion statistics. Here we have adopted the emission data elaborated by Oak Ridge (Marland et al., 1989) for the period since 1950 based on UN energy statistics. Yearly emission data by country from consump- tion of coal, oil and natural gas, from gas flaring and cement manufac- ture have been aggregated to the 1 regions used within the Parametric Framework. For years prior to 1950, earlier IIASA work* as well as additional historical statistics on the long-term evolution of energy con- sumption at the global and national level served as the basis to derive historical industrial CO2 emission estimates (cf. discussion in the data appendix). In addition to fossil fuel use, biomass energy like fuelwood, if not harvested on a sustainable basis, is also a net contributor to the C02 build-up in the atmosphere, however, its order of magnitude is much smaller than fossil fuels. Estimates indicate (gross) emissions of some 0.4 Gt C from fuelwobd burning in the 1980s (Houghton, 1989). Releases from unsustainable fuelwood harvesting are obviously much smaller than the total 0.4 Gt C and are included in the biota sources of CO2 emissions discussed below. From fossil fuels, the largest contributor is coal accounting for some 44 percent of fossil fuel CO2 emissions. Although coal only accounts for 31 percent of the global fossil energy consumption (and 27 percent in total commercial energy consumption), its share in CO2 emissions is much larger due to its higher carbon to hydrogen ratio. For delivering 7 mil- lion kcal energy (equivalent to one ton coal equivalent, or tee), combus- tion of coal releases 680 kg of carbon, compared to some 520 kg to deliver the same amount of primary energy by crude oil. Natural gas (mostly methane) has the lowest carbon emissions per unit energy (some 410 kg C per tce, or only 60 percent of the emissions of coal), pointing to the significant potential of interfuel substitution in carbon emission reduction strategies (cf. Ausubel et al., 1988). * Mactti and NAzIovid, 1979; Naklenovi, 1984; Nakdenovid, 1988; GrIbler and Nakienovid, 1988; Asbel st aL, 1988; NaMidenomM at aL, 1990; Fil, 1990. - 12 - Table 2.2. Industrial C02 emissions in 1988 (Gt carbon). Source: Mar- land et al, 1989. World Total "North "South- (regions 1-8) (regions 7-13) Gt % Fossil fuel combustion coal 1.61 0.79 2.41 42.3 oil 1.59 0.56 2.15 38.0 gas 0.78 0.14 0.91 16.1 cement 0.08 0.07 0.14 2.5 manufacture Flaring of 0.01 0.04 0.05 0.9 natural gas Total industry 4.07 1.60 5.66 100.0 The structure of the fuel mix (also including zero-carbon energy forms like hydroelectricity and nuclear energy) explains part of the differences in energy-related C02'emissions. However, even more important are differences in population size, the degree of economic development, levels of affluence and consumption, and structure of economic activi- ties. These factors inter alia explain the large differences in industrial C02 emissions between regions and countries and in their specifc emis- sion values and intensities (Table 2.3). Industrial CO2 emissions are the most extreme case in aNorth-Souths disparities of GHG emissions. Twenty percent of the world's population emit almost 80 percent of global industrial CO2 emissions in producing (and con- suming) about the same percentage of the global economic output.* This disparity becomes even more accentuated when the differences in contribution to atmospheric concentration increases due to fossil fuel combustion is considered (cf. the discussion below). Thus, the levels, structure and etiology of emissions vary greatly between countries and regions. An additional complexity is also the extreme heterogeneity within and among regions with a similar degree of economic and industrial development. This is illustrated in Figure * Usg GDP based on market eachange rates as an Indicator. Based n GDP compared on purchasing power parities (PPP) basi, developed contries stil coasume about two-thirds (64 perent) of eunk output globaoy. Table 2.3. 1988 industrial C02 emissions: comparison of absolute and relative values (in Gigatons and tons carbon) Per land Per capita population Per unit GDP (1988) 1988 emissions area total adult market exch. PPP Gt C t C/km2 t C/cap t C/cap t C/1000 t C/1000 1 OECD NA 1.43 74 5.28 6.80 0.27 0.30 2 OECD EU 0.85 197 2.22 2.88 0.15 0.18 3 Eastern EU 0.36 396 3.17 3.94 1.48 0.65 4 USSR 1.09 49 3.88 5.21 1.86 0.04 5 Japan 0.27 714 2.20 2.85 0.09 0.17 6 Oceania 0.07 9 3.69 5.03 0.27 0.31 7 China 0.61 64 0.56 0.83 1.83 0.28 8 India 0.17 52 0.21 0.37 0.64 0.20 9 OtherAsia 0.18 20 0.21 0.38 0.22 0.10 10 NAME* 0.24 19 0.73 1.48 0.45 0.33 11 Other Africa 0.12 5 0.25 0.49 0.51 0.27 12 Brasil 0.06 7 0.41 0.69 0.17 0.10 13 Other LatAm 0.24 20 0.84 1.47 0.44 0.23 "North' (1-6) 4.07 74 3.41 4.45 0.27 0.30 uSouths (7-13) 1.60 20 0.41 0.70 0.54 0.21 World 5.66 42 1.11 1.77 0.32 0.27 2actor DIfference 23.8 145.7 25.1 18.9 20.7 8.5 smallest-highest *North Africa and Middle East -14 - 2.1, showing energy-related carbon emissions (by source) per capita for a number of countries or regions. For comparison, other anthropogenic sources of CO2 and methane emissions are also shown on a per capita basis. The height of each bar is proportional to the respective per cap- ita emissions, and the width proportional to the size of the respective population. Thus, the area of each bar indicates the relative magnitude of tht absolute emissions in each region. Figure 2.1 also shows the geo- graphical definition of the 13 world regions chosen for this study. On average, the industrial CO2 emissions per capita range between 3.4 tons C per capita in developed countries and 0.4 t C/capita in develop- ing ones, i.e. by a factor of eight. At the level of individual countries and regions the differences are even larger: per capita emissions vary by over a factor of 25 between the regions with the highest values (North America) and the lowest (India, and Asia outside China). Taking abso- lute emissions or emissions per GDP as an indicator, significant regional and national differences persist (cf. Table 2.3.). Even where per capita emissions are similar, they are often so for entirely different reasons: both the USA and the former GDR have per capita emissions in excess of 5 tons carbon per year. In the case of the USA, this is due to high energy consumption and energy-intensive lifestyles, such as high oil consumption for private transportation. In the former GDR, it is due to a different level and structure of the economy and its energy supply system, stressing the energy intensive basic material production sector and a high share of brown coal in the energy supply mix. Per capita emissions can also differ significantly for similar levels of affluence and degree of economic activities. For instance, Switzerland and the USA both have per capita GDP in excess of 20,000 US $(1988), whereas their per capita carbon emissions from fossil fuel use differ by nearly a factor of three (1.8 compared to over 5 tons carbon per capita for Switzerland and the USA, respectively). Since the onset of the Industrial Revolution some 200 Gt C have been emitted by industrial activities. The value adopted here is in good agreement with the estimates of the IPCC of some 195 Gt C over the period 1850 to 1986.* This is much larger than the estimated carbon release by deforestation and land-use changes over the same time period of some 117 (-:35) Gt C (IPOC, 1990). From all fossil fuels, the contribution of coal to atmospheric concentration increases is the *Not that the 200 Ot C of the Paramtkic Framework refers to the period 1800 to 1988. - 15 - Industrial C02and total* GHGs per capita emissions versus population Tons Ce/capita 6- 2- 0 ifou spopulation Legend: Ma Ali Gaso Oil coal *Incuding deforestation CO0and anthropogenic CH4eMisson (1kgMC-=21kg CH4) Figure 2.1 GHG emissions versus population for 13 world regions (in tons carbon equivalent per capita and million population). highest with 57 percent. Oil and natural gas follow with 30 and 20 per- cent respectively, whereas the contribution from cement manufacture and flaring of natural gas are modest with 3 percent.* The significant 'North-South' divide identified above in current indus- trial carbon emissions becomes even larger when considering their his- torical dimension: our estimates indicate that about 84 percent of the industrial CO2 emissions since 1800 still remaining in the atmosphere can be attributed to the emissions of presently industrialised countries. Conversely, the share of developing countries in energy-related atmos- pheric CO2 build-up is, with 16 percent, very low, especially when we consider that about 70 percent of the people that have lived on Earth * At the regional or national level, however natural gas Saring is an iutoricaly Important soume of carbon emiselons. por Iastance, ariag of naturalas in North Africa and the Middle East may have contributed as much as one quarter of the cumulative ladustrial carbon emios of that region. Flarlag (1.. wastae) of natural gas may have contribUted twice as much carbon emissions than the energ consumption of natural gas In the sane region. since 1800 reside(d) in the South. The upper part of Figure 2.2 summarizes the regional breakdown of current industrial 002 emissions, and the lower shows the contribution of each region to atmospheric concentration increases. The differences in current and historical shares of the "global warming pie between regions are an illustration of the implications of considering the actions of past generations in addition to the responsibilities to be assumed by present and future generations in climate change mitigation efforts. 2.1.2. Blota Sources Of CO2 EmissioUs Changes in the carbon balance of terrestrial vegetation and soils induced by human activities (land use changes, in particular deforesta- tion) are an additional significant source of 002 emissions. Since the pools and natural carbon fluxes in vegetation are large, it is difficult to estimate the exact order of magnitude of human impacts. The total amount of carbon stored in vegetation and soil amounts to some 2000 Gt C (600 Gt in vegetative mass and 1400 Gt C in soils), and net annual uptake (gross 002 uptake from the atmosphere minus CO2 respiration by plants) amounts to 50-60 Gt C annually, i.e. 10 times the industrial C02 emissions (IPCC, 1990). Changes in land-use pat- terns and vegetation cover are important because of the large differences in the carbon sequestered by different vegetation systems. The vegetation and soils of undisturbed forests can hold 20 to 100 times more carbon (per ha) than agricultural systems. Consequently, land- use changes can release significant biotic carbon sources to the atmo- sphere. Biota carbon emissions stem from the following factors: 1) burning Of biomass asoitdwith land-use changes, e.g. traditional slush and burn agriculture-, 2) organic decay of (remaining) biomass, especially after forest clearings; and 3) oxidation of soil carbon in conjunction with changing vegetation cover. Finally, oxidation of wood products (e.g. Faper) from forests add adiinlcarbon fluxes, whereas the regrowth of trees removes carbon from the atmosphere. Large uncer- tainties pertaining to biotic carbon fluxes are a result of: 1) the difficulty in estimating the oxtent (area) of land-wse changes (uncer- tainty ranges can be larger than :k50 percent), in particular from deforestation where problems arise in satellite monitoring and data Interpretation, and uncertainties about secondary uses of deforested -17- USSR . Nu"th Ameuia (2.2%) Eastern Europe S) MDC: 71.9% LDCs: 28.1% Ret of Latin Aeira 14.2%1 Brar.lt .0% Rest of Africa (2.1%) N. Africa & MId. East 14.3%) Western Europe (15.0%) Itestof Asa 12.8%) Ax, Japan 14.8%) Australia & 1. Zealand (1.3%) USSR 14.1%) Easter surope (SA%) N" Anwe 1332%) Rest of Latta Amica (32%) ItestlI I oAies& MiEast22%) MDCS:B3.7% RestolAalatt.%) LDCe: 10.% india itS%) Chin (SS%) Australia & IL Zealand i.M Japan it?%) Western Europe (26.1% Figure 2.2 Shares (in percent) of different regions in 1988 emissions (top) and in contribution to historical concentration increases over the period 1800 to 1988 (bottom) of industrial sources of CO2. - 18 - areas (forests, grasslands or agriculture); 2) ranges in estimates of the carbon content of biomass and especially of soils of disturbed areas (uncertainty ranges by approximately a factor of two); and 3) uncerti- tude about the response profile of terrestrial carbon pools to changes in land-use. For instance, only 50-60 percent of the annual biotic carbon flux of the early 1980s are calculated to have originated from deforesta- tion taking place during that period, with the remainder consisting of vegetation decay, and soil carbon releases from deforestation of previ- ous years. All these elements combined result in a uncertainty range of biotic carbon sources of up to a factor of four. The data uncertainty range is even more compounded when one considers that different esti- mates relying on the same models and the same sources of data for deforestation and carbon stocks yield very different results, and the rea- sons for such differences remain unclear (Houghton, 1991). For the early 1980s, the net carbon flux (deforestation minus afforestation) is estimated by the IPCC to range from 0.6 to 2.6 Gt C, i.e. between 10 to 45 percent of industrial CO2 sources. Current scientific consensus assumes the same range for the remainder of the 1980s, although preliminary assessments indicate that deforestation rates have accelerated in some regions (FAO, 1991). In this context, one should also note that deforestation rates can vary between indivi- dual years even in regions with the highest biota carbon fluxes and that have been intensively studied like Brazil. For instance, some estimates put the rate of deforestation in Brazil in 1987 at five (Meyers, 1989) to eight (WRI, 1990) million ha. Brazilian studies using satellite data indicate a deforestation rate of three million ha for the same year (IPOC, 1992). More recent results suggest that the rate is likely to have fallen even further to some two million ha in 1989 and 1.4 million ha in 1990 (IPCC, 1992). Therefore, it could be quite misleading to infer deforestation rates over extended time periods from point esti- mates of individual years. In view of the substantial uncertainties involved, a conservative approach to estimate biota carbon fluxes was adopted for this report. The reason for adopting a lower range of figures for biota CO2 emis- sions is primarily related to the fact that until now additional sinks (outside the oceans) could not be identified that would enable linking estimated high emission data with the capacity of known carbon sinks and the observational atmospheric concentration records. Although some estimates indicate additional carbon uptake by vegetation due to -19 - nitrogen and CO2 fertilization effects (perhaps of some 1 Gt C per year), these effects are still subject to scientific debate and are not quantified, especially at a regional level. The existence of large terres- trial carbon sinks would also tremendously complicate the problem of national carbon accounting due to the sheer insurmountable measure- ment problems. For instance, (yet unproven) estimates indicate that tropical forests - due to CO2 fertilization - could sequester a similar amount of C02 as tropical deforestation release. There certainly is no paucity in estimates of very high net carbon fluxes due to deforestation (e.g. Meyers, 1989; WRI, 1990), ranging up to 3.4 Gt C by the end of the 1980s. Howeveri it has to be emphasized that such high estimates have to date not found sufficient scientific con- sensus to be considered here.* Instead, a more conservative approach is adopted, focusing on lower range estimates of carbon release due to land-use changes. The values adopted (cf. Table 2.4 below) should not be interpreted as necessarily "realistic" estimates of deforestation car- bon releases, but rather as conservative values used in the absence of broader scientific consensus.** The resulting regional estimates sys- tematically tend to be on the lower range of the figures reported in Table 2.4 (particularly for India and Brazil). Due to the substantial uncertainties related to estimates of net carbon sequestering rates in forests of the northern hemisphere, a (conservative) convention was adopted to assume net biotic carbon fluxes to be zero in those cases where no indication of net deforestation rates were supported by national and international surveys. Carbon uptake due to nitrogen and C02 fertilization effects was also not considered here. With some 0.8 Gt C annually, the resulting estimated net biota C0 flux is at the low end of current scientific consensus within the IPCC process (IPCC, 1992; Houghton, 1991). However, the open architecture adopted for data representation and within the Parametric Framework ensures flexibility for incorporation of alternative data sets and for sen- sitivity analysis. Table 2.4 gives the regional breakdown of the esti- mates of current biota carbon emissions adopted here and contrasts these estimates with the upper and lower boundary extremes assembled * There Is wide consensus however, on the need of more In-depth and detailed stAudies of deforestation rates tad of the carbon characteristics of life vegetatlox and especially of soils. ** Particularly for Africa and Latlh America, higher values would have to be adopted (perhape twice the values given In Table 2.) to fall within the range given by a majority of literature sources. However, con- sensus of (a limited number of) experts does not necessarily Imply more accurate data. Table 2.4. Estimates of biota carbon fluxes in the early and late 1980s (in million tons carbon per year, rounded figures). Negative values indicate net carbon uptake by terrestrial biota. Late 1970s Late 1980s Per capita emssono arly 1980s (198-1987) (late 1980) (Values (Values ange adopted Blota adopted Industral slo sup 6* t c $10 sup 6$ t c here) t C/capita here) t c/capita Temperate sone: North Aerica +2sa - +38b -139* - +6 (0) -.51 - +0.02 (0) 5.28 Europ. (West & East) -8 - 0l -62e - ød (0 -.13 - 0 (0) 2.44 ussa +35 - 10 -14w - Cd (0) -.49- 0 (0) 3.83 Oceania +28 - -eb -r - 0 (0) -.17- 0 (0) 3.69 China + - 185b -10we - od (0) -.10- 0 (0) 0.56 Tropical mones. India +9m - 808 +5h - 18& (5) +.01 - +.18 (+.01) 0.21 Other Asia +100 - 10588 +3001 - 730d (320) +.39 - +.95 (+.41) 0.21 Africa +200 - 73 +1701 - 390< (170) +.35 - +.82 (+.35) 0.25 Brasi +175* - 8058 +140k - 800d (160) +.97 - +5.55 (+1.11) 0.41 Other LatAm +1760 - 4588 130" - 330 (140) +.46 - +1.17 (+.50) 0.84 WORLD +600 - 2600f +80 - - 2800 (800) +.16 - +.55 (+.16) 1.11 Eusinaa hn Japan and North Afric* & Middle East are negligible. a) Houghton ., 1987 f) PCC (Response Strategies), 1991 k) Alves, 1991 b) Houghto and Skole, 1990 mz#h Estinate 1) Houghton, 1991 c) Subak d ., 1991 g) OECL, 1991 m) Assumig same uancertainty range s in 1980. d) WRI, 1990 h) Pachauui, 1991 n) IPCC (Rasponse Strategies), 1991 e) IPOO (Rsponse Strtegs), 1991 I) Meyers, 1989 Gny closed forest LOW eståmat j) US AID, 1990, pp. 8-9 - 21- from various literature sources for the beginning and end of the 1980s. There is wide agreement that current biota carbon releases from the Northern hemisphere are quite small, if not negative. The range of esti- mates also indicate that biotic carbon releases or uptakes are small in comparison with industrial C02 sources (maximum 10 percent). There- fore, the uncertainty in the underlying data and our assumption of not considering biotic carbon sinks will not significantly influence the situa- tion of these regions vis a tis the remainder of the world due to their high levels of industrial C02 emissions in both absolute and per capita terms. Deforestation and land-use changes are currently concentrated in tropi- cal latitudes, but the corresponding net carbon release figures are affected by considerable uncertainties and debates in scientific and pol- icy circles. The range of estimates is large and has not narrowed com- pared to the figures estimated for the beginning of the 1980s. The uncertainties relate not only to the difficulty of estimating deforestation rates, but also to the paucity in reliable and detailed field measure- ments of the carbon content of biomass in tropical latitudes and espe- cially of the carbon release of disturbed tropical soils. The uncertain- ties in the latter are so large as to accommodate even the highest esti- mates of rates of deforestation with the lower range values given in Table 2.4, under low assumptions in biomass and soil carbon content and release rates. The policy relevance of these data uncertainties are obvious: high biota carbon emission estimates would increase the C02 emissions from most developing countries by between a factor of two to four. In the extreme case of Brasil*, the highest deforestation estimates would imply an increase of energy and industrial CO2 emissions by a factor of ten. In such case, the total per capita carbon emissions of Brasil would surpass even the highest per capita emission values of industrialized countries. The data uncertainties with regard to historical biota carbon emissions are somewhat smaller than for current emissions due to a good knowledge of historical energy and industry-related CO2 emissions and measurements of atmospheric concentration increases. The IPOC (1990) estimates for historical biota carbon releases indicate cumulative * Table n.4 .zoldes the prelimiuy (and mnbsequently evid) WRI estimate for Brasi of 1200 milion ton Cl 1987 wMh would Imp blots amisoas ofS.3 tons C per capta. - 22 - emissions of some 115 (d-35) Gt C over the 1850 to 1985 time horizon. This is in good agreement with the values adopted here for calculations with the Parametric Framework (of 120 Gt C over the same period, and 144 Gt C over the entire period covered by the Parametric Frame- work, i.e. 1800-1988). Compared to the current regional imbalances in biota carbon emissions, the estimated historical record appears more evenly distributed: perhaps 55 percent of historical biota carbon releases originate from the tropics, and some 45 percent from the tem- perate latitudes where significant land-use changes and deforestation (particularly in North America, Russia, and Oceania, cEf. Richards, 1990) took place in the 19th century. 2.2. Anthropogenic Methane Emissions After water vapor and carbon dioxide, methane is the next important atmospheric gas contributing to the greenhouse effect. Currently, the atmosphere contains some 4900 teragrams of methane (Tg of CH4) corresponding to an atmospheric concentration of 1720 ppbv (parts per billion by volume). Methane concentrations are rising at about one percent per year (equivalent to about 40 to 50 Tg or 14 to 17 ppbv per year). The recent measurements, however, indicate that the rate of increase in atmospheric concentrations has slowed down (Steele et al., 1992). It is estimated that a reduction by about 40 to 50 Tg (15 to 20 percent of annual emissions) would halt the rise in atmospheric concen- trations, assuming that methane destruction in the atmosphere by OH radicals would remain at present rates (IPCC, 1990). Large uncertainty ranges surround most of sources and sinks of methane so that the exact levels of global methane releases are unknown. It is estimated that the natural sources of methane emissions fall within the range of 100 to 300 Tg while anthropogenic sources are estimated at between 290 to 460 Tg annually. Thus, 60 to 70 percent of all global methane emissions are associated with human activities. Figure 2.3 illustrates the uncertainty ranges and the relative magni- tudes of different anthropogenic (and total natural) sources of methane emissions (Hogan et al., 1991). These ranges are in good agreement with those given by the IPCC (1990 and 1992) and are to be contrasted with the total global methane sink of between 400 to 600 Tg per year, resulting in 40 to 50 Tg of net annual atmospheric concentration increase. - 23 - so 100 MuIn Nuanm LAMM -4 Acont el1 0 25 0 75 100 Figure 2.3 Range of estimates of methane sources (in Teragrams). Source: Hogan et al., 1991. Numerous anthropogenic activities result in methane emissions, which in addition show wide variations in time and space. Furthermore, most sources are dispersed and occur outside the industry sector, which implies difficulties in collecting regular, reliable statistical sources and usually means the absence of direct field measurements. For the pur- poses of this report, it was however necessary to choose actual point estimates despite the inherently large uncertainties even in the emis- sions ranges. In general, we have assumed lower values given by the ranges in Figure 2.3 for our data set. Table 2.5 illustrates our assump- tions for five main anthropogenic sources of methane emissions disag- gregated into those arising in more developed regions (1 to 6, labeled as "North-) and those in developing regions (7 to 13, labeled as `South'). While fossil energy consumption is associated with the largest single category of emissions in the North, livestock and animal waste, and rice paddies are the largest two sources of methane emissions in the developing regions. Another difference along the "North-South' divide is that most of the landfill emissions occur in the more developed regions while biomass burning occurs mostly in the developing areas. Based on these point estimates, we have subsequently reconstructed the -24- Table 2.5. Estimates of anthropogenic methane emissions in 1988 (in Teragrams). World Total "North' 6South- (regions 1-6) (regions 7-13) Tg % Livestock and 43 62 105 35 animal waste Fossil energy use 45 35 80 27 Rice paddies 3 60 63 21 Landfills 24 12 36 12 Biomass burning 1 14 15 5 Total 116 183 299 100 a) Low end range estimate. regional historical emissions for the period 1950 to 1988 based on activity variables (like regional rice production, size of livestock, or fos- sil fuel production statistics) since direct observations (emission meas- urements) are not available. Longer time-series were not required due to the limited residence time of methane in the atmosphere of about ten years. The atmospheric residence time can be changed to another value by the use of the Parametric Framework. The time-series of methane emissions in the data set of the Parametric Framework give annual releases of anthropogenic sources for 13 world regions. They were aggregated from individual estimates of five different anthropo- genic methane sources (included in the Parametric Framework only as the aggregate sum). The first and largest source given in Table 2.5 is associated with agri- cultural livestock and their wastes. About three-quarters are believed to be caused by enteric fermentation in ruminant animals, including all cattle, sheep, etc., and the rest by the decomposition of animal waste. Our estimate of global emissions from all domestic animals (cf. data appendix) is about 105 Tg of methane, and thus in the middle of the ranges given in the literature. Emissions depend on animal population as well as on the size of the individual animals, the amount and type of food. Our estimates are based on the domestic animal population sizes in the 13 world regions. According to this method, the emissions - 25 - increased almost two-fold since 1950. The next largest category of methane emissions is due to the produc- tion, transport and distribution of fossil energy with the main sources being coal mining, and oil and gas production. Most of the methane released fr-m coal production is due to underground coal mining (venti- lation of methane present in the coal seams and in the surrounding rock strata). Methane leakage from pipelines and distribution grids, and venting and leakage from oil and gas production wells are also impor- tant. Our estimates of fossil fuel related methane emissions again fall in the mid-range presented in Figure 2.3 and are a result of differing certainty in the underlying time-series. While the production of fossil energy sources is known with a rather high degree of precision, the actual methane emission factors are only indicative. For example, natural gas leakages from pipelines and distribution networks are believed to range from less than half a percent in some industrialized countries all the way to more than six percent for the Soviet Union.* Thus, the overall fossil energy methane emissions are not well known. However, they do represent the single fastest growing category of anthropogenic emissions leading to a more than four-fold increase since 1950. Rice paddies are another rapidly growing source of methane emissions. They depend on a number of factors that vary regionally and annually including fertilization, water and crop management, growing period and paddy characteristics among others. The majority of emissions occur under wet rice cultivations that represent almost 85 percent of the worldwide cultivation area. Our estimates of present and historical emissions are based on rice production data for the 13 world regions. The resulting emissions are in the mid-range given in the literature (e.g. IPCC, 1990; Hogan et al., 1991). However, the uncertainty associated with the range and its span is the largest of all anthropogenic sources of methane and extend from less than 50 to 170 Tg. The difficulty is that almost 90 percent of the cultivated area is in Asia and 60 percent of that in China and India where no detailed data are available, so that at best only rough estimates can be made (IPCC, 1990). Estimates indi- cate that the emissions increased from about 70 Tg in the 1950s to * However, give the large throughput through the gas pipeline grid of the USSR, such high leakage AMe would Imply fequent methane explouoas. To date, however, so such leakage explosons have been report- ed. The only major recent pipeline accidet was due to leakage of Iqulled petrolem gas (LPG) and not a- tural gas (methane). - 28 - almost 100 Tg by the early 1980s to decrease by almost 40 percent dur- ing the last decade. Another reversal is however likely with further population growth and an increased demand for rice. To an extent this could be offset by better cultivation methods that lead to lower specific emissions. Altogether, rice production has doubled since the 1940s and it can be expected that the methane emissions have increased propor- tionately. In contrast to methane emissions from rice cultivation, most of the emissions from landfills originate in the more developed regions which hold a two-thirds share of the global total. These emissions are caused by the anaerobic decay of organic wastes in landfills and are a function of municipal waste generation and disposal practices, landfilling rates, types of waste material and their average hydrocarbon content, and conversion and outgasing rates of methane. Another important deter- minant is whether the deposition sites are equipped with effective liners and other measures to reduce emissions of methane and other air toxic gases. However, in many industrialized countries methane recovery from landfills is becoming an additional source of energy supply, result- ing in reduced CH4 emissions to the atmosphere. Due to the difficulties in estimating the relative magnitudes of these determining factors, landfill methane sources have the third largest uncertainty range of between 20 to 70 Tg (IPCC, 190; see also Figure 2.3) after rice paddies and biomass burning. Our estimates are exactly in the middle of the ranges given in the literature. The extent of land clearing and biomass burning worldwide is not well understood. Major uncertainties include the amount vf biomass burnt each year in different regions by type of vegetation, fraction of wood or biomass removed and used for other purposes from the cleared areas, the kind of burning, etc. Deforestation by itself is an important but probably smaller source of methane compared to other anthropogenic sources such as agricultural activities (e.g. rice production and agricul- tural wastes). Despite the broad range of estimates given in the litera- ture, one thing is clear, namely, that the emissions from deforestation and biomass burning have increased substantially since the beginning of the Industrial Revolution and probably even since the beginning of land cultivation. The ratio between the largest and lowest estimates in the literature is greater than five and thereby exceeds those of all other anthropogenic methane sources. Currently the largest source of biomass burning that results in methane emissions is believed to be - 27 - caused by deforestation in tropical and sub-tropical regions of the southern hemisphere. Our estimates reflect this with 90 percent of the emissions originating from the developing regions of the South. The relative magnitude of our estimates is, however, in the lower range with about 30 Tg. This is also consistent with our conservative low estimate of CO2 emissions from biomass burning because both time series are based on the same estimates of worldwide deforestation rates. In summarizing the above discussion on methane emissions, it must again be emphasized how much larger the uncertainties associated with such estimates are, especially when compared to fossil fuel emissions. It is also important to recognize that methane emissions are extremely inhomogeneous, including both industrial, agricultural, and biotic sources. Industrial emissions (from fossil fuel production and landfills in industrialised countries), are in principle controllable by appropriate technologies and economic policy instruments. Contrarily, agricultural and biotic methane sources are extremely dispersed, frequently occur- ring outside the formal economy (like subsistence rice farming), and are associated with particularly large uncertainties regarding specific emis- sion factors per unit of anthropogenic activity. Consequently, we sug- gest that in future studies these two methane emission categories be treated separately. 2.3. CO2 and CH4 After discussing individual GHG emissions by gas and category, we aggregate all data to estimate the cumulative historical and current annual total emissions of those GHGs which are the largest contribu- tors to potential climate change. For this purpose, a methane equivalent factor of 21 (on mass basis) compared to CO2 is used. By convention, the total C02-equivalent emissions are expressed by the equivalent mass* of carbon only. Table 2.6 (cf. Table 2.3 above for industrial CO2 emissions) presents regionalised total GHG emissions per unit land area, population and unit of economic output. Compared to the case when only industrial CO2 sources are, considered, the regional disparities are somewhat reduced, especially from a "North--South" perspective. However, regional disparities still remain extremely wide. For instance, per * To cvWt to C02 mut* by 6. - 28- capita differences in GHG emissions between regions still differ by a factor of 12, and per unit of GDP (based on purchasing power parities) by a factor of five. The inclusion of biota carbon and methane emissions significantly affects the relative position of all developing countries with the excep- tion of region 10 (North Africa and Middle East) vis a vi the "North". However, the impact is far from uniform among developing, or even among developed countries. Four groups of countries can be dis- tinguished. In the first one, the inclusion of biota and methane emis- sions increases regional GHG emissions by 20 percent over industrial CO2 emissions only. This situation applies to all regions of the "North with the exception of region 6 (Oceania). In the second group of countries/regions, the total GHG emissions are about 50 percent higher, i.e. in regions 6 and 7 (Oceania and China); whereas in regions 8 and 13 (India and Rest of Latin America), the total GHG emissions are between 150 percent and 250 percent higher due to either extensive deforestation or high agricultural methane emissions. Regions 9 and 11 (Other Asia and Other Africa) have total GHG emissions of around 350 percent over their industrial CO2 releases. The largest shift occurs in Brazil where total GHGs are a factor five higher than industrial CO2 emissions alone. Consequently, all specific emission factors deteriorate when one moves from industrial CO2 to total CO2 and CH4 emissions. The required reductions under various allocation scenarios will also generally be higher with increasing GHG equivalent-carbon emissions, if biota and agricultural emission sources are included in addition to energy and industry. Figure 2.4 (cf. Figure 2.2 above for energy and industry CO2 emissions) summarizes the regional breakdown of greenhouse gas emissions (anthropogenic CO2 and CH4). The top of Figure 2.4 gives current emissions, and the bottom shows the contribution of each region to atmospheric concentration increases. Compared to Figure 2.2, the "North-Souths divide in current emissions, and especially in contribu- tions to atmospheric concentration increases, is somewhat smaller but still pronounced. Industrialized countries account for 58 percent of current GHG (total CO2 and CH) emissions and for 67 percent of the increase in atmospheric concentrations since the onset of the Industrial Revolution. Table 2.6. 1988 greenhouse gas (C02 and CE4) emissions: comparison of absolute and relative values (in gigatons and tons carbon-equivalent). Per capita population Per unit GDP (1068 $) Per land 1988 emissions area total adult market exch. PPP Gt Ce t C,/km t C/cap t C/cap t Ce/1000$ t C/1000$ 1 OECD NA 1.84 85 6.06 7.81 0.31 0.84 2 OEOD EU 1.00 232 2.62 3.39 0.18 0.21 8 Eastern EU 0.42 457 3.65 4.55 1.70 0.75 4 USSR 1.28 56 4.50 6.12 2.19 0.75 5 Japan 0.29 768 2.37 3.07 0.10 0.18 8 Oceania 0.11 13 5.58 7.81 0.41 0.48 7 China 0.92 95 0.85 1.25 2.76 0.39 - 8 India 0.41. 125 0.51 0.89 1.54 0.49 9 Other Asia 0.58 71 0.75 1.33 0.81 0.37 10 NAME* 0.30 23 0.90 1.81 0.55 0.40 11 Other Africa 0.42 16 0.87 1.68 1.76 0.94 12 Brazil 0.30 35 2.09 3.50 0.85 0.48 13 Other LatAm 0.47 39 1.69 2.94 0.88 0.45 SNorwth (1-6) 4.73 86 3.97 5.18 0.82 0.35 *South* (7-13) 3.39 43 0.87 1.58 1.14 0.45 World 8.12 61 1.60 2.54 0.45 0.39 Factor Difference 5.7 59.1 11.9 8.8 27.6 5.2 smallest-highest *North Africa and Middle East -30- USSR (15T%) Norh Amica (202%) DAM Sape 1I MDCs: 58.8% LDCS. 41.7% est of Latin Amerie (S%) Watern Swope (2.3%) Brasil I%) Res of Afdes (I%) N. Africa & Mid East (S%) Japan (36%) Ret of Asia 17.1%l CWna (11.3%) Australia & KL Zealand i)4% ndia (51%) USSi I1.4%) Australla & I ZelId (1.9%) N Jap123%l Easten ESsepe (4.7% telt fLatin Ameria (6M) MDC 6.9% LDC: 33.1% Istfafria152% K Africa & Mi. East i.%) Rest of Asia (M2% daK CdaWestem F.wepb (14%) Figure 2.4 Shares (in percent) of different regions in anthropogenic GHG (COs and CH4) emissions in 1988 (top), and in contribution to historical concentration increases (1800 to 1988 for C02, and 1950 to 1988 for CH (bottom). - 31 - Including deforestation CO2 and anthropogenic CH4 emissions 1kg CH4 -21 kg COg, different residence times are also considered 68 All other All other C02+CH4 CO2+CH4 Industrial Industrial Co2 C02 4 Cumulative 1988 1800-1988 3 2 World 1988 1r LyrL I Wo Ie 1 M 17 0 North OECD Eastem USSR Japan Oceania China India Other NAME* Other Brazil Other Latin America Europe Europe Asia Africa America 'North Africa and Mddle East Figure 2.5 Current (1988) and cumulative (1800-1988) per capita GHG emissions for 13 world regions (in tons carbon equivalent per cap- ita and per person-year). Range corresponds to industrial CO2 emis- sions only, and total C02 and CH4 emissions, respectively. Figure 2.5 shows current GHG emissions per capita and historical (1800-1988) cumulative emissions per person-year lived over this time period. Again industrial CO2 and total C02 and CH4 emissions are separated. Compared to Figure 2.4, "North-South" disparities are more pronounced when expressed on a per capita basis. However, it is also interesting to note that generally the patterns of differences between current and historical contributions on a per capita basis among countries resemble each other. Thus, the countries with current higher per capita emissions have also emitted more* per person in the past. And evidently, regions with low current emissions also have low * Differences betweu curmt and historical per capita emisone are more pronounced In Eastera Earope, the former USSR, and Japa. There increases in anthropogeak ORG emisieons ae a much more recent phenomenon compared to early industrialislag Wetern Europe or North America. -o2- historical emissions both on an absolute and on a per capita basis. The implications of such disparities for different GHG reduction and alloca- tion scenarios will be discussed in the following chapter. 8. Greenhouse Gases Reduction Criteria The Framework Convention on Climate Change (Resolution INC/1992/1) states in Article 2 as an objective of the Convention: "... to achieve... stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropo- genic interference with the climate system. Such a level should be achieved within a time frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner." This objective clearly implies that a reduction in the growth of global greenhouse gas emissions is required because stabilization of concentra- tions is the overall goal. In conjunction with the findings of the IPCC, such an objective furthermore implies that also absolute emission levels have to be reduced since they exceed the known terrestrial sinks. "... the parties should protect the climate for the benefit of present and future generations of humankind, on the basis of equity and in accordance with their common but differentiated responsibilities and respective capabilities. Accordingly, the developed country Parties should take the lead in combating climate change and the adverse effects thereof." (Article 3.1 INC, 1992). Furthermore, Annex I to the Framework Convention notes: "... that the largest share of historical and current global emissions of greenhouse gases has originated in developed countries, that per capita emissions in developing countries are still relatively low and that the share of global emissions originating in developing coun- tries will grow to meet their social and development needs, ..." These passages from the Convention clearly indicate the dilemmas involved in simultaneously stabilizing GHG concentrations while allow- ing for economic development. Perhaps for that reason the Convention abstains from giving a single criterion which could reconcile such - 33 - diverging objectives. In this report, we consider four different reduc- tion criteria and investigate their implications for the 13 different world regions. All four are incorporated in the Parametric Framework software and thus enable the user to investigate the consequences of changing assumptions such as altering the underlying data (e.g., of his- torical emissions, greenhouse gas sources to be considered, -etc.), changes in the reference year or peric for assessment of the reduction criteria, changes in the target year by which the reduction is to be achieved, and alteration of other accompanying parameters used in GHG accounting. The four criteria considered here are: equal per capita emission rights, across-the-board percentage cuts, cutbacks proportional to past contri- butions to atmospheric concentration increase, and equal per capita emission rights equivalent to natural carbon sinks. The first criterion is conceptually the simplest and in fact was explicitly suggested in earlier drafts of the Framework Convention stating that emissions should converge at a common per capita level (INC, 1991). In the case of the calculations here, each of the 13 regions is allowed to emit a fixed amount of greenhouse gases per capita. Under global emis- sion stabilization or reduction, this criterion requires that the more industrialized regions (1-6) make severe emission cuts, while populous developing regions are, in most cases, permitted to increase their abso- lute emissions considerably. This criterion has the additional advan- tage that it is invariant for both global emissions increase and decrease: Some of the industrialized regions need to reduce their per capita emis- sions even if global emissions are allowed to increase. The other three criteria are asymmetrical in the sense that they would allow large emitters to increase their emissions more than the developing relions in the case of global increase. Across-the-board percentage cuts or the "grandfathering criterion is more similar to the Montreal and London Protocols on CFCs phase-out and the European Convention on Transboundary Air Pollution in that it specifies percentage decrease with respect to some representative reference year or period. A particular instance of such a criterion was given in an earlier text of the Framework Convention given as "Alter- native A (ii)w specifying a stabilization of "[Net] emissions of [energy related]/[anthropogenic] greenhouse gases [other than those controlled by the Montreal Protocol] at [in general] 1990 levels by the year 2000" (INC, 1991). In general, the criterion would require a certain .34- percentage cut in the future, say in the year 2000, with respect to a given historical level. Choice of an earlier reference year favors regions with slowly growing emissions or those regions that achieved higher emission levels earlier. Under the global emission increase variant, this criterion would favor high emitters by allowing proportional increases with respect to the reference levels. The criterion of cutbacks proportional to past contributions to anthro- pogenic concentration increase reflects equity and common but differentiated responsibility considerations specified in the principles of the Framework Convention (INC, 1992). Another way of understand- ing this criterion is to consider emissions and the resulting anthropo- genic increase of greenhouse gases concentration as a natural resource available to humanity ,to be shared throughout the world by both current, past and future generations. Those regions and countries that have. emitted overproportionally have accumulated a "natural debt" (Smith, 1990). Thus, the criterion could represent possible compensa- tion for "natural debt" since the largest part of current anthropogenic concentration increase originates from the more developed regions. It clearly favors rapidly developing regions that have not made much of an historical contribution relative to current emission rates. It should also be mentioned that the criterion prescribes reductions for all regions though greater ones for those that bear larger historical responsibility. Thus, it does not allow for emission increase in the developing regions as does the equal-per-capita criterion (as long as global GHG reduc- tions are not too drastic). Under the global emission increase variant, this criterion would overproportionally favor high emitters and is in our opinion inappropriate in those cases. This criterion is also the most complex of the four since it involves cumulative historical greenhouse emissions to be analyzed by accounting for the different residence times of carbon dioxide and methane in the atmosphere and the different glo- bal warming potentials of these two gases. In the other three criteria, the anthropogenic contribution to concentration increase is not expli- citly considered. Instead, annual emissions in the reference period serve as the sole determining factor for future emissions in the target year. The last of the four criteria is perhaps the most complex at least on the conceptual level. A fraction of anthropogenic greenhouse gases is "removed" from the atmosphere annually by natural sinks. The basic idea (e.g., Argawal and Narain, 1991) is to first allocate these natural sinks in some manner and reduce emissions beyond those levels. In theory, this could be done by accounting for regional emissions and - 35 - subtracting endogenous sinks such as absorptions of carbon dioxide by biota and coastal waters. In addition, each region would receive some fair share of other common sinks such as oceanic uptake of carbon diox- ide or atmospheric destruction of methane. The resulting net emissions balance could then be reduced either by equal percentage or according to historical contribution or by some other method. The real problem is that the exact nature and distribution of natural sinks is even less well known than the structure of anthropogenic emissions. In any case, roughly one half of the carbon dioxide emissions are removed from the atmosphere annually. Total current carbon dioxide emissions are about 6.4 Gt C so that the magnitude of the global natural sink would be about 3 Gt C annually. According to the criterion, this number is allocated on an equal-per-capita basis among the 13 world regions. In the Parametric Framework, the magnitude of the sink can be changed by the user. Emissions in the reference year are reduced to the allo- catcd levels that correspond to the sink specified for the reference year. If frture emissions are assumed not to exceed the specified current sink, of say 3 Gt C, then this criterion is identical to convergence to equal per capita emissions. The difference is that in the equal per capita emissions case the sum total global emissions are not specified explicitly but are the result, while in the case of the allocation of the sink, the global sum total is specified and the required level of per capita emis- sions is the result. Thus, the two criteria can be used in conjunction. Strictly speaking, the hypothetical allocation of -a "natural sink" is a misnomer and also technically incorrect since sinks are a function of the emission levels. Lower emissions are associated with lower sinks, while it is believed (or at least hoped) that higher emission levels would also lead to proportionally higher natural sinks. 8.1. Reduction Scenarlos Based on Four Criteria In the following sections, we analyze the quantitative implications of different GHG allocation criteria for a common global reduction target. For reasons of comparability between different scenarios (criteria and type of GHG considered), all calculations are based on the same target value of emissions to be reached. We have adopted a target value of 4 Gt C (or C-equivalent) to be reached by the year 2050. This drastic reduction target value was chosen for illustrative purposes in order to elucidate more clearly the distributional consequences of different allo- cation criteria. The target value of 4 Gt C by 2050 represents a 50 per- cent cut in current anthropogenic GHG emissions and is somewhere -38- between the Accelerated Policies and the Alternative Accelerated Poll- cies Scenarios of the 1990 report of the IPCC. The only exception is the scenario based on the natural sink allocation criterion, where we have assumed a target value of 3 Gt C plus an additional sink of 1.5 Gt C-equivalent for methane emissions. We have only used one target year throughout the analysis, as the criteria examined are static (between two reference years only) and do not contain any element of determining different dynamic paths for the achievement of a given emission reduction target. Reference and target year and target values can be chosen freely with the Parametric Framework. 8.2. Equal Emission Rights Per Head This scenario assumes that per capita GHG emissions converge to a common value of 420 kg C (or C-equivalent) per capita, i.e. 4 Gt C divided by 9.5 billion people in 2050 (based on a World Bank Projec- tion, Zachariah and Vu, 1988). The results of the scenario are given in Table 3.1. The most important characteristic of this scenario is that it is the only one in which the developing regions of the "South" are in fact allowed to increase their absolute emission levels. In few cases even per capita increases can occur, i.e. where present per capita emissions are lower than the target value, such as in regions 8, 9, 10 and 11. A surprising finding of the analysis is that if CO2 and CH4 emissions from all sources are considered together then even the region with the lowest current per capita emissions is still above the level consistent with a target value of 420 kg C-equivalent per capita by 2050. This implies reduc- tions in per capita emissions for all regions if CO2 and CH4 are con- sidered together, though absolute emission levels could rise in regions 8 to 11. The other extreme in such a scenario is represented by the more developed regions of the "North" that have to achieve drastic reduc- tions in both per capita and absolute levels of emissions. They are higher than in any of the other three scenarios considered here.* The magnitude of the drastic reductions required is best illustrated with the case of region 1 (North America) which would have to reduce current * With the eceptio of a case la which natura GOG lab e Wallocated o a per capita basi aud the target value equals the aatural OG alake, ia which case the two sceamilo are identical. Table 3.1. Overview of emission reduction scenario (to 4 Gt C or C-equivalent) by 2050. Criterion used: Equal per capita emissions in target year. Comparison of current and target emissions and required reductions, in Gt C or Gt C-equivalent. Reduction rates, %/yr Base year value (1986) Target year for controlaing value Industrial CO2 Total CO2 CO2 + CH4 Industrial CO2 CO2 CO2 + CR4 Gt C Gt C Gt C, Gt C (Ce) only only 1 OECD NA 1.43 1.48 1.64 0.13 -3.6 -3.8 -4.0 2 OECD EU 0.85 0.85 1.00 0.16 -2.7 -2.7 -2.9 8 Eastern EU 0.36 0.36 0.42 0.06 -2.9 -2.9 --.1 4 USSR 1.09 1.09 1.28 0.15 -8.2 -3.2 -44 & Japan 0.27 0.27 0.29 0.05 -2.7 -2.7 -2.8 ce 6 Oceania 0.07 0.07 0.11 0.01 -3.1 -3.1 -3.8 7 China 0.61 .0.61 0.92 0.69 +0.2 +0.2 -0.5 8 India 0.17 0.17 0.41 0.64 +2.2 +2.2 +0.7 9 Other Asia 0.16 0.47 0.58 0.70 +2.4 +0.6 +0.3 10 NAME* 0.24 0.24 0.30 0.37 +0.7 +0.7 +0.3 11 Other Africa 0.12 0.27 0.42 0.70 +2.9 +1.5 +0.8 12 Brazil 0.06 0.22 0.30 0.11 +1.0 -1.1 -1.6 13 Other LatAm 0.24 0.36 0.47 0.24 +0.0 -0.7 -1.1 "North (1-0) 4.07 4.07 4.73 0.56 -3.2 -3.3 -3.4 "Southr (7-13) 1.60 2.35 3.39 S.44 +1.2 +0.6 ±0.0 World 5.86 6.41 8.12 4.00 -0.6 -0.8 --1.1 *North Arca and Middle EAt -38- GHG (CO2 and CB4) emissions to a meager one-ffteenth (seven per- cent) of current levels, implying a reduction rate of four percent annu- ally until the year 2050. For other developed regions, the reductions required are smaller, but by no means less dramatic: absolute emissions have to be reduced to 14 percent of current levels by the year 2050, implying reduction rates of about three percent annually (between 2.8 to 3.8 percent/year). Such high reduction rates (to be sustained over 70 years) are without precedent in history. Only over very limited periods of time were similar carbon reduction rates achieved. For instance, France has reduced its energy related carbon emissions by some 2.3 percent/year since 1973 due to both energy efficiency improvements and the vigorous introduction of nuclear energy. If the scenario is based only on fossil fuel and induetrial sources of C02 then all of the developing regions (7 to 13) can increase their absolute emission levels, while the reduction levels of the industrialised regions are slightly lower than is the case when considering all GHGs from all sources. If C02 from biota sources are added to the considerations then Latin America (regions 12 and 13) has to reduce its absolute C02 emissions. When methane emissions are also considered, all of the developing regions are allowed smaller increases, with Latin America (regions 12 and 13) requiring larger reductions (compared to the "CO2 only" scenario), and region 7 (China) shifts from a position of absolute emission increase to decrease. In another sensitivity analysis, the equivalence factor between the radi- ative forcing of C02 and CH4 was changed from 21 to 58 on a mass basis (Table 3.2). This implies that methane emissions are weighted more heavily against C02 in contributing to global warming. This sen- sitivity analysis results in net absolute emission reductions for all regions except region 11 (other Africa), indicating how important this factor is in this case. In this context, it should be noted that changing the global warming potential of methane might turn out to be the most important variation due to the large uncertainty concerning, in particu- lar, the indirect radiative forcing of CH4 compared to C02 (see e.g. the IPOC 1992 supplement). Table 3.2. Sensitivity analysis for criterion: Equal per capita emissions in target year of .42 ton C-equivalent (CO2 and CH4) per capita in 2050. Sensitivity: Methane equivalence factor of 58 vs 21, in Gt C-equivalent. %/year reduction required to 1988 CO2 + CE4 1988 CO2 + CH4 reach 420 kg C./capita by 2050 emissions emissions Methane GWP=21 Methane GWP=58 absolute emissions per capita emissions CE4 CH4 CH4 Ca4 Gt Ce t C,/capita Gt Co t C./capita GWP=21 GWP=58 GWP=21 GWP=58 1 OECD NA 1.4 6.08 2.01 7.42 -4.0 -4.3 -4.2 -4.5 2 OECD EU 1.00 2.62 1.26 8.31 -2.0 -3.3 -2.9 -3.3 3 Eastern EU 0.42 3.85 0.51 4.51 -3.1 -3.4 -3.4 -3.8 4 USSR 1.28 4.50 1.61 5.68 -8.4 -3.8 -3.8 -4.1 5 Japan 0.29 2.87 0.33 2.66 -2.8 -3.0 -2.8 -2.9 6 Oceania 0.11 5.58 0.18 8.92 -3.8 -4.6 -4.1 -4.8 7 China 0.92 0.85 1.64 1.35 -0.5 -1.4 -1.1 -1.9 8 India 0.41 0.51 0.83 1.02 +0.7 -0.4 -0.3 -1.4 9 Other Asia 0.58 0.75 0.76 0.99 +0.3 -0.1 -0.9 -1.4 10 NAME* 0.30 0.00 0.39 1.19 +0.3 -0.1 -1.2 -1.7 11 Other Africa 0.42 0.87 0.66 1.39 +0.8 +0.1 -1.2 -1.9 12 Brail 0.30 2.09 0.44 3.07 -1.6 -2.2 -2.6 -3.2 18 Other LatAm 0.47 1.69 0.68 2.42 -1.1 -1.7 -2.2 -2.8 &North' (1-6) 4.73 3.97 5.90 4.95 -3.4 -3.7 -3.8 -3.9 'Souths (7-13) 3.39 0.87 5.24 1.34 ±0.0 -0.7 -1.2 -1.9 World 8.12 1.60 11.14 2.19 -1.1 -1.8 -2.1 i-2.6 *North Africa and Middle ast -40 - 8.3. Across-the-Board Percentage Cuts (Ograndfathering) This scenario assumes that all regions have to cut their current abso- lute emission levels by a certain percentage in the target year with respect to the reference year. Here, we illustrate the results by apply- ing this scenario to our data set again using the standard set of assumptions (target year 2050, reference year 1988, and target total global emissions of 4 Gt C or C-equivalent). Depending on which greenhouse gases are considered, this results in a homogeneous reduc- tion of 1988 absolute emission levels throughout the world by 51 per- cent (CO), 38 percent (all C02), and 29 percent (energy and industry C02), respectively. Table 3.3 summarizes the results of this scenario on a per capita basis. The reason for showing a per capita representation is that while in absolute emission terms the rank order between regions is preserved, regional per capita disparities become larger due to differentiated rates of future population growth. For example, when all GHGs are con- sidered, reaching a target value of 4 Gt C-equivalent implies a reduc- tion of absolute emissions by 51 percent or at a rate of 2.1 percent per year (1988-2050 average). However, per capita emissions have to be reduced much more drastically in the "Southr (regions 7-13) than in the "North". Modest population growth in the "North" results in aver- age per capita emission reduction rates of 1.3 percent per year (ranging between 1.1 to 1.5 percent/year) only. Thus, whereas per capita emis- sion reduction in the regions of the "Norths are all below 1.5 percent per year, the average reduction in the "South is 2.3 percent per year with a range between 1.8 to 3.1 percent/year. As a result, present per capita emission disparities widen. Currently, the "North" emits 5.6 times as much GHG per capita than the "South", and by the year 2050 this ratio increases in this scenario to 8.9. Clearly "grandfathering implies placing a larger burden on the future generations of the "South' for global emission reductions. However, absolute per capita emission reductions in the "North* are larger: -3.55 tons/capita com- pared to -0.45 tons per capita in the "South" (cf. Tables A.3 and A.4 in the Appendix). When considering which GHGs should be included under a "grandfa- thering' criterion, then a counterintuitive situation arises. Developing countries would have an interest in accounting for biotic carbon and methane emissions, in addition to industrial C02 because their respec- tive current emissions would be higher, leading to a higher "emission Table 3.3. Overview of emission reduction scenario (to 4 Gt C or C-equivalent) by 2050. Criterion used: Across-the-board percentage cuts from 1988 - absolute emission levels. Comparison of current and target per capita emissions and required reductions, in tons C or C-equivalent per capita. Base year value (1988) Target year value (2050) %/yr reduction rates Industr. COs Total 002 CO + CH4 Industr. CO2 Total C02 0 + CH4 lIdustr. Total t C/cap t C/cap t C/cap t C/cap t C/cap t C*/cap CO, CO, CO, + CH4 1 OCD NA 5.28 5.28 6.06 3.26 2.68 2.61 -0.6 -1.0 -1.4 2 0ECD EU 2.22 2.22 2.62 1.61 1.42 1.32 -0.5 -0.7 -1.1 3 Eastern EU 3.17 3.17 S.65 1.91 1.69 1.54 -0.8 -1.0 -1.4 4 USSR 3.83 3.83 4.50 2.11 1.66 1.73 -1.0 -1.2 -1.5 5 Japan 2.20 2.20 2.37 1.51 1.33 1.13 -0.6 -0.8 -1.2 8 Oceania 3.69 3.69 5.56 2.10 1.66 2.22 -0.9 -1.1 -1.5 7 China 0.56 0.56 0.85 0.26 0.23 0.28 -1.2 -1.4 -1.8 8 India 0.21 0.22 0.51 0.08 0.07 0.13 -1.6 -1.8 -2.1 9 Other Asia 0.21 0.61 0.75 0.07 0.18 0.17 -1.8 -2.0 -2.4 10 NAM* 0.73 0.73 0.90 0.19 0.17 0.17 -2.1 -2.3 -2.7 11 Other Africa 0.25 0.57 0.87 0.05 0.10 0.12 -2.6 -2.7 -3.1 12 Brasil 0.41 1.53 2.09 0.16 0.51 0.55 -1.6 -1.8 -2.1 13 Other LatAM 0.64 1.27 1.68 0.30 0.40 0.42 -1.7 -1.9 -2.2 cNortho (1-4) 3.41 3.41 3.97 2.16 1.91 1.75 -0.7 -0.9 -1.3 ASouths (7-13) 0.41 0.00 0.87 0.14 0.18 0.20 -1.8 -1.9 -2.3 World 1.11 1.26 1.60 0.42 0.42 0.42 -1.6 -1.8 -2.1 *North Africa and Middle East Table 3.4. Sensitivity analysis for criterion: Across-the-board percentage cuts to 4 Gt C by 2050 from absolute values of base year (industrial CO2 emissions only). Sensitivity: Variation of base year, in Gt C. 1988 Equal % Cuts from Base Year Levels to 4 t C by 2050 emissions Gt C 1988 base 1985 base 1980 base 1975 base 1970 base 1 OECD NA 1.48 1.01 1.00 1.09 1.16 1.29 2 OECD EU 0.85 0.80 0.68 0.76 0.80 0.89 8 Eastern EU 0.86 0.25 0.27 0.27 0.28 0.24 4 USSR 1.09 0.77 0.75 0.71 0.72 0.8s 5 Japan 0.27 0.19 0.19 0.20 0.21 0.21 6 Oceania 0.07 0.05 0.05 0.04 0.05 0.04 W 7 China 0.61 0.43 0.41 0.82 0.28 0.22 8 India 0.17 0.12 0.11 0.08 0.06 0.08 9 Other Asia 0.18 0.11 0.11 .0.09 0.08 0.07 10 NAME* 0.24 0.17 0.17 0.14 0.12 0.10 11 Other Africa 0.12 0.09 0.09 0.08 0.07 0.08 12 Brazil 0.08 0.04 0.04 0.04 0.04 0.03 13 Other LatAm 0.24 0.17 0.16 0.17 0.15 0.15 "North* (1-6) 4.07 2.87 2.93 3.07 8.19 3.38 OSouth* (T-13) 1.60 L13 1.08 .0.93 0.81 0.87 World 5.6 4.00 4.00 4.00 4.00 4.00 2050 emission as % of base year (70.6%) (T6.0%) (19.1%) (90.8%) (102.6%) *North Africa and Middle East Table 3.5. Sensitivity analysis for criterion: Across-the-board percentage cuts to 4 Gt C-equivalent from absolute values of base year (all C02 and CI14 emissions). Sensitivity: Variation of base year, in Gt C-equivalent. 1988 Equal % Cuts from Base Year Levels to 4 Gt Co by 2050 emissions Gt Co 1988 base 1985 base 1980 base 1975 base 1970 base 1 OECD NA 1.64 0.81 0.76 0.78 0.78 0.83 2 OECD EU 1.00 0.49 0.51 0.53 0.52 0.55 3 Eastern EU 0.42 0.21 0.20 0.19 0.18 0.17 4 USSR 1.28 0.63 0.58 0.52 0.50 0.47 5 Japan 0.29 0.14 0.14 0.13 0.13 0.12 6 Oceania 0.11 0.05 0.05 0.06 0.09 0.10 , 7 China 0.92 0.45 0.41 0.36 0.34 0.31 8 India 0.41 0.20 0.19 0.17 0.19 0.23 9 Other Asia 0.58 0.28 0.39 0.39 0.35 0.30 10 NAME* 0.30 0.15 0.14 0.11 0.10 0.09 11 Other Africa 0.42 0.20 0.24 0.30 0.23 0.22 12 Brazil 0.30 0.15 0.14 0.13 0.20 0.20 13 Other LatAm 0.47 0.23 0.26 0.33 0.40 0.40 "North* (1-6) 4.73 2.33 2.24 2.20 2.20 2.24 "South* (7-13) 3.39 1.67 1.76 1.80 1.80 1.76 World 8.12 4.00 4.00 4.00 4.00 4.00 *North Africa and Middle East -44- allowance' in the target year. For instance, when only industrial CO2 emissions are considered then the "North" would have to reduce to 2.87 Gt C, whereas the "South" would have to reduce by the same percen- tage from its currently low emission levels to 1.13 Gt C by 2050. When all C02 and CH4 emissions are considered, the resulting regional alloca- tion (again for a global target of 4 Gt C-equivalent) would be 2.33 Gt (down 19 percent from the industrial CO2 case) versus 1.87 Gt C- equivalent (48 percent higher than in the industrial C02 case) in the "North" and "South", respectively. This scenario is also the most sensitive to the choice of the reference year from which equal percentage cuts are being calculated. Conse- quently, we varied the reference year between 1988 and 1970. Here we discuss only the results of the calculation for energy and industrial C02 emissions (Table 3.4) because it is the most sensitive to changes in the reference year. Table 3.5 however gives equivalent results when consid- ering all GHG emissions. A general conclusion of this sensitivity analysis confirms the fact that those regions and countries whose emis- sions increased most rapidly during the last decades have to bear ever higher reductions the further the reference year recedes into the past. Conversely, those regions and countries that experienced stable emis- sions or even emission reductions benefit the most and are in some cases even allowed marginal increases in absolute emissions (cf. the case of region 2 in Table 3.4). The other troublesome result of this sensi- tivity analysis is that if the reference year goes as far back as the 1970, the developing countries that are in the middle of their economic and industrial development are forced to achieve twice the amount of reduc- tions than if the present is chosen as the reference year (cf. regions 7 and 8 in Table 3.4). A reassuring result of the analysis is, however, that the relative position and reduction requirements of different regions are invariant to small changes in the reference year of say, between 1985 and 1988 and are also robust when other GHGs are con- sidered. 8.4. Cutbacks Proportional to Past Contributions According to the logic of differentiated responsibility, the scenario defines future cutbacks in direct proportion to the respective share of each region in the anthropogenic increase of atmospheric concentra- tions of GHGs. For example, if a particular region is responsible for ten percent of the increase in atmospheric concentration of C02 from -45 - the pre-industrial levels of 280 to current 353 ppmv, then it has to bear a ten percent share in the total global reduction of absolute emission levels. Here, again we assume a reduction to 4 Gt C or C-equivalent emissions level by the year 2050. Table 3.6 gives the historical contributions to the concentration increase in percentage of the world total (of 100 percent) by the 13 regions for (energy and) industrial C02, all C02 emissions, and for combined C02 and CH4 emissions. The assessment is based on analysis using the Parametric Framework* and includes anthropogenic emis- sions since 1800. This period basically covers the whole history of industrialization and therefore also reflects differentiated benefits incurred through deposition of carbon in the atmosphere by different countries. Industrialized countries have generated an overproportional share of CO2 increase and have presumably thereby also benefited in achieving their current high standards of living and affluence. Together they account for 84 percent of industrial (and energy) atmospheric C02 concentration increase. Some regions apparently bear almost no histori- cal responsibility in the concentration increase, with shares ranging between one and two percent. This includes five of the seven develop- ing regions. Their grand total share is a mere 16 percent. This should also be compared with the uneven distribution of the world's inhabi- tants with more than 80 percent of the current population living in regions with having historically less than a 20 percent share in concen- trations increase. There are slight shifts in this unequal distribution of historical emissions between the "North" and the "South' if other anthropogenic sources of greenhouse gases are added. For all sources of C02, the share of developing countries increases to 32 percent and with methane to 33 percent. It is interesting to note that the historical contributions to current con- centrations are closely related to the pattern of current emissions in the regions. Low shares in historical contributions are highly correlated with low current emissions, and the relative change in position of vari- ous regions when other sources of greenhouse gases are added is also * Put 002 emisslons are accoted for with a hybrid model of an airborne fraction approach comblaed with a long-tera ocea uptake component (cL Grabler aad il, 1991). For purposes of accounting pat contributions to atmospheric concentration lacrese only the ocan uptake part of the model b elevant. We have adopted an ocean uptake coastant of 300 yeas which Implies that historical carbon en lasions remala- ing In the atmosphere are discounted by 0.3 percent per year. For methane emiuloas we an atmospheric removal rate of 25 percent per year (corresponding to a mean atmosphedic rsidence time of ten years) to calculate emissious remaining In the atmosphere. All these parameters for accounting historical emissiess can be nodiled In the Parametric framework. Table 3.6. Overview of emission reduction scenario (to 4 Gt C or C-equivalent) by 2050. Criterion used: Reduction proportional to past contribution. Comparison of regional past contributions (%), and 1988 and 2050 abiolute emission levels, in Gt C or C-equivalent. Past contribution Enission in 1988 EmIs.* in 2050 1800-1988 In % Gt C (C*) Gt C (CO) Industrial Total CO2 + C4 Industrial Total COs + CH4 Industrial Total CO2 + C4 COs C02 CO2 CO_ CO CO2 1 OECD NA 33.2 29.7 29.2 1.43 1.43 1.64 0.88 0.71 0.44 2 OECD EU 26.1 16.6 16.4 0.85 0.85 1.00 0.41 0.45 0.32 3 Eastern EU 5.5 4.8 4.7 0.36 0.36 0.42 0.27 0.25 0.22 4 USSR 14.1 12.5 12.4 1.09 1.09 1.28 0.85 0.78 0.76 A Japan 3.7 2.3 2.3 0.27 0.27 0.29 0.21 0.21 0.20 6 Oceania 1.1 1.9 1.9 0.07 0.07 0.11 0.05 0.03 0.03 7 China 5.5 6.0 6.3 0.61 0.61 0.92 0.52 0.46 0.66 8 IndIa 1.6 4.5 4.8 0.17 0.17 0.41 0.14 0.07 0.21 9 Other Asia 1.5 5.0 5.2 0.16 0.47 0.58 0.13 0.35 0.36 10 NAME* 2.2 1.7 1.8 0.24 0.24 0.30 0.21 0.20 0.22 11 Other Affica 1.6 5.2 5.2 0.12 0.27 0.42 0.10 0.15 0.20 12 Brazil 0.7 3.3 3.3 0.06 0.22 0.30 0.05 0.14 0.17 13 Other LatAM 3.2 6.5 6.5 0.24 0.35 0.47 0.18 0.20 0.20 sNorths (1-6) 83.8 67.8 66.9 4.07 4.07 4.73 2.67 2.43 2.03 *South* (7-13) 16.2 32.2 33.1 1.60 2.34 3.39 1.33 1.57 1.97 World 100.0 100.0 100.0 5.66 6.41 8.12 4.00 4.00 4.00 *North Africa and Middle eas -47- very similar. Thus, the current distribution of emissions is also a good "proxy" for differentiated historical responsibility of various regions. Highly industrialized countries are responsible for most of the past con- tributions, while populous developing countries bear negligible respon- sibility. However, their relative positions are rather sensitive to the inclusion of biota sources of CO2 and CH4 into the considerations. Table 3.6 also shows the distribution of 4 Gt C (and C-equivalent) emissions in 2050 according to. the criterion of reductions proportional to past contributions. Clearly, all regions need to reduce, but the reductions are much more substantial in the "North". It is apparently not in the interest of any region to include biota sources of C02 and CH4 into the accounting process since all regions are worse-off. How- ever, should the total emissions to be allocated by 2050 also increase accordingly with the addition of other greenhouse gases then it would indeed be in the interest of the "North" that they are considered. In any case, this scenario improves the relative position of the "South" compared with the current distribution of the emissions, but its disad- vantage is that it does not allow for any emission increases even in those regions with extremely low current levels. Carbon dioxide is an especially long-lived gas in the atmosphere. This is the main reason why emissions data going back to the beginning of the Industrial Revolution have to be invoked to assess the past contri- bution to current atmospheric concentration. Furthermore, the addi- tion of methane to the total global warming potential of CO2 and CH4 is also based on a number of critical assumptions as explained above. These include the global warming potential of CH4 relative to CO2 assumed to be 21 for the purposes of this assessment, and the lifetime of CH4 in the atmosphere (assumed here to be reduced by 25 percent of the remaining amount each year). In order to test the sensitivity of our analysis of past contributions to current concentrations by various regions, Table 3.7 reports the results of varying some of these model assumptions. It is interesting to note that the overall result is rather invariant to these assumption changes. For example, the share of the "North* is contained within the interval of 63 to 70 percent for a com- bination of changes in these two parameters and a reduction in the his- torical observation period by almost 30 years. Thus, the differentiated historical responsibility is a robust concept if defined as the relative contribution of different regions to current (or recent) anthropogenic concentration increases of GHGs. Table 3.7. Sensitivity analysis for criterion: Reduction proportional to past contribution. Regional shares in past concentration increase of all GHGs (02 + CH4), in percent. Sensitivity: Variation of methane equivalence factor, decay rate, and time period of calculation. CH4 GWP 21 21 21 58 21 58 CH4 Decay Rate, %/yr 25 25 25 10 10 25 Time period: 1800 to: 1988 1980 1970 1988 1988 1988 1 OECD NA 29.2 30.7 33.4 27.0 28.7 28.3 2 OECD EU 16.4 16.8 17.5 15.4 18.1 16.0 8 Eastern EU 4.7 4.5 4.5 4.6 4.7 4.6 4 USSR 12.4 11.7 11.1 12.0 12.3 12.3 5 Japan 2.3 1.9 1.3 2.1 2.2 2.2 6 Oceania 1.9 2.1 2.1 1.9 1.9 1.9 7 China 6.3 5.9 5.5 7.4 6.6 6.8 8 India 4.8 5.2 6.0 5.7 5.1 5.2 9 Other Asia 5.2 4.8 4.2 6.4 5.5 5.6 10 NAME* 1.8 1.5 1.1 1.9 1.8 1.8 11 Other Africa 5.2 5.1 4.9 5.6 5.3 5.4 12 Brazil 3.3 3.2 2.8 3.3 3.3 3.3 13 Other LatAm 6.5 6.6 5.6 8.7 6.5 6.6 North* (1-6) 66.9 67.8 70.0 63.0 65.9 65.4 "South" (7-13) 33.1 32.2 30.0 37.0 34.1 34.6 World 100.0 100.0 100.0 100.0 100.0 100.0 *North Africa and Middle East -49- 8.5. SInk Adjusted Emlisions Global GHG sinks differ in magnitude and especially in relation to anthropogenic emissions. That the absorptive capacity of the global GBG sinks is overstretched is reflected in the increasing concentrations of all GHGs in the atmosphere. Sinks for carbon dioxide are estimated to approximate to about 3 Gt C, with the distribution between oceanic and terrestrial carbon sinks subject to considerable scientific uncer- tainty. The most important methane sink is the atmosphere (CH4 des- truction by OH radicals). If natural emissions of some 240 Tg methane (from e.g., natural wetlands, wild animals, termites, etc.) are sub- tracted from the natural methane sinks (in the IPCC 1990 report assumed to be 500 Tg), one obtains the residual sink available to absorb anthropogenic emissions. In our case, the methane sink is assumed to be around 260 (500-240) Tg CH4 (about 1.5 Gt C- equivalent) or about 80 percent of estimated current anthropogenic methane emissions. The sink adjusted scenario for carbon emissions is, with 3 Gt C, lower than the 4 Gt C assumed for the other scenarios. The total GHG emis- sion level in the scenario is actually higher because of the additional methane sinks (of about 1.5 Gt C-equivalent). However, the two sinks although additive are not substitutable in terms of allocating emissions between the total global or regional GHG emission targets. Conse- quently, allocations of carbon and methane sinks had to be considered separately in the calculations with the Parametric Framework. There are of course a number of alternative ways of allocating sink adjusted emission levels among the 13 world regions. Here, we first analyse the consequences of a per capita allocation of global GHG sinks and a reduction of the emissions exceeding these levels. In a sensitivity analysis, this scenario is compared to cases where the global GHG sinks are allocated on a per unit land area, and a combination of land and per capita allocation criteria. Table 3.8 shows a comparison of the sink adjusted emission allocation for 2050 with actual levels in 1988. Access to natural GHG sinks is dis- tributed among the regions on an equal per capita basis. Therefore, the allocation is the same as in the case of the first criterion (per capita emission levels) analyzed above, except that here only the total sink is specified and the emission levels are the result of the calculation in the Parametric Framework. The allocations for 2050 are very low - 50- compared with other cases and would indeed represent almost impossi- ble targets to achieve. In fact, the regional allocations for 2050 of about 314 kg C per capita are lower than current per capita C02 emissions in all regions except India (220 kg C per capita in 1988). If biota sources of C02 are excluded, then in addition to India (region 8), regions 9 and 11 are today also below the target per capita level for 2050. The fact that present per capita emissions in most developing countries exceed the per capita sink allocation by 2050 (with a doubled world popula- tion) illustrates that GHG sink allocations on a per capita basis would disallow most developing countries from increasing their absolute GHG emissions over present levels (cf. Table 3.8). The achievement of such drastic reductions of global emissions as implied by a sink adjusted emission criterion without the possibility for higher future emissions in the developing countries thus appears rather unrealistic and definitely undesirable from the perspective of further economic growth in the "South". The combined C02 and CH4 sinks are assumed to be somewhat more generous with about 4.5 Gt of C-equivalent per year. On a per capita basis, this increases the emission allowances to about 470 kg of C- equivalent per person and year. However, the current combined emis- sions of C02 and CH4 are also higher so that this limit represents per capita reductions from current levels in aU regions. The required reduc- tions are impressive in absolute terms as well. Many of the developing regions are required to make substantial reductions, while some more developed regions would be required to sustain reductions to the tune of more than five percent per year. For example, region 1 would need to reduce its emissions by over a factor of 14 between now and 2050. On balance this kind of scenario is too extreme and is less preferable than explicit equal per capita emission allocation according to criterion one. As a sensitivity analysis to a per capita sink allocation, we have exam- ined the allocation of the 3 Gt natural carbon sinks on the basis of land area and also the separate allocation .of terrestrial and oceanic carbon sinks. The results are summarised in Table 3.9 which shows the current regional absolute emissions as well as by the two different car- bon sink allocation criteria - total carbon sinks by land area of each region and by allocating terrestrial sinks (half of the emissions) on land area basis and oceanic carbon sinks (also about 1.5 Gt C) as a global commons on a per capita basis. The sink allocation per unit land area Table 3.8. Overview of emission reduction scenario. Criterion used: Reduction to natural sinks adjusted emissions (3 Gt C for CO, and 1.5 Gt C-equivalent for CH4) by 2050. Comparison of 1988 and target year absolute emission levels, in Gt C or C-equivalent. Industrial CO2 All CO2 CH4 CO2 + C4 In Gt C In atC n Gt C-equivalent In G C-equivalent 1988 1988 2050 1988 2050 1988 2050 1 OECD NA 1.43 1.43 0.10 0.21 0.05 1.84 0.15 2 OECD EU 0.85 0.85 0.12 0.15 0.00 1.00 0.18 8 Eastern EU 0.36 0.36 0.04 0.06 0.02 0.42 0.06 4 USSR 1.09 1.09 0.11 0.19 0.06 1.28 0.17 5 Japan 0.27 0.27 0.04 0.02 0.02 0.29 0.06 6 Oceania 0.07 0.07 0.01 0.04 0.00 0.11 0.01 7 ChIna 0.61 0.61 0.52 0.31 0.26 0.92 0.78 8 India 0.17 0.17 0.48 0.24 0.24 0.41 0.72 9 Other Asia 0.16 0.47 0.52 0.11 0.26 0.58 0.78 10 NAME 0.24 0.24 0.28 0.06 0.14 0.30 0.42 11 Other Africa 0.12 0.27 0.53 0.15 0.28 0.42 0.79 12 Brazil 0.06 0.22 0.08 0.08 0.04 0.30 0.12 13 Other LatAm 0.24 0.36 0.18 0.11 0.09 0.47 0.27 "North* (1-6) 4.07 4.07 0.42 0.66 0.21 4.73 0.63 *South* (7-13) 1.60 2.85 2.58 1.04 1.29 3.39 3.87 World 5.06 8.41 3.00 1.71 1.50 8.12 4.50 Narth AMs and Midd Eask Table 3.9. Sensitivity analysis for criterion: Reduction to natural sinks adjusted emissions (3 Gt C carbon sink) by 2050. Absolute CO2 emissions per region, 1988 and 2050. Sensitivity: Variation of carbon sink allocation criteria: total sinks per land area, and terrestrial sinks per land area and ocean sinks per capita, in Gt C. 3 Gt carbon sinks allocation 1.5 Gt terrestrial and 1.5 Ct oceanic sink 1988 Total sinks CO2 emissions Per land Terrestrial Oceanic ct C area Per land area Per capita Total 1 OECD NA 1.43 0.43 0.22 0.05 0.27 2 OECD EU 0.85 0.10 0.05 0.06 0.11 3 Eastern EU 0.36 0.02 0.01 0.02 0.03 on 4 USSR 1.00 0.50 0.25 0.06 0.31 5 Japan 0.27 0.01 0.00 0.02 0.02 6 Oceania 0.07 0.18 0.09 0.00 0.09 7 China 0.61 0.21 0.11 0.26 0.37 8 India 0.11 0.07 0.04 0.24 0.28 9 Other Asia 0.47 0.18 0.09 0.26 0.35 10 NAME* 0.24 0.28 0.14 0.14 0.28 11 Other Africa 0.27 0.55 0.28 0.26 0.54 12 Brazil 0.22 0.19 0.10 0.04 0.14 13 Other IatAm 0.8 0.30 0.13 0.09 0.22 "North* (1-6) 4.07 124 0.62 0.21 0.83 aSouthe (7-13) 2.35 1.76 0.88 1.29 2.17 World 6.41 3.00 1.50 1.50 3.00 *North Africa and Middle East - 53 - gives higher emission allocations to large regions, which often results in lower emissions for the more developed regions. However, many of the developing regions would also incur reductions including regions 7, 8, 9, 12 and 13. This allocation scheme of natural sinks does not lead to any obvious redistribution of emission levels along the "North-South" divide, but it does result in differential effects within the two groups of regions by favoring less populous regions whether they are in the "North" or "South". The fact that the per unit land allocation cri- terion penalizes regions with high population densities and high popula- tion growth probably makes it inappropriate for the allocation of emis- sions under a global reduction scenario. Allocating terrestrial and oce- anic carbon sinks separately on the other hand somewhat improves the situation for more populous countries but does not significantly change the overall "North-South" emission divide that emerged from a simple per capita allocation criterion (Table 3.8 above). Hence, this subvari- ant of the sink allocation criteria introduces additional complexity into the debate without yielding widely different results from a simple per capita criterion. 4. Comparison of Criteria Tables A.1 to A.8 in the Appendix summarize the differences in regional GHG emissions for a common reduction scenario to 4 Gt C (C-equivalent) by the year 2050. They compare the results of three reduction criteria of the four analyzed with the Parametric Framework: equal percentage cuts (with two different base years), cutbacks propor- tional to past contributions, and equal emission rights per capita scenarios. Comparisons are made for fossil fuel and industrial C02, and all anthropogenic GHG (C02 and CH4) emissions, respectively. Absolute and per capita emissions, as well as absolute and per capita emission reductions (or increases) between the target (1988) and target (2050) years are also given for the two categories of GHG emissions. In the following, we briefly review the different allocation scenarios analysed with respect to their consequences for absolute emission lev- els, required absolute emission reductions, and finally their distributive effect as reflected in differences in per capita emission levels. Table 4.1 shows absolute levels of industrial C02 emissions for the 13 world regions in 1988 and for the three alternative allocation scenarios in the year 2050 assuming global emission reductions to a target value of 4 Gt C. Table 4.2 gives the same comparison for all anthropogenic -54- C02 and CH4 emissions combined. The salient feature of the com- parison of different allocation scenarios is that it reveals both general tendencies, which were to be expected on principle considerations (e.g., per capita criteria tend to favor developing countries in GHG reduction scenarios) with (to a degree) surprising results which emerge only once the quantitative implications and differences between various criteria have been calculated. The largest principal difference among the criteria analyzed is whether they imply emission reductions by all regions/countries (though at different rates), i.e., are proper reductive criteria, or whether they are distributive criteria (i.e., allocate emission rights), from which the required reductions are then inferred. Reductive criteria result in emis- sion reductions in all regions, whereas distributive criteria - depending on current emissions levels - can imply both reductions or increases in GHG emissions. From the four criteria investigated, only the criterion of converging per capita emissions (or the equivalent per capita sink allocation) is distri- butive. Consequently, it is also the only one where both increases and decreases in regional emissions result with respect to the target year. For developing countries, it is also the only criterion that would allow future emission increases to raise per capita energy consumption levels. Even under the (rather stringent) global emission reduction assump- tions adopted here (4 Gt C) all developing countries could increase their absolute emissions, provided only industrial C02 emissions are considered. Emissions from the "South' would double in such a scenario to some 3.4 Gt C, whereas emissions from the "North' would have to be decreased drastically to 0.6 Gt C (down from the current 4.1 Gt). The situation is somewhat different when biotic carbon and methane emissions are also considered for the same emission reduction scenario to 4 Gt C-equivalent. Here, all developing countries taken together would only be allowed a stabilization of their current absolute emissions, despite a per capita allocation criterion, simply because the required global reduction (to less than 50 percent of current emissions) is so large. Only four developing regions (8 to 11) would be allowed relatively modest absolute emission increases: about 20 percent above 1988 levels for regions 9 and 10, and some 60 percent (from compara- tively low levels) for regions 8 and 11. The developing regions 7, 12, and 13 (China and all of Latin America) would even have to bear a decrease. Table 4.1. A comparison of different allocation criteria for CO2 reduction strategies (to 4 Gt C by 2050), fossil fuel and industry CO2 emissions, in Gt C. Equal Percent Cuts Cutbacks Equal Emission 1988 Proportional to Rights Per Capita Emissions 1988 Base 1980 Base Past Contribution (by 2050) 1 OECD NA 1.43 1.01 1.09 0.88 0.13 2 OECD EU 0.85 0.80 0.76 0.41 0.16 8 Eastern EU 0.386 0.25 0.27 0.27 0.06 4 USSR 1.09 0.77 0.71 0.85 0.15 5 Japan 0.27 0.19 0.20 0.21 0.05 *o 6 Oceania 0.07 0.05 0.05 0.05 0.01 7 China 0.61 0.43 0.32 0.52 0.89 8 India 0.17 0.12 0.08 0.14 0.84 9 Other Asia 0.16 0.11 0.09 0.18 0.70 10 NAME* 0.24 0.17 0.14 0.21 0.37 11 Other Africa 0.12 0.09 0.08 0.10 0.70 12 Brazil 0.06 0.04 0.04 0.05 0.11 13 Other LatAm 0.24 0.17 0.17 0.18 0.24 "North* (1-6) 4.07 2.87 3.08 2.67 0.56 'South' (7-13) 1.60 1.13 0.92 1.33 3.44 World 5.68 4.00 4.00 4.00 4.00 *North Africa and Middle East Table 4.2. A comparison of different allocation criteria for GHG reduction strategies (to 4 Gt C-equivalent by 2050), CO2 and CH4 emissions (all sources), in Gt C-equivalent. Equal Percent Cuts Cutbacks Equal Emission 1988 Proportional to Rights Per Capita Emissions 1988 Base 1980 Base Past Contribution (by 2050) 1 OECD NA 1.64 0.81 0.76 0.44 0.13 2 OECD BU 1.00 0.49 0.53 0.32 0.18 3 Eastern EU 0.42 0.21 0.19 0.22 0.06 4 USSR 1.28 0.683 0.52 0.76 0.15 5 Japan 0.29 0.14 0.13 0.20 0.05 6 Oceania 0.11 0.05 0.08 0.03 0.01 7 China 0.92 0.45 0.386 0.86 0.89 8 India 0.41 0.20 0.17 0.21 0.84 9 Other Asia 0.58 0.28 0.39 0.386 0.70 10 NAME* 0.30 0.15 0.11 0.22 0.37 11 Other Africa 0.42 0.20 0.30 0.20 0.70 12 Brazil 0.30 0.15 0.13 0.17 0.11 13 Other LatAm 0.47 0.23 0.33 0.20 0.24 'North* (1-0) 4.73 2.33 2.20 1.97 0.58 "South" (7-18) 3.39 1.67 1.80 2.03 8.44 World 8.12 4.00 4.00 4.00 4.00 *North Africa and Middle East - 57- Thus, the major conclusion of the comparison between distributive and reductive criteria is that from the perspective of the developing coun- tries distributive criteria, especially when based on a per capita basis, are clearly preferable because they are the only ones that allow absolute emission increases in the "South". Conversely, the difference between the various reductive criteria investigated is comparatively minor (cf. the discussion below). Offering a compromise in differentiated GHG reduction targets (e.g. by considering different historical responsibili- ties) may thus not be sufficient to bridge the significant "North-South" divide emerging from per capita emission allowance scenarios vis il Vi other reduction scenarios. It is important to reiterate here the observation made in previous sec- tions when analyzing the implications of different allocation criteria under the emission reduction schemes. We discovered a surprising degree of invariance with respect to some of the basic assumptions of the analysis. This is mirrored for instance in Table 4.2 where the emis- sions in 2050 under equal percent cuts are compared with two different reference years, 1988 and 1980 respectively. We also analyzed the resulting changes from larger variations in the reference year going back to 1970. The resulting redistribution of emissions is minimal in most cases. For example, in Tables 4.1 and 4.2, the emissions in the "North" change by seven percentage points if the base year is varied between 1988 and 1980. Another similarity can be observed among what we have called reduc- tive criteria (equal percent cuts, and cutbacks proportional to past con- tributions). They all result in basically the same distribution of emis- sions in the target year 2050. The main exception here is region 2 (OECD Europe) that shows larger variance between the equal percent cuts and cutbacks proportional to past contributions. That the similar- ity in other cases is so close is indeed a counter-intuitive result upon first reflection. However, a closer analysis indicates that there is a fun- damental reason for this similarity which is inherent in the nature of global GHG emissions, namely, the emissions of most GHGs have increased at almost exponential rates since the beginning of the Indus- trial Revolution and in particular since World War I. Exponential growth portrays an interesting property: its integral is proportional to the function itself. In our case, this means that emissions in any partic- ular reference year should have a similar distribution among different regions as do the respective cumulative emissions up to that reference year. Thus, the resemblance of emission distribution between the equal - 58- percent cuts and cutbacks proportional to past contributions indicates that historical increases of anthropogenic sources of GHGs have been rather close to an exponential growth path in most of the world's regions. For all practical purposes it would be easier and more prudent to use an equal percent cuts criterion instead of the much-more- difficult-to-determine allocation according to the differentiated histori- cal responsibility, although on the surface the latter appears to many observers to be inherently more "equitable". Figure 4.1 summarizes the obtained results by contrasting 1988 emis- sions for selected regions and countries with the resulting regional emis- sion allowances in a global reduction scenario to 4 Gt (C or C- equivalent) based on the three allocation criteria. The figure also illus- trates the effect of the comprehensiveness of GHGs considered. In the case of reductive criteria it is in the interest of the "North" to consider only industrial CO2 emissions. Conversely, it is in the interest of the "South" to consider all sources of C02 and methane as a calculation base for emission reduction. In the case of a distributive criterion the regional interests are similar: it is in everybody's interest to include as few GHGs as possible. The similarity between the reductive criteria is preserved if the com- parison is made on a per capita basis, as shown in Tables 4.3 and 4.4. On the other hand, the contrast between the reductive criteria versus the distributive criterion (i.e. allocation on the basis of equal emission rights per capita) is even more transparent (cf. Figure 4.2). In the reductive criteria scenarios, the global inequalities are aggravated: the difference between the per capita emission levels of the "North" and the "South` increases from about a factor of eight at the present time to between 15 and 20 in the year 2050 (see Table 4.3). The global dispari- ties also increase when all GHGs are considered albeit by somewhat lower factors: from the present factor of about 4.5 to between 6 and 9 in the year 2050 (see Table 4.4). By definition, the allocation criterion leads to equalization of the per capita emissions throughout the world. In fact, the average per capita emissions in the "Southern" regions stay the same as in the base year: a bit over 400 kg of C per inhabitant. The above results are also mirrored in the absolute changes in emission levels between the reference and target years for the 13 world regions. (cf. Appendix) Only the allocation criterion of equal emission rights per capita actually leads to an emission increase in all developing regions (7 to 13) while in all other cases emissions decrease throughout * 59- 2.0 1.8 . A 1988 emissions A B equal % cuts 1.6 - C CPPC D equal per capita emissions 1.4 . only industrial C02emissions 1.2 all GHG emissions BC 1.0 - C 0.8 - M 0.4 - 0.4 0.2 - E1 DL I t1 I PF North other USSR China India Brazil America OECD Figure 4.1 A comparison of three allocation criteria for GHG reduction strategies (to 4 Gt C or C-equivalent by 2050) for selected regions/countries, comparison to 1988 emissions, and impact of consid- ering only industrial C02 emissions or all C02 and CH4 emissions, in Gt C or C-equivalent per region/country. the world. As concluded above, the extent of decrease is quite similar between the reductive scenarios analyzed. Figure 4.3 illustrates the magnitude of the "North-South divide" in demographics, economics, and historical and current GHG emissions. As such its serves as a "barometer" quantifying various pressures on distributional issues inherent in any climate stabilization strategy. Disparities extend beyond those illustrated in Figure 4.3. They entail disparities between GHG sources and sinks, between benefits accruing from GHG emissions and possible damage from climate change, between different past, present, and future generations and more gen- erally between any "winners" and "losers" of GHG control policies. Table 4.3. A comparison of different allocation criteria for C02 reduction strategies (to 4 Gt C by 2050), per capita fossil fuel and industrial C02 emissions, in tons C per capita. Equal Percent Cuts Cutbacks Equal Emission 1988 Proportional to Rights Per Capita Emissions 1988 Base 1980 Base Past Contribution (by 2050) 1 OECD NA 5.28 S.26 S.37 1.85 0.49 2 OECD EU 1.2 1.61 1.06 1.11 0.42 3 Ea&tern EU 5.17 1.91 1.97 0.09 0.41 4 USSR 5.88 2.11 1.87 2.44 0.42 5 Japan 1.20 1.51 1.55 1.64 0.42 8 Oceania 5.69 2.10 1.88 2.18 0.41 7 China 0.56 0.16 0.19 0.5t 0.41 8 India 0.11 0.08 0.05 0.09 0.42 9 Other Asia 0.21 0.07 0.05 0.08 0.40 10 NAME* 0.7$ 0.19 0.16 0.1$ 0.42 11 Other Africa 0.15 0.05 0.05 0.06 0.41 12 Brazil 0.41 0.16 0.15 0.18 0.41 13 Other LatAm 0.84 0.S0 0.19 0.42 0.42 *North' (1-4) 8.41 2.16 1.22 1.01 0.41 "South* (7-13) 0.41 0.14 0.11 0.16 0.41 World 1.11 0.41 0.40 0.41 0.41 *North Africa and Middle East Table 4.4. A comparison of different allocation criteria for GHG reduction strategies (to 4 Gt C-equivalent by 2050), per capita CO2 and CII4 (all sources), in tons C-equivalent per capita. Equal Percent Cuts Cutbacks Equal Emission 1988 Proportional to Rights Per Capita Emissions 1988 Base 1980 Base Past Contribution (by 2050) I OECD NA 0.06 2.61 .46 141 0.42 2 OECD EU .62 1."* 1.45 0.87 04 3 Eastern EU 5.65 1.54 1.45 1.67 0. 4 USSR 4.50 1.7S 144 1.10 0.41 5 Japan 1.57 1.15 1.04 1.55 0.42 6 Oceania 5.58 .t 2.60 1.9 0.42 7 China 0.85 0.28 0." 0.40 0.42 8 India 0.51 0.15 0.11 0.14 041 9 Other Asia 0.75 0.17 0.25 0.1* 0.4* 10 NAME* 0.90 0.17 0.15 0.15 0.41 11 Other Africa 0.87 0.1* 0.18 0.1t 0.4# 12 Brazil 1.09 0.55 0.48 0.61 0.41 13 Other LatAm 1.69 0.4* 0.59 0.56 0.4 *North* (1-) 5.97 1.75 1.66 1.49 0.49 "Southo (7-18) 0.87 0.0 0.22 0.S 0.48 World 1.60 0.41 0.41 0.41 0.4 *Noth Africa and Middle EaNt 7.0 A A 1ess emissions 8 equal% cuts C CPPC D equal per capita emissions 5.0 - only industrial CO2emisslons all GHG emissions 4.0 - 1.0 - 0.0 - 0.0 - --' ______ North other USSR China India Brazil America OECD Figure 4.2 A comparison of three allocation criteria for GHG reduction strategies (to 4 Gt C or C-equivalent by 2050) for selected regions/countries. Comparison on per capita basis (cf. Figure 4.1 above), in ton C or C-equivalent per capita. The different criteria investigated in the present study are mere illus- trations of possible outcomes from different GHG allocation and con- trol regimes. The corresponding political process is likely to take con- siderable time and its results should rather be judged on its success in reaching an agreement at all - despite all disparities - than whether it satisfies spure' theoretical equity and fairness principles from a philo- sophical perspective. The criteria studied here and the Parametric Framework developed could assist the process by identifying possible areas of convergence of differences in interests, as well as by quantifying the implications of the different regimes proposed so that possible areas of conflict and priority for negotiation can be identified in an early phase. The approach can be also useful for identifying and comparing regional programs for GHG emission mitigation. - 63 - "North" "Southu 0 10 20 30 40 50 00 70 80 90 100 % GDP (mkt.ex.r.) 1988 GDP (PPP) 1988 Population 1800-1988 Population 1988 7___7_777 Pop. under age 18,1988 7/ Industrial C02 1800-1988 AlI C02 1800-1988 Industrial C02 1988 AlC02 988 C02+CH4 1988 AII GHGs 19882) 1) Range includes 0.8 to 2.6 Gt C blots emissions In the 'South' 2) Apprimion 100 90 80 70 60 50 40 30 20 10 0 % Figure 4.3 The greenhouse "barometer". Regional shares ("North" versus "South') in economic activity, population, and GHG emissions. 5. Conclusions An analysis was made of the quantitative implications of four green- house gases emission allocation criteria for 13 world regions, assuming a reduction of global emissions to 4 Gt C (C-equivalent) by the year 2050. Additional sensitirity analyses were performed for each of the criteria. Four major results were obtained: 1. The most important finding is that there are two classes of alloca- tion criteria - we have called them distributive and reductive. Dis- tributive criteria allocate limited future emissions to individuals or countries, while reductive ones allocate only required emission reductions. Equal per capita emission rights and natural sink adjusted emissions are examples of distributive criteria. Equalizing emission rights places a large burden on the 'North' and gives -64- more generous emission allocations to the "South". Thus, future economic and social development in the "South" is not jeopardized by the need for stringent GHG emission reductions. However, per capita allocation criteria do not provide incentives to curb popula- tion growth. Across the board percentage cuts and cutbacks pro- portional to past contribution are examples of reductive criteria. They are effective in lowering GHG emissions across all regions but are insensitive to development needs and lead to widening per cap- ita gaps due to different rates of future population growth. The largest differences in emission allocations are obtained between these two generic classes of criteria, especially when distributive criteria are based on a per capita basis (such as in this report). Changes to other salient parameters in the analysis yield compara- tively smaller differences. 2. Differences in emission allocations obtained were smaller within each of the two classes of allocation criteria. They were sufficiently small that in each category the simpler criterion (of the two analyzed) was clearly preferable. For example, across-the-board percentage cuts ("grandfathering") achieve similar future alloca- tion distribution as cutbacks proportional to past contribution. Historical responsibilities and current emissions have a very similar structure across the world regions and between "North" and "South'. In many ways, this is fortunate because in practice it is very difficult to assess the historical responsibility of individual countries, whereas current emissions are much easier to estimate. Similarly, equal per capita emission rights are preferable over allo- cation of natural sink adjusted emissions, due to the complexity and immense uncertainty involved in allocating (partly) unknown global GHG sinks. 3. A consistent finding in the analysis was that the inclusion of different GHGs (comprehensiveness) had a smaller effect on emis- sion allocation than the difference between the two generic classes of allocation criteria. Furthermore, regional interests with respect to comprehensiveness vary systematically with the type of alloca- tion criterion considered. Therefore, the basic principle of the allo- cation is more important than the comprehensiveness of an alloca- tion scheme. -65 - 4. The smallest of all variations in emission distribution resulted from altering the reference year. Variations in the reference year from 1988 to 1980 made comparatively little difference on the results obtained. Thu, the choice of the base year is less important than the comprehensiveness of GHGs considered, and the latter, in turn, is less important than the choice of the generic class of allocation criteria. From the perspective of this analysis, a number of priorities for future research can be derived. First, analysis should concentrate on the two generic classes of allocation criteria identified rather than on a detailed study within a given class. In addition, any design of new (or multiple) allocation criteria should preferably also include incentives, such as efficiency improvements, conservation, or sustainable population development. Second, required improvements in data should focus on better quality and disaggregation of non-industrial and subsistence level GHG emissions, and refinement of the regional breakdown of the analysis. This would allow for a better distinction between different GHGs as a function of the possibilities for policy intervention (e.g. industrial C02 emissions versus subsistence rice paddy farming), and better capture differences in the socio-economic development status among regions (e.g. between oil exporting and importing countries or between developing and "new industrializing" within a particular region). Better regional differentiation might also facilitate application of different allocation principles to different group of countries. Third, and perhaps most importantly, work should focus on the dynamic tran- sition paths implied by different allocation criteria. All of our comparis- ons were based on two snapshots, the reference and the target year. 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DIFFERENT ALLOCATION CRITERIA FOR CO2 REDUCTION STRATEGIES (to 4 Gt C by 2050) Fossil Fuel and Industry CO, Ot C Equal Percent Cuts Cutbacks Equal Emission .1988 Proportional to Rights Per Capita Emlissions 1988 Base 1980 Base Past Contribution (by 2050) 1 OECD NA 1.43 1.01 1.09 0.88 0.13 2 OECD EU 0.85 0.60 0.76 0.41 0.16 3 Eastern EU 0.36 0.25 0.27 Q.2T 0.06 4 TJSSR 1.09 0.77 0.71 0.85 0.15 5 Japan 0.27 0.19 0.20 0.21 0.05 a Oceania 0.07 0.05 0.05 0.05 0.01 7 China 0.61 0.43 0.82 0.52 0.69 8 India 0.17 0.12 0.08 0.14 0.64 9 Other Asia 0.16 0.11 0.09 0.13 0.70 10 NAME* 0.24 0.17 0.14 0.21 0.37 11 Other Africa 0.12 0.09 0.08 0.10 0.70 12 Brasil 0.06 0.04 0.04 0.05 0.11 13 Other LatAm 0.24 0.17 0.17 0.18 0.24 "North* (1-6) 4.07 2.87 3.08 2.67 0.56 4South* (7-13) 1.60 1.13 0.92 1.33 3.44 World 5.66 4.00 4.00 4.00 4.00 *Narth AfMica ad Midde East DIFFERENT ALLOCATION CRITERIA FOR CO2 REDUCTION STRATEGIES (to 4 Gt C by 2050) CO2 and CH4 (all sources), Gt C equivalent Equal Percent Cuts Cutbacks Equal Emission 1988 Proportional to Rights Per Capita Emissions 1988 Base 1980 Base Past Contribution (by 2050) 1 OECD NA 1.64 0.81 0.78 0.44 0.13 2 OECD EU 1.00 0.49 0.53 0.32 0.16 8 Eastern EU 0.42 0.21 0.19 0.22 0.06 4 USSR 1.28 0.68 0.52 0.76 0.15 5 Japan 0.29 0.14 0.13 0.20 0.05 6 Oceania '0.11 0.05 0.06 0.03 0.01 7 China 0.92 0.45 0.386 0.68 0.89 8 India 0.41 0.20 0.17 0.21 0.64 9 Other Asia 0.58 0.28 0.39 0.386 0.70 10 NAME* 0.30 0.15 0.11 0.22 0.37 11 Other Africa 0.42 0.20 0.30 0.20 0.70 12 Brasil 0.30 0.15 0.13 0.17 0.11 13 Other LatAm 0.47 0.23 0.33 0.20 0.24 "Northo (1-8) 4.73 2.33 2.20 1.97 0.56 "South* (7-13) 3.39 1.87 1.80 2.03 3.44 World 8.12 4.00 4.00 4.00 4.00 *North Africa and Middle East DIFFERENT ALLOCATION CRITERIA FOR CO2 REDUCTION STRATEGIES (to 4 Gt C by 2050) Fossil Fuel and Industry CO2 Absolute Changes from 1988 Levels, Gt C Equal Percent Cuts Cutbacks Equal Emission 1988 Proportional to Rights Per Capita Emissions 1988 Base 1980 Base Past Contribution (by 2050) 1 OECD NA 1.43 -0.42 -0.34 -0.55 -1.30 2 OECD EU 0.85 -0.25 -0.09 -0.44 -0.69 3 Eastern EU 0.36 -0.11 -0.09 -0.09 -0.30 4 USSR 1.09 -0.32 -0.88 -0.24 -0.94 5 Japan 0.27 -0.08 -0.07 -0.06 -0.22 6 Oceania 0.07 -0.02 -0.02 -0.02 -0.06 7 China 0.61 -0.18 -0.29 -0.09 +0.08 8 India 0.17 -0.05 -0.09 -0.03 +0.47 9 Other Asia 0.16 -0.05 -0.07 -0.03 +0.54 10 NAME* 0.24 -0.07 -0.10 -0.03 +0.13 11 Other Africa 0.12 -0.03 -0.04 -0.02 +0.58 12 Brazil 0.06 -0.02 -0.02 -0.01 +0.05 13 Other L.A. 0.24 -0.07 -0.07 -0.06 ±0.00 ONorthw (1-6) 4.07 -1.20 -0.99 -1.40 -3.51 &South* (7-13) 1.60 -0.47 -0.88 -0.27 +1.84 World 5.06 -1.66 -1.86 -1.66 -Lao *North Africa and Middle East DIFFERENT ALLOCATION CRITERIA FOR CO2 REDUCTION STRATEGIES (to 4 Gt C by 2050) CO2 and CH4 (all sources) Absolute Changes from 198 Levels, Gt C equivalent Equal Percent Cuts Cutbacks Equal Emisalsion 1988 Proportional to Rights Per Capita Emissions 1988 Base 1980 Base Past Contribution (by 2050) 1 OECD NA 1.84 -0.83 -0.88 -1.20 -1.51 2 OECD EU 1.00 -0.51 -0.47 -0.68 -0.84 8 Eastern EU 0.42 -0.21 -0.23 -0.20 -0.386 4 USSR 1.28 -0.85 -0.78 -0.52 -1.13 5 Japan 0.29 -0.15 -0.16 -0.09 -0.24 6 Oceania 0.11 -0.06 -0.05 -0.08 -0.10 7 China 0.92 -0.47 -0.58 -0.28 -0.23 8 India 0.41 -0.21 -0.24 -0.20 +0.23 9 Other Asia 0.58 -0.30 -0.19 -0.22 +0.12 10 NAME* 0.30 -0.15 -0.19 -0.08 +0.07 11 Other Africa 0.42 -0.22 -0.12 -0.22 +0.28 12 Brazil 0.30 -0.15 -0.17 -0.13 -0.19 13 Other LatAm 0.47 -0.24 -0.14 -0.27 -0.23 "North' (1-6) 4.73 -2.40 -2.58 -2.78 -4.17 USouth' (7-13) 8.39 -1.72 -1.59 -1.38 +0.05 World 8.12 -4.12 -4.12 -4.12 -4.12 *North Africa and Middle East DIFFERENT ALLOCATION CRITERIA FOR CO2 REDUCTION STRATEGIES (to 4 Gt C by 2050) Per Capita Fossil Fuel and Industry CO2, ton C/capita Equal Percent Cuts Cutbacks Equal Emission 1988 Proportional to Rights Per Capita Emissions 1988 Base 1980 Base Past Contribution (by 2050) 1 OECD NA 5.298 9.56 9.7 2.89 0.42 2 OECD EU .2 1.61 1.06 1.11 0.4g 3 Eastern EU 8.17 1.01 1.07 5.02 0.49 4 USSR 9.89 2.11 1.87 f.94 0.42 5 Japan 5.50 1.51 1.59 1.64 042 o Oceania 8.69 5.10 1.88 .RS 0.45 7 China 0.56 0.26 0.19 0.9 0.42 8 India 0.01 0.08 0.05 0.09 0.45 9 Other Asia 0.51 0.07 0.05 0.08 0.45 10 NAME* 0.78 0.19 0.16 0.29 042 11 Other Africa 0.55 0.05 0.05 0.06 0.45 12 Brasil 0.41 0.16 0.15 0.18 0.42 13 Other LatAm 0.84 0.80 0.29 0.9 0.42 *North* (1-e) s.41 5.16 R."B ..01 0.42 "South* (7-18) 0.41 0.14 0.11 0.16 0.45 World 1.11 0.42 0.40 0.42 0.45 *North Africa aid Middle EAt DIPPERENT ALLOCATION CRITERIA FOR CO2 REDUCTION STRATEGIES (to 4 Gt C by 2050) Per Capita CO2 and CH4 (all sources), tone C equiueopita Equal Percent Cuts Cutbacks Equal Emission 1988 Proportional to Rights Per Capita Emissions 1988 Base 1980 Base Past Contribution (by 2060) 2 OECD NA 6.06 2.61 846 1.41 040 2 OECD EU 2.62 1.92 1.49 0.87 0-42 3 Eastern EU 9.65 1.54 1.4 1.67 0.4* 4 USSR 4.50 1.79 1.44 2.10 0.42 5 Japan f.57 1.19 1.04 1.55 0.42 8 Oceania 5.58 2.22 2.60 1.29 0.42 7 China 0.85 0.28 0.22 0.40 0.42 a India 0.51 0.19 0.11 0.14 0.42 9 Other Asia 0.75 0.17 0.29 0.fi 0.42 10 NAME* 0.90 0.17 0.19 0.25 0.42 11 Other Affica 0.87 0.12 0.18 0.12 0.4f 12 Brazil 2.09 0.55 0.48 0.61 0.42 13 Other LatAm 1.69 0.42 0.59 0.96 042 ONorths (1-6) 9.97 1.75 1.66 1.49 0.42 "South* (7-13) 0.87 0.20 0.22 0.25 0.42 World 1.60 0.42 0.42 0.42 0.42 *North Afic and Middle East DIPPERENT ALLOCATION CRITERIA FOR CO2 REDUCTION STRATEGIES (to 4 Gt C by 2060) Fossil Fuel and Industry CO2 Per Capita Changes from 1988 Levels, ton C/capita Equal Percent Cuts Cutbacks Equal Emission 1988 Proportional to Rights Per Capita Emissions 1988 Base 1980 Base Past Contribution (by 2050) 1 OECD NA 5.58 -5.0* -1.91 -2.45 -4.86 2 OECD WEU 5.5t -0.61 -0.26 -1.11 -1.80 3 Eastern EU S.17 -1.56 -1.20 -1.15 -5.75 4 USSR 8.8$ -1.72 -1.96 -1.49 -9.41 5 Japan 5.20 -0.69 -0.67 -0.56 -1.78 6 Oceania S.69 -1.59 -1.81 -1.46 -8.57 7 China 0.56 -0.90 -0.87 -0.24 -0.14 8 India 0.51 -0.1s -0.16 -0.12 +0.21 9 Other Asia 0.01 -0.14 -0.16 -0.18 +0.21 10 NAME* 0.7 -0.54 -0.57 -0.50 -0.81 11 Other Africa 0.53 -0.50 -0.50 -0.19 +0.17 12 Brazil 0.41 -0.25 -0.26 -0.29 -0.01 13 Other L.A. 0.84 -0.54 -0.55 -0.55 -0.45 "North* (1-6) 9.41 -1.5 -1.19 -1.40 -5.99 a aSouth* (7-18) 0.41 -0.57 -0.40 -0.25 +0.01 World 1.11 -0.69 -0.71 -0.69 -0.69 *North Africa and Middle East DIFFERENT ALLOCATION CRITERIA FOR CO2 REDUCTION STRATEGIES (to 4 Gt C by 2050) CO2 and CH4 (all sources) Per Capita Changes from 1988 Levels, tons C equio/capita Equal Percent Cuts Cutbacks Equal Emission 1988 Proportional to Rights Per Capita Emissions 1988 Base 1980 Base Past Contribution (by 2050) 1 OECD NA 6.06 -9.45 -9.60 -4.65 -5.64 2 OECD EU .6.0 -1.S0 -1.19 -1.75 -1..o 3 Eastern EU 9.65 -2.11 -f.11 -1.98 -9.59 4 USSR 4.50 -5.77 -9.06 -5.40 -4.08 5 Japan 1.97 -1.54 -1.99 -0.81 -1.05 6 Oceania 5.58 -3.46 -1.98 -4.19 -5.16 7 China 0.85 -0.57 -0.6 -0.45 -0.4s 8 India 0.51 -0.98 -0.40 -0.S7 -0.09 9 Other Asia 0.75 -0.58 -0.51 -0.5s -0.99 10 NAME* 0.90 -0.79 -0.77 -0.65 -0.48 11 Other Africa 0.87 -0.75 -0.69 -0.75 -0.45 12 Brasfl 5.09 -1.54 -1.61 -1.48 -1.67 18 Other LatAm 1.69 -1.57 -1.10 -1.97 -1.57 "North* (1-8) 9.97 -e.m5 -*.$1 -5.48 -9.55 -South' (7-13) 0.87 -0.67 -0.65 -0.61 -0.45 World 1.60 -1.18 -1.18 -1.18 -1.18 North Africa and Middle East - 81- APPENDIX II. - Data Appendix Data Sources for the GHG emission inventory of the Parametric Framework. 1. Industrial CO2 Emissions. These include C02 emissions from the burning of fossil fuels (coal, oil and natural gas) as well as emissions from flaring of natural gas and the manufacture of cement. 1950-1988. Source: Marland et al., 1989. Estimates based on UN energy balances and cement manufacturing data of the US Bureau of Mines and using the methodology developed by Mawland and Rotty (1983). An updated data base covering the period 1950 to 1988 was used. Emissions by source and per country were aggregated to the 13 world regions/countries of the Parametric Framework. 1800-1949: Fossil Fuels: Estimates adapted from Fujii (1990) and modified to the regional breakdown of the Parametric Framework. Data based on energy balances from Darmstadter et al. (1971) for the period 1925 to 1950. For earlier years, apparent consumption (produc- tion - exports + imports) based on physical output statistics from Mitchell (1980; 1982; 1983) and aggregations of time series of national energy balances were used. Data sources include: Canada: Urquhart and Buckley (1965); Germany: Schilling and Hildebrandt et al. (197$); UK and USA: NakidenoviV (1984); USSR and Tearist Russia: Fetisov (1991); all other countries: Woytinsky (1926). Emission factors to translate from apparent energy consumption to carbon emissions are based on Atsibel et al., 1988. Where required, emission factors were calibrated to yield 1950 carbon emissions consistent with the estimates of Marland et al. (1989). Pre-1950 Gas flaring and cement manufacture: Activity data from Valais. et al. (1982) and Schurr and Netschert (1960) for gas flaring, and Zimmermann (1951) and Woytinsky and Woytinsky (1953) for cement manufacture. Regional carbon emission factors of gas flaring calibrated with Marland et al. (1989) 1950 gas Baring CO2 emissions, for cement manufacture an emission factor of 0.134 tons carbon per ton cement was used. -82- 2. Blota Carbon Emiselons This includes carbon emissions due to land-use changes, i.e. carbon emissions from burning and organic decay of vegetation and carbon releases from soil in conjunction to changing land-use patterns. 1988: Conservative, low-range estimates, as discussed in Section 2.1.2 (Table 2.4) of the main text. Estimates assume zero carbon balance for temperate latitudes, and global net emissions of 800 Mt C (lower bound of IPCC range) from tropical latitudes. 1800-1980: adapted from estimates for 8 world regions made by Hough- ton and Skole (1990) based on a detailed "bookkeeping model of land- use changes and related carbon release profiles of different ecosystems. Original data were retained for regions North America, USSR, Oceania, China, and Latin America). For Western and Eastern Europe, Japan, India, ane Brazil the original Houghton and Skole (1990) data (at higher lev Is of geographical aggregation) were disaggregated. We have assuried that subregional and national biotic carbon releases are in proportion to the Houghton and Skole (1990) estimates using the respective ratios of carbon releases due to agricultural land-use conver- sions over the periods 1860-1920, and 1920-1978 from Richards et al. (1983). The latter estimate covers approximately half of the total biotic carbon releases (62.4 Gt C between 1860 and 1978) compared to 120 Gt C of the Parametric Framework over the period 1850-1985 (including also deforestation and land-use changes not related to expansion of regular cropping areas). Data between 1980 and 1988 were interpolated exponentially with the exception of Brazil where an average biot;c carbon release of 180 Mt C/year over the 1980s (Alves, 1991) was assumed. Releases in indivi- dual years have been irregular and can be substantially higher than the 10-year average assumed here. It should be noted that historical and current biotic carbon release estimates may not be comparable directly as based on different data sources using different methodologies. In particular historical carbon releases estimated by Houghton and Skole (1990) assume higher carbon content of vegetation and soil systems than suggested by the authors in later publications (cf. Houghton, 1991) and adopted as conservative estimates for the 1988 values of the Parametric Framework. -83.- 8. Anthropogenlc Methane Emisslons The Parametric Framework includes estimates of five major sources of anthropogenic methane emissions for the 13 world regions from 1950 to 1988. Longer time-series were not required due to the limited residence time of methane in the atmosphere of about 10 years. These time- series were estimated as a function of anthropogenic activity levels directly associated with the five emission categories. First, the five activity levels were derived from the appropriate data sources for the 13 regions for the period from 1950 to 1988 and then multiplied by regional emission factors by source. Thus, we have implicitly assumed that the methane emission factors have not changed substantially dur- ing this period within each of the five emission categories in the respec- tive regions. This is a strong assumption that had to be made due to the lack of explicit emission estimates for the period. The factors are based on emission estimates and activity levels for the years 1984 to 1988 from the following data sources: Crutzen et al. (1986); Matthews et al. (1991); Lerner et al. (1988); Cicerone and Oremland (1988); IPCC (1990 and 1992); Crutzen (1991); Hogan et al. (1991); and Subak et al. (1991). The relevant data sources used in deriving the anthropo- genic activity levels for the estimation of the five anthropogenic methane emissions categories are given below. 1. Methane emissions are caused by enteric fermentation in ruminant animals, including all cattle, sheep, other livestock, wild animals, and the rest by the decomposition of animal waste. Our estimate of global emissions from all domestic cattle and sheep is about 105 Tg of methane which is in the middle of the ranges given by Crutzen et al. (1986); Lerner et al. (1988); IPOC (1990); Hogan et al. (1991); and Subak et al. (1991). The specific emissions depend on the animal populations as well as on the size of the individual animals, the amount and type of food. Our estimates are based on the animal population sizes in the 13 world regions. The livestock numbers are from selected agricultural production statistics pub- lished by FAO (19683; 1971; 1975; 1976; 1988; and 1989). 2. Main sources of energy-related methane emissions are underground coal mining, oil and gas production and natural gas transport and distribution. Most of the methane released from coal production is due to underground coal mining, ventilation of the shafts and tran- sportation to end-use. Methane leakage from pipelines and venting from oil and gas wells is the other important source. While the -84- production of fossil energy sources is known with a rather high degree of precision the actual methane emission factors are only indicative. Thus, the overall fossil energy methane emissions are not well known. Our estimates are based on the coal and natural gas primary energy consumption (including associated gas from oil production) and stem from the same sources as the estimates of carbon dioxide emissions from coal and natural gas given above in the Appendix. 3. Methane emissions from rice paddies depend on a number of fac- tors that vary regionally and annually irluding fertilization, water and crop management, growing period and paddy characteristics among others. Majority of emissions arises under wet rice cultiva- tions which represents almost 85 percent of the worldwide cultiva- tion area. Our estimates of the historical emissions are based on rice production in the 13 world regions. The implicit (and probably unrealistic) assumption is that the ratio of wet rice production to total regional production has not changed drastically since 1950. The rice production data are from selected agricultural production statistics published by FAO (1963; 1971; 1975; 1976; 1986; and 1989). 4. Methane emissions from landfills are caused by the anaerobic decay of organic wastes and are a function of municipal waste generation and disposal practices, landflling rates, types of waste material such as their average hydrocarbon conteat and conversion and out- gasing rates of methane. Our estimates of the historical emissions are based on population size in the 13 world regions between 1950 and 1988. In fact where actually measured, the methane emissions from landfills are closely correlated with levels of population and economic activities. Sources of historical population data for the 13 world regions are given below in this Appendix. 6. Methane emissions associated with land clearing, biomass burning and deforestation in general depend on many factors including the amount of biomass burnt each year in different regions by type of vegetation, fraction of wood or biomass removed and used for other purposes from the cleared areas, the kind of burning (e.g. Ramming, charcoal, smouldering, fires, etc.). The relative magni- tude of our estimates is, however, in the lower range with about 30 Tg. This is also constant with our relatively low estimates of C02 emissions from biomass burning. The estimates were derived by -85- assuming that they are proportional to carbon dioxide emissions from biotic sources such as deforestation and unsustainable biomass burning. The factor of proportionality was fixed for the period 1984 to 1988 and applied to the time series on carbon diox- ide emissions from the sources given above in this Appendix. A. Additional soclo-economic background data Population 1800-1988: Time series adapted from Fuji (1990) and complemented by estimates of Durand (1967), Demeny (1991), and Mitchell (1980; 1982; 1983) to yield the 13 region geographical breakdown of the parametric framework. 1988 adult population (over 18 years of age) are derived from UN (1990). 1989-2100: Based on World Bank population projections (Zachariah and Vu, 1988). Gross Domestic Product (GDP): 1988 data in US $ 1988 from Economist (1990). For non-convertible currencies Economist (1990) uses "compromise' exchange rates, yield- ing for instance for the former USSR a per capita GDP level of 2,055 US $, which can be considered a more realistic estimate than tradi- tional (e.g. CIA) estimates yielding up to 8819 US $ per capita (US DOC, 1991). In the report (but not yet included in the Parametric Framework) also purchasing power parity (PPP) GDP estimates were used in the comparisons. Data are derived from UNDP (1990). National per capita PPP GDP estimates were recalculated with 1987 population figures (Economist, 1990) to yield total PPP GDP, and then ted to the 13 regions used in the study. Land area Total land area data are derived from FAO (1989) Production Statis- tics. National and regional estimates were adjusted to the 13 regions of the Parametric Framework. -87- APPENDIX III. - Parametric Framework Software Appendix 1. General Information The Parametric Framework is programmed in Lotus 1-2-3 release 2.2. The computer requirements include the availability of a hard disk and at least 640 kilobytes (640K) RAM. The software package contains data for 13 world regions (see Figure 2.1 above and section on Regional Land Area below) on: land area, population, carbon dioxide and methane emissions by source. The Parametric Framework consists of six data files, a work file and a library. Numerical data are contained in the files LAND.WK1, PAST.WK1, and WB.POP.WK1. The files CON.FOSS.WK1, CON.CARB.WK1, CON.GHG.WK1, and METHANE.WK1, are used for GHG accounting and for calculating regional contributions to historical concentration increase. Finally, the major tool for calculating various GHG allocation scenarios is the spreadsheed WORKFILE.WK1 and its associated library WORKFILE.MLB. Before invoking the Parametric Framework, all of these files are to be copied to the directory from which Lotus 1-2-3 can be called and chich is recognized as default setup. All of the communication with the Parametric Framework is menu driven and done by scrolling and enter- ing the appropriate commands and/or required information. 2. Calling the Parametric Framework Lotus 1-2-3 is called form the default directory where the Parametric Framework files are stored. After calling Lotus 1-2-3, load the file WORKFILE.WK1, choose the Lotus "Add-in" menu option, load the file MACROMGR.ADN and invoke the library WORKFELE.MLB. Thereafter, all communications with the Parametric Framework are done in the WORKFILE.WK1 and are menu driven. WORKFILE.WK1 performs all of the calculations and data manipula- tions for the four allocation criteria. To move over the screen (worksheet) Just scroll up, down, left and right (note that results are also displayed beyond column "F"on the screen). The screen is updated automatically after the prompted information is changed or new parameter values (to unprotected cell ranges) are assigned. To move from one to another allocation criterion, press "ALT-F3" and type a MACRO name and press ENTER. The MACRO names refer to the four allocation criteria: ABPC for across the board percentage cuts; EERP for equal emission rights per person; CPPC for cutbacks -88- proportional to past contributions; and NCSC for natural car.on sink per capita. The results from any Parametric Framework run chn be printed and/or plotted using the standard Lotus 1-2-3 menu options. As all calculations for different criteria are performed within WORKFILE.WK1, zomparison of different scenarios is also possible using standard Lotus print and graphic features (cf. section on compar- ing model ru. below). A sample run of the Parametric Framework is given below. 3. Changing the Data Files The Parametric Framework includes a complete data set contained in the seven Lotus 1-2-3 spreadsheets. Data are disaggregated for 13 world regions. The aggregation level cannot be changed, but the data themselves can be changed and/or modified (if required, protected ranges have first to be "unprotected" by the respective Lotus option). Data include regional land area, historical population levels and future population projections, historical carbon dioxide emissions by major source and historical methane emissions. Next, a short description is given of each of the seven data files and instructions are given how the files are to be updated and stored io that they can be used by the Parametric Framework. 3.1. Regional Land Area Spreadsheet LAND.WK1 contains the data on land area of 13 regions of the world defined as follows: 1. North America (USA and Canada) 2. Western Europe (including Greece and the former GDR; excluding Yugoslavia and Turkey) 3. Eastern Europe (excluding former USSR and former GDR; including Yugoslavia) 4. USSR (ex-USSR, and Russia prior to 1917) 5. Japan 6. Oceania (Australia and New Zealand) 7. China (mainland only) 8. India 9. Rest of Asia (excluding Middle East countries, China, India; includ- ing Mongolia, Afghanistan, Pakistan, Korea (North and South), and remaining Indian Ocean and Pacific Asian countries. 10. North Africa and Middle East ("NAME`, including Turkey) -89- 11. Rest of Africa (Africa outside North Africa) 12. Brazil 13. Rest of Latin America (Latin America excluding Brazil) DEVELOPED COUNTRIES (regions 1 to 6) LESS DEVELOPED COUNTRIES (regions 7 to 13) WORLD The regional disaggregation cannot be changed within the Parametric Framework, however data can be changed and/or modified by invoking Lotus 1-2-3 and loading LAND.WK1. The file has to be saved under the same name so that it can be used by the Parametric Framework. 3.2. Future Population Projections WB.POP.WK1 contains population projections (source: World Bank) in millions for the 13 regions of the Parametric Framework for the period 1989 to 2100. For changing values, load, modify and save WB.POP.WK1 for subsequent use of alternative future population data by the program. 3.3. Historical Data PAST.WK1 contains historical time series of population in millions from 1800 to 1988; carbon dioxide emissions in gigatons of carbon from 1800 to 1988 disaggregated into industrial sources and biota; and methane emissions in teragrams of methane from 1950 to 1988. The data can be changed and/or modified by invoking Lotus 1-2-3 and load- ing PAST.WK1. In order to be used by the Parametric Framework, the file has to be saved under the same name and then the following files have to be retrieved and saved in consecutive order: . CON.CARB.WK1, CON..FOSS.WK1, METHANE.WK1, CON-GHG.WK1. 3.4. GHG Equivalences PAST.WK1 also calculates aggregated historical time series required by the Parametric Framework - total carbon dioxide emissions and total carbon dioxide and methane emissions (i.e. total greenhouse gases emissions) by summing, the relevant subcategories for each year. The latter are calculated using a methane to carbon dioxide equivalence fac- tor on a mass basis. The assumed default value is 21. Following the convention of the Parametric Framework, aggregated GHG emissions -go- are expressed as tons carbon-equivalent (to convert to tons C02- equivalent multiply by 3.66). The methane equivalence factor can be changed into any other appropriate value, but it must be loaded into the Parametric Framework by first saving the PAST.WK1 file under the same name and then loading and saving CON-GHG.WK1. 3.5. Atmospheric Concentrations The spreadsheet CON.FOSS.WK1 calculates regional contributions to atmospheric carbon concentrations due to industrial sources of carbon dioxide (including fossil energy, cement production and gas flaring) and CON.CARB.WK1 calculates regional contributions to atmospheric carbon concentrations due to total carbon dioxide emissions (including also biota sources of C02). In both cases the contributions to atmos- pheric concentrations are calculated using an ocean uptake constant for the following time intervals: 1800-1970, 1800-1971, ... , 1800-1988. Default value for the ocean uptake constant is assumed to be 300 years. To change the value, load spreadsheet CON.CARB.WK1, make changes and save under the same name and then retrieve spreadsheet CON.YOSS.WK1 (the new value will appear on the screen) and save under the same name. The spreadsheet METHANE.WK1 calculates regional contributions to the methane concentrations from emissions over the period 1950 to 1988 which remain currently in the atmosphere. This spreadsheet cal- culates intermediate numbers, using a methane decay constant. Its default value is assumed to be 25 percent per a year of the (remaining) emitted quantity, corresponding to an average atmospheric residence time of methane of about 10 years. To change the value, load spreadsheet METHANE.WK1, change the value and save the file under the same name and then retrieve CON-GHG.WKI (saving it under the same name). CON.GHG.WK1 calculates regional contributions to atmospheric car- bon equivalent concentrations due to both carbon dioxide and methane emissions. Regional contributions are calculated for the following time intervals: 1800-1970, 1800-1971, ... , 1800-1988. Carbon dioxide and methane concentrations are calculated individually as explained in the two preceding paragraphs and are then added using the methane to cLrbon dioxide equivalence factor on a mass basis. To change the equivalence factor see section on GHG Equivalences above. To change the long-term ocean uptake constant for C02 see section Atmospheric Concentrations above. * 91 - 4. Comparing Model Runs Different model runs can be compared from the data, all stored in WORKFILE.WKI. After running individual scenarios with consistent defnitions of reference and target year, type of GHGs considered, and global emission target values results can be further processed using standard Lotus print and graphics options. Prespecified graphics help the visualization of the results of individual model runs and to compare different allocation criteria. To this end WORKFILE.WK1 contains the following graphics, to be invoked by the "name and "use" options of the Lotus graphics menu. Resulting regionalized emission allocation between the chosen base year and target year can be compared on absolute (..ABS) and on a per capita (.PCP) basis. Graphic CL..1..ABS and C.L1 PCP show absolute and per capita regional allocations for criterion 1 (across the board percentage cuts). Graphics for the other criteria are set up identically: C 2 ABS and CL..2 PCP for equal emission rights per person, CR..3.ABS and fL.. PCP for cutbacks proportional to past contributions, and CR..4..ABS and CRL..4PCP for natural sink adjusted emissions. Comparison of 1988 emissions and target year allocations between different criteria (ABPC, CPPC, EERP) are shown on the graphics ABS..CRIT and PCP-CRIT on absolute and per capita basis respec- tively. -92- 5. A Sample Run of the Parametric Framework A EZ 1 CARSON EMISSION MODEL: Nodel uses fottowing parameters: 2 scean Uptake Constant (T, lears)..........................: 300 3 Methane Rmovat from the Atmosphere (decay per year).....: 25.00% 4 Carbon Equivalent Factor of Nethene.......................: 21 5 If you want to change pareaeters, toed, make changes and then 6 save again following spreadsheets (in consecutive order): 7 past.wki, can,carb.wkl, can foss.ki, mathane.wki, cn ghg.wki. A I - C 0 1F 120 121 .*********************************************************************** 122 Define current model by using MACRO: press *ALT*F3#, then type: 123 Across the Board Percentage Cuts.......................... APC 124 Equal Emission Rights per Mead of Population................0: EEP 125 Cutbacks Proportional to Past Co tribution..................: CPPC 126 Natural Carbon Sink per Capits...........................#: NCSC 127 If MACRO does not work, you have to load and odd-in (se options of the 128 Lotus 123 menu) to the memory progre MACRONGW.ADM (provided with Lotus 129 123 software), then activate progra and toad library LORKFILE.NLB. 131 132 Velcome to the environ;ont of scenario #1: 133 ACROSS THE BOARD PERCENTAGE CUTS, UITN SENSITIVITY ANALYSIS FOR CHOICE 134 OF BASE YEAR (to return to the esa press "ALT*F30, then type NMENUN) 135 Define base and target years: BASE PRESENT TARGET % DECAY IS DEFINED 136 Define in colums 8 and 0: 1985 1988 2050 FOR THE PERIOD 13? a base year from the range ************.************* PRESENT..TARGET 138 1970..1988; a target year from the range 1989..2100. Please also specify 139 .************************ wabat kind of data you went to e in the 140 The workspace is below.- column F (INFO) just for information: type 141 Use arrow keys to move.- 01 in the column F for the data of your 142 You can also took at the-- choice and u0 for all other ones: 143 the sane scenario #1 in- Regional Land Size, TKM2 .........: 0 144 per capita terms in the- 1988 Regional Population, mins...: 0 145 coluns G..J. 1988 Regional Adult Popul., mtns.: 1 146 Please do not forget that- Regional 1988 GOP, ains $ ........ 0 147 you can put "1 only in- 1988 Fossil Fuel Emissions, Gt C.: 0 148 one cell in the colum F,- 1988 Total C02 Emissions, Gt C...: 0 149 otherwise you may receive- 1988 OGG Emissions, Gt C equiv...: 0 150 a wrong number in the cell- 1988 Population Density, 000/Ka2.: 0 151 F160: workspace is below.- 1988 GUG/Land, t/Km2............: 0 152 Please do not forget that- 1988 Fossil Fuel per Capita, t C.: 0 153 you can put u1" only in-- 1988 Total C02 per Capita, t C...t 0 154 one cel I in the coluan F,- 1988 ONG per Capita, t C equiv...: 0 155 otherwise you may receive- 1988 Fossil/Adult Capita, t C ....: 0 156 a wrong nuber in the cell- 1988 Total C02/Adult Capita, t C.: 0 157 F160.- - 1988 GIG/Adutt Capita, t C e%.uiv.: 0 158 You can put. "1" only In- 1988 Fossil/CDP, Kg C/1988 S ..... 0 159 one cell in the column F.- 1988 Total CO2/GDP, Kg C/1988 $..: 0 160 The workspace is below.- 1988 GNO/GDP, Kg C equiv./1988 S.: 0 161 162 -------*************************- ********************- **************** 163 Define the type of Greenhouse Gas: type "10 in the colum F for 164 the Greenhouse Gas you currently work with, and type 0 for 165 all other ones. WARNINGI You can put *1" only in one cell. 166 Fossil Fuels and Industry Carbon Dioxide Emissions........: 0 167 Total C02 Emission (Fossil Fuels, Industry and Biota) .....: 0 168 Total GHG Emissions (Carbon Dioxide and Nethane) ..........: 1 169 ********************--****************--***************-*-***--****-*** 170 Define emissions in target year as 2 of emissions in ref. year: 49.24% 171 **-**---*-*****-*************-********--*-***-**********--***-********** 172 REGIONS EMISSION, Gt C ANNUAL 173 1985 1988 2050 % DECAY INFO 174 -------********- ********************- ****- ******- **********- ****- ***** 175 North Aera...........9:1.523194 1.640520 0.750020 -1.25% 210.109 176 Western Europe...........027420 0.998494 0.505901 -1.09% 294.138 177 Eastern Europe..........:0.40913 0.416638 0.201481 -1.16% 91.608 178 USSR ....................:1.169931 1.276643 0.576074 -1.28% 208.529 179 Japan...................:0.275273 0.290202 0.135544 1.22% 94.516 180 Oceania.................:0.102588 0.109683 0.050514 -1.24% 14.405 181 China ...................:.828379 0.918007 0.407893 -1.30% 732.602 182 India...................0.382911 0.411972 0.188545 -1.25% 465.486 183 Rest of Asia............:0.789934 0.575672 0.388963 -0.63% 434.401 184 North Africa & kid. East:0.272597 0.295806 0.134226 -1.27% 163.282 185 Rest of Africa..........:0.4517 0.416193 0.235523 -0.91% 248.332 186 Brazil ...................:0.287963 0.300735 0.141793 *1.21% 85.813 187 Rest of Latin Anerica...:0.516694 0.473722 0.254420 *1.002 161.29 188 DEVELOPED COUNTRIES......:4.507590 4.732181 2.219537 -1.21% 189 LESS DEVELOPED COUNTRIES:3.556798 3.392109 1.751367 -1.06% 190 ORLD...................:8.064389 8.124291 3.970905 -1.15% 192 The end of the workspace. To return to the manu press "ALT-F30, then typ 193 -4. A a C D E F 205 Welcome to the environment of scenario #t 206 EQUAL EMISSION RIGHTS PER HEAD OF PRESENT (OR FUTURE) POPULATION 207 (to return to the menu press NALT*F30, then type "MENU) 208 Define base and target years: BASE PRESENT TARGET % DECAY IS DEFINED 209 Define in coluass S and D: 1985 1966 2050 FOR THE PERIOD 210 a base year from the range *****......***.---.**. PRESENT..TARGET 211 1970..1988; a target year from the range 1989..2100. Please also specify 212 .*********..***.*********** what kind of data you went to se in the 213 The workspace is below.- column F (INFO) just for information: tyF% 214 Use arrow keys to move.- #1" in the column F for the date of your 215 You can also ook at the- choice and "0" for alt other ones: 216 the same scenario #1 in-- Regional Land Size TKat .........: 0 217 per capita terms in the-- 1988 Regional Population, mIns...: 0 218 colums G..J. 1988 Regional Adult Poput., mlns.: 1 219 Please do not forget that- Regional 1988 GDP, stns S ........: 0 220 you can put UtW only in- 1988 Fossil Fuel Emissions, Gt C.: 0 221 one cell in the colum F,- 1988 Total C02 Emissions, Gt C...: 0 222 otherwise you may receive- 1988 0G Emfs3ions, Gt C equiv...: 0 223 a wrong nurber in the cell- 1988 Population Density, 000/Ka2.: 0 224 F160: workspace is below.- 1988 GRG/Land, Mt/Km2............: 0 225 Please do not forget that- 1988 Fossil Fuel per Capita, t C.: 0 226 you can put "I" only in- 1988 Total C02 per Capita, t C...: 0 227 one cell in the colum F,- 1988 GRG per Capita, t C equiv...: 0 228 otherwise you may receive- 1988 Fossit/Adult Capita, t C....: 0 229 a wrong number in the cell- 1988 Total C02/Adult Capita, t C.: 0 230 F160. ------ 1988 GHG/Adult Capita, t C equiv.: 0 231 You can put "1 only in- 1988 Fossit/GDP, Kg C/1988 S .....: 0 232 one cell in the colum F.- 1988 Total C02/GDP, Kg C/1988 S..: 0 233 The workspace is below.- 1988 GHG/GDP, Kg C equfv./1988 S.: 0 234 235 ************************-****-*******-********-****-*-*-********-***-*-- 236 Define the type of Greenhouse Gas: type "1" in the column F for 237 the Greenhouse Gas you currently work with, and type "O" for 238 all other ones. UARNINGI You can put "" only I one cel. 239 Fossil Fuels and Industry Carbon Dioxide Emissions........: 0 240 Total C02 Emission (Fossil Fuels Industry and giot) .....: 0 241 Total GG Emissions (Carbon Dioxide and Methane) ..........: 1 242 ****.---**-- *********- *-- **- **-- ** ************- **- *****- ***- **- *** 243 REGIONS EMISSION PER CAPITA, t C ANNUAL 244 Define: 0246 only 1985 1988 2050 % DECAY INFO 245 -****************-***-***-*****-************-**-**-*-******-*--***-*-*** 246 North America...........:5.78327 6.063112 0.4192 -4.22%5.292564 247 Western Europe..........:2.699014 2.616741 0.4192 -2.91%2.221669 248 Eastern Europe..........:3.653422 3.653897 0.4192 -3.43%3.166278 249 USSR ....................:4.226410 4.498531 0.4192 -3.765.826584 250 Japan...................:2.290983 2.366815 0.4192 -2.75%2.200141 251 Oceania.................:5.399402 5.581462 0.4192 *4.0953.685588 252 China ...................:0.796250 0.846105 0.4192 -1.13%0.562138 253 Indi...................:0.50042 0.507815 0.4192 -0.31%0.215273 254 Rest of Asia............:1.9232 0.747279 0.4192 -0.93%0.608834 255 North Africa & Mid. East:0.899957 0.899723 0.4192 *1.22%0.734442 256 Rest of Africa..........:1.099075 0.869844 0.4192 -1.17%0.571842 257 Brazi..................:2.124191 2.086149 0.4192 -2.56%1.528038 258 Rest of Latin America...:1.942974 1.685072 0.4192 *2.2251.267536 259 DEVELOPED COUNTRIES.....:3.846025 3.969128 0.4192 -3.56% 260 LESS DEVELOPED COUTRIES:0.970122 0.869965 0.4192 -1.17% 261 ORLD....................1.666763 1.595695 0.4192 -2.135 262 *- - - - - - -- - - - - - -- - - - - - -- - - - - -------*-** *-** * ** * * * ** * * *-** * ** * * * *** --* -----* 263 The end of the workspace. To return to the menu press "ALT-F3*, then typ 264 - 95 - A 8 C 0 E F 276 Welcome to the environsent of scenario #3: CUTBACKS PROPORTIONAL TO 277 PAST CONTRIBUTIONS TO CONCENTRATION INCREASE ON A REGION BASIS 278 (to return to the menu press *ALT*F3", then type "MENU") 279 Define base and target years: BASE PRESENT TARGET % DECAY IS DEFINED 280 Define in coluns 8 and D: 1985 1988 2050 FOR THE PERIOD 281 a base year from the range **********R*************** PRESENT..TARGET 282 1970..1988; a target year from range 1989..2100. To run this scenario, 283 -***-**y********o********** you have to specify also absolute emission 284 The work:pace is below.- level in target year for the World total 285 Use arrow keys to move.- (def ine in the bottom cell of the colum D 286 You can also took at the- of the workspace below). In the colum F 287 the sane scenario #3 in- you can always see regional contributions 288 per capita terms in the- to atmospheric carbon concentration due to 289 coluns G..J. the missions of the Greenhouse gas you 290 currently work with. 291 ************.************** -************* ----------- * *---- **** 292 Define the type of Greenhouse Gas: type " in the colum F for 293 the Greenhouse Gas you currently work wfth, and type NO" for 294 all other ones. WARNINGI You can put "01 only in one cell. 295 Fossil Fuels and Industry Carbon Dioxide Emissions ........ 0 296 Carbon Dioxide Emission (Fossil Fuels, Industry and Siota): 0 297 Total GHG Emissions (Carbon Dioxide and Methane)..........: 1 298 ***. ****-***---*****--*****-***********-*********--*****-*******-*---*** 299 Caution: negative emissions in colum 0 mean that reduction below 0 300 emissions is required, i.e. the region has a net emission deficit in a 301 target year. Error message in the column E Indicates that exponential 302 % decay is not defined for negative emissions. 303 --*-*******--*-***-********-*******-*************-*****-**- ---******--* 304 REGIONS EMISSION, Gt C ANNUAL 305 Define: 0322 only. 1985 1988 2050 % DECAY INFO 306 **********************--*-*****-******************-***---****----*----** 307 North America...........:1.523194 1.640520 0.418436 -2.18% 29.63% 308 Western Europe..........:1.027420 0.998494 0.315335 -1.84% 16.56% 309 Eastern Europe..........:0.409183 0.416638 0.225145 -0.99% 4.64% 310 USSR ....................:1.169931 1.276643 0.775978 -0.80% 12.14% 311 Japan...................:0.275273 0.290202 0.201213 -0.59% 2.16% 312 Oceania.................:0.102588 0.109683 0.029260 -2.11% 1.95% 313 China ...................:0.828379 0.918007 0.667581 -0.51% 6.07% 314 India...................:0.382911 0.411972 0.209712 -1.08% 4.90% 315 Rest of Asia............:0.789934 0.575672 0.363141 -0.74% 5.15% 316 North Africa & Mid. East:0.272597 0.295806 0.228552 -0.42% 1.63% 317 Rest of Africa..........:0.4717 0.416193 0.198866 -1.18% 5.27% 318 Brazi ..................:0.287963 0.300735 0.166071 -0.95% 3.27% 319 Rest of Latin America...:0.516694 0.473722 0.200703 -1.38% 6.62% 320 DEVELOPED COUNTRIES...:4.507590 4.732181 1.965370 -1.41% 67.09% 321 LESS DEVELOPED COUNTRIES:3.556798 3.392109 2.034629 -0.82% 32.91% 322 WORLD...................:8.064389 8.124291 4 *1.14% 100.00% 323 ***---******--*********-*-*--*-***---*-----**------------------*-------- 324 The end of the workspace. To return to the menu press "ALT-F3", then typ 325 A S C 0 E F 337 Welcome to the environment of scenario #4: EQUAL EMISSION RIGHTS PER 338 CAPITA FOR EMISSIONS EQUIVALENT TO NATURAL CARBON SINKS, UNIFORM 339 CUTBACKS OF EMISSIONS CURRENTLY EXCEEDING THESE LEVELS. 340 (to return to the menu press NALT*F3", then type "MENU*) 341 Define base and target years: BASE PRESENT TARGET % DECAY IS DEFINED 342 Define in colums B and D: 1985 1988 2050 FOR THE PERIOD 343 a base year from the range *************************** PRESENT..TARGET 344 1970..1988; a target year from range 1989..2100. In the column 0 natural 345 ****************b*o***n**** carbon sink in the reference year is given 346 The workspace is below.- on per capita basis for the target year. 347 Use arrow keys to move.- In the colum F you can always see regional 348 You can also took at the- population for the target year of your 349 the same scenario #4 in- choice. 350 absolute terms in the- 351 coluns G..J.- 352 353 ********** ********* ***.****** ******- ** **- ***- *- ************-*- **** 354 Define the type of Greenhouse Gas: type #1 in the column F for 355 Greenhouse Gas you currently work with, and type "00 for all 356 other ones. WARNINGI You can put #10 only in one cett. 357 Fossil Fuels and Industry Carbon Dioxide Emissions........ 0 358 Carbon Dioxide Emission (Fossil Fuels, Industry and Bfota): 0 359 Total GHG Emissions (Carbon Dioxide and Methane)..........: 1 360 ***. *****-*----*-* ****************** **********-- *- **- *-- ********- *- ** 361 Total level of emissions, you currently work with, in the reference 362 year..................... 1985 is, Gt C..................:8.064389 363 Define natural carbon sink in the reference year, Gt C........: 4 364 (usually sink is assumed to be approximately about 50% of emissions; 365 the rest is the airborn fraction). 366 --- *--- -------- **********************************************- ****** 367 REGIONS EMISSION PER CAPITA, t C ANNUAL 368 Define: F363 only 1985 1988 2050 % DECAY INFO 369 --- * *- - --**- **--- *****************- **- ************************* 370 North America ...........:5.783297 6.063112 0.419173 -4.22%309.9531 371 Western Europe..........:2.699014 2.616741 0.419173 -2.91%371.3646 372 Eastern Europe..........:3.653422 3.653897 0.419173 -3.43%133.2022 373 USS R....................:4.226410 4.498331 0.419173 -3.76W363.2212 374 Japan...................:2.2903 2.366815 0.419173 -2.75%126.2901 375 Oceania.................:5.399402 5.581462 0.419173 -4.09%24.33513 376 Chin.......... ........:0.796250 0.846105 0.419173 -1.13%1638.934 377 India...................:0.500442 0.507815 0.419173 -0.31%1527.840 378 Rest of Asia............:1.095232 0.747279 0.419173 -0.93%1666.280 379 North Africa & Mid. East:0.899957 0.899723 0.419173 -1.22%875.9147 380 Rest of Africa..........:1.099075 0.869844 0.419173 *1.17%1674.618 381 Brazil..................:2.124191 2.086149 0.419173 -2.56%269.7288 382 Rest of Latin America...:1.942974 1.685072 0.419173 -2.22%560.9025 383 DEVELOPED COUNTRIES.....:3.846025 3.969128 0.419173 -3.56%1328.366 384 LESS DEVELOPED COUNTRIES:0.970122 0.869965 0.419173 *1.17%8214.220 385 WORLD...................:1.66763 1.595695 0.419173 -2.13%9542.586 386 - ************- ***************- **************- ********************** 387 The end of the workspace. To return to the mu press #ALT-F3", then typ 388