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close this bookThe Global Greenhouse Regime. Who Pays? (UNU, 1993, 382 p.)
close this folderPart I Measuring responsibility
close this folder3 Assessing emissions: five approaches compared
View the document(introduction...)
View the documentIntroduction
View the documentComprehensiveness compared
View the documentAccuracy by category
View the documentRegional and national emissions by source
View the documentConclusions
View the documentReferences
View the documentAppendix A: Estimates of greenhouse gas emissions
View the documentAppendix B: Calculating cumulative and current emissions

Regional and national emissions by source

The difference in relative emissions contribution from industrialized and developing countries is summarized in Table 3.3.

It is clear from Table 3.3 that the more current time frame and the addition of the non-energy sources increases the emphasis of emissions from developing countries. This overall pattern holds true for emissions from selected countries. Relative per capita emissions from ten countries that account for 60 per cent of current CO2 emissions from fossil fuels appear in

Table 3.3 Emissions from industrialized and developing countries (% of world total CO2 equivalent)

Emissions category Industrialized Developing
1 Cumulative CO2, energy 86 14
2 Cumulative CO2, energy and biota 68-80a 32-20
3 CO2, energy (current) 72 28
4 Partial CH4 and CO2 (current) 57 43
5 Comprehensive (current) 52-57b 48-43

a This range is based on alternate assumptions of historical land clearing rates.
b This range is calculated based only on differences between the short and longer GWPs. If CFCs are excluded from the totals, industrialized countries' emissions comprise 52 per cent of the total assuming the 100 year GWP.

Figure 3.3. The group includes the eight greatest emitters, in addition to Mexico and Nigeria.

The bars in Figure 3.3 show countries' emissions levels relative to the global mean. For example, the white bar for Germany indicates that per capita CO2 emissions from fossil fuels are three times the global per capita mean. The per capita emissions patterns illustrated fall into three general patterns:

Figure 3.3 Per capita emissions from selected countries

1 An upward slope from the bars sequenced first as cumulative emissions followed by current emissions and fossil-related CO2 followed by emissions from all greenhouse gases and sources. While the shape of curve is tentative for some countries, it is clear that emissions in the current period and emissions from biotic and agricultural sources emphasizes the contributions of these developing countries (Brazil, China, India, and Mexico).

2 The corresponding downward sloping pattern for industrialized countries is more dramatic. The scale of per capita emissions in the historic period and from fossil fuel emissions is significantly greater for these countries (Germany, UK, and USA).

3 A horizontal pattern emerges for the more recently developed countries Japan and USSR) where per capita emissions by time period is relatively constant and the biotic component minor.

Population-weighted emissions were selected as the most compelling form of comparison. A per capita emissions criterion is intuitively equitable in a spatial sense because it assesses individual responsibility regardless of political borders, although in practice the evenhandedness may be diminished because of individuals' disparate emissions release. Alternative allocators have major flaws. Per land area introduces undeserved entitlements to countries with large uncultivatable or uninhabitable regions. Per GDP is regressive in that late-developing countries tend to have high emissions levels per unit of output, as many developing economies are especially energy intensive. Several regions have advanced a population-based approach. Japan recently pledged to cap future CO2 emissions at current per capita levels. In preliminary discussions on approaches to meeting its overall CO2 stabilization goal, the European Community indicated a preference for national targets based on per capita CO2 emission levels. Analysts and scholars have also favoured the per capita approach, although with added variations and qualifications, e.g. considering cumulative population (Smith et al. 1990), weighting by adult population (Grubb et al. 1992), crediting carbon sinks on a per capita basis (Agarwal and Narain 1991) and designating an intergenerational per capita emissions allotment (Gruebler and Fujii 991).

In Figure 3.4, I compare three sets of data - greenhouse gas emissions, population, and GDP - for the selected countries. Two general patterns emerge. For the developed countries, the share of the world's total for each of the indicators forms an inverse U-shape, with the share of GDP (and UN contributions) greater than the countries' contribution to world population and emissions. For instance, Japan makes up 2 per cent of the world's population, produces 9 per cent of the global GDP, and releases only 5 per cent of annual fossil-fuel related CO2. In contrast, the pattern for developing countries, although not as pronounced, tends to be a U-shape, with relative GDP less than the other indicators. One implication of this pattern found among the ten countries examined here is that greenhouse gas intensity (GHG/GDP) is greater in developing countries relative to the corresponding ratios in developed countries than is the GHG/population ratio. Developing regions often release more CO2 (energy related) per unit of output than do developed countries (Grubb et al. 1992). In Figure 3.4, a comparison is also made with relative GDP, or purchasing power parity adjusted GDP, a newer index that attempts to adjust for differences in purchasing power in different parts of the world and for fluctuating exchange rates (Summers and Heston 988).

Figure 3.4 Socioeconomic assessments compared with GHG emissions

While analysts are already discussing ways of adjusting assessments in order to find an equitable solution and the right incentives, in practice the differences between alternate indicators such as population and adult population are often not as great as the differences between the levels of responsibility implied in the alternative emissions source categories discussed above. By way of comparison, Figure 3.4 shows that the difference between developing countries' share of the world's population versus adult population is not as great as the difference between countries' share of emissions from all greenhouse gases versus CO2 from energy only.