Greenhouse gas emissions- perspectives on the top 20 emitters and developed versus developing nations

July 27, 2012, 7:55 am
Source: Crs

Using the World Resources Institute (WRI) database on greenhouse gas emissions and related data, this report examines two issues. The first issue is the separate treatment of developed and developing nations under the United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol. This distinction has been a pivotal issue affecting U.S. climate change policy. The second issue is the continuing difficulty of the current approach designed to address climate change through limiting greenhouse gas emissions to a specified percentage of baseline emissions (typically 1990). The data permit examination of alternative approaches, such as focusing on per capita emissions or the greenhouse gas emission intensity (measured as emissions per unit of economic activity). Key findings include:

  • A few countries account for most greenhouse gas emissions: in 2000, the United States led by emitting 19% of the world total, followed by China with 14%; no other country reached 6%; the top seven emitters accounted for 52% of the 185 nations’ emissions.

  • Land-use effects (e.g., deforestation) on emissions are negligible for most nations, but they cause emissions to rise sharply for certain developing nations, for example, Brazil and Indonesia.

  • While oil- and gas-producing Gulf States have the highest per capita greenhouse gas emissions, in general developed nations rank high in per capita emissions (in 2000, Australia, the United States, and Canada ranked 5, 7, and 9, respectively, in the world), while developing nations tend to rank low (China, India, and Indonesia ranked 98, 156, and 123, respectively)

  • The greenhouse intensity of the economy — the metric by which the George W. Bush Administration addressed climate change — varies substantially among developed countries (the Ukraine emits 667 tons/million international $GDP, while France emits 93 tons/million $GDP, with the United States at 192 tons/million $GDP; developing nations show less variance unless land use is taken into account.

  • The time frame adopted for defining the climate change issue and for taking actions to address greenhouse gas emissions has differential impacts on individual nations, as a result of individual resource endowments (e.g., coal versus natural gas and hydropower) and stage of economic development (e.g., conversion of forest land to agriculture occurring before or after the baseline).

Differentiating responsibilities between developed and developing nations — as the UNFCCC does — fails to focus efforts on some of the largest emitters. Moreover, many developed countries have not achieved stabilization of their emissions despite the UNFCCC. Given the wide range of situations illustrated by the data, a flexible strategy that allows each country to play to its strengths may be appropriate if diverse countries like the United States and China are ever to reach agreement.


Climate change is a global issue[1]; however, greenhouse gas emissions data on a global basis are incomplete. Some developing countries have no institutions for monitoring greenhouse gas emissions and have never reported such emissions to the United Nations Framework Convention on Climate Change (UNFCCC).[2] In a similar vein, data on individual greenhouse gases, sources, and land-use patterns vary greatly in quality. Despite shortcomings in the data, the emerging picture of emissions has implications for considering alternative policies for controlling emissions. First, the picture outlines the estimated contributions of individual countries. Second, evaluating those emissions in terms of socio-economic characteristics (e.g., population and economic activity) provides insights on the potentially divergent interests of differing groups of nations — especially concerning developed nations versus developing ones.[3]

The World Resources Institute (WRI) has compiled greenhouse gas emissions and related data from a variety of sources into a database that is available for analysis.[4] Covering 185 nations (plus a separate entry combining the members of the European Union),[5] the database includes total emissions, per capita emissions, and greenhouse gas (or carbon) intensity,[6] selected socio-economic indicators, and other measures. Emissions data for all six greenhouse gases[7] identified by the UNFCCC are available for 1990, 1995, and 2000 for both developed and non-Annex I nations, and for 2005 for developed nations only. Data for carbon dioxide (CO2) are available back to 1850 and up to 2004 for both developed and non-Annex I nations, but the effects of land use on CO2 are only available from 1950.

This report uses the data compiled by WRI to examine a pivotal and long running issue surrounding U.S. climate change policy: the appropriate roles of developed and developing countries in addressing climate change.

The UNFCCC states as its first principle in Article 3:

The Parties should protect the climate system 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.[8]

The United States has struggled with the “common but differentiated responsibilities” of developing countries and with the pledge for the developed countries to “take the lead in combating climate change....” The resulting debate concerns what actions to address greenhouse emissions should be “common” responsibilities (i.e., undertaken by all nations) and what actions should be “differentiated” (i.e., undertaken only by developed ones). Under the UNFCCC and the subsequent Kyoto Protocol, common actions include the responsibility to monitor and report emissions; differentiated actions include the commitment to reduce emissions to a 1990 baseline for designated developed nations, listed on Annex I to the UNFCCC (and hence known as Annex I nations).

Thus the UNFCCC, the Kyoto Protocol, and much of the current debate about actions to control greenhouse gas emissions focus on individual nations’ amounts of emissions. As a result, primary attention falls on current greenhouse gas emissions, past greenhouse gas emissions, and projected greenhouse gas emissions. In this context, addressing global climate change has in effect meant reducing greenhouse gas emissions — for Annex I countries. (A complicating factor is that land use activities can affect net emissions, and the Kyoto Protocol provides methods for taking land use effects into account.) For the UNFCCC, the differentiated control action was for Annex I countries to take voluntary actions to ensure that their greenhouse gas emissions in 2000 did not exceed 1990 levels.[9] For the Kyoto Protocol, the differentiated control action was for Annex I countries to control emissions to individually specified percentages of baseline emissions, averaged over the period 2008-2012.[10] Under both the UNFCCC and the Kyoto Protocol, non-Annex I nations would be exempt from these specified control requirements —although they could voluntarily join in. This split in responsibilities — with the consequent lack of greenhouse gas control requirements for major emitting non-Annex I countries — played a key role in the United States’ refusal to agree to the Kyoto Protocol.

Justifications for the differential treatment of the developed, Annex I nations compared to the developing nations are both environmentally and economically based.

  • Environmentally, the Annex I nations account for about 72% of total carbon dioxide emissions that accumulated in the atmosphere between 1950 and 2000.[11] Thus, to the extent cumulative CO2 may be contributing to global warming, the Annex I nations bear the preponderant responsibility.

  • Economically, as the UNFCCC explicitly recognizes, the development being pursued by the non-Annex I nations depends importantly on expanded use of energy, including fossil fuels, which are the main source of carbon dioxide, the dominant greenhouse gas. From this perspective, a logic for the differing treatment of the two groups is that the developed, Annex I countries can afford to control emissions because they have achieved a relatively high standard of living, while the developing nations have the right and should have the opportunity to expand energy use as necessary for their economic development.

This distinguishing of the responsibilities of the Annex I and non-Annex I nations generates crucial and interrelated tensions:

  • First, this approach means that Annex I nations pay an economic price for addressing global climate change;

  • Second, non-Annex I nations retain the opportunity to develop their economies using least-cost energy regardless of greenhouse gas  nations, developing nations — which may be competing in certain

    emissions; this in turn means that from the perspective of the Annex economic sectors — appear to be getting a free ride;
  • And third, despite investments in controls and resulting tensions between competing economies, actual global emissions will continue to rise if the increase in emissions from non-Annex I nations exceeds any decrease in emissions achieved by Annex I ones.

The intensity of these tensions that arise from focusing on emissions levels is clear when one examines emissions data (see Appendices A, B, and C). To frame this discussion, CRS focuses on the 20 individual nations that emitted the most greenhouse gases in 2000.[12] The top 20 were chosen because they represent about 70% of the estimated greenhouse gas emissions in the year 2000 (latest available data from CAIT for all six greenhouse gases). In addition, data for the 25-member[13] European Union are included, as the Kyoto Protocol allows the EU to address its greenhouse gas emission obligations collectively. In 2000, the 25-nation EU was the third-largest emitter of greenhouse gases, after the United States and China.

A Look at the Historic Data

Current (2000) and Baseline (1990) Emissions Data

A compelling fact to emerge from the database is that a few countries account for most of the emissions. Appendices A, B, and C present data concerning the top 20 greenhouse gas-emitting nations in 2000. They accounted for approximately 70% of global emissions. Excluding land use data, the United States led in emitting greenhouse gases (1,874 million metric tons of carbon equivalent, MMTCE)[14] at 19% of the total, followed by China (1,333 MMTCE) at nearly 14%. No other country reached 6% of total emissions (although the collective 25-member EU accounted for 13%); overall, only seven countries emitted 2% or more. These top seven emitters accounted for 52% of global emissions and the next 13 top emitters accounted for another 18% of emissions.

Thus one implication of these data is that greenhouse gas control in the short term depends mainly on the actions of a relatively few nations; if the top 20 emitters (or even the top 10) all acted effectively, the actions of the remaining 160-plus nations would be of little import, at least for years.

A second compelling fact about those top emitters is that they represent very different types and situations.[15] The top 20 nations include:

Developed (Annex I) nations whose emissions grew between 1990 and 2000: the United States, Japan, Canada, Italy, Australia, and
Spain (ranked 1, 5, 8, 11, 15, and 19, respectively). These six nations accounted for 28.8% of global greenhouse gas emissions in 2000.

  • Developed (Annex I) nations whose emissions declined between 1990 and 2000, largely as a result of the collapse of the Eastern European and USSR socialist economies during the decade: Russian Federation, Germany,[16] Ukraine, and Poland (ranked 3, 6, 16, and 20, respectively).[17] These four nations accounted for 10.5% of  global greenhouse gas emissions in 2000.

  • Developed (Annex I) nations with free-market economies whose emissions declined between 1990 and 2000, largely because of a combination of low population growth, modest economic growth, and the displacement of high-emitting fuels (coal) with alternatives: the United Kingdom and France (ranked 9 and 13, respectively). These two nations accounted for 3.3% of global greenhouse gas emissions in 2000.

  • Developing (non-Annex I) nations, all of whose emissions rose during the decade: China, India, Brazil, Mexico, South Korea, Indonesia, South Africa, and Iran (ranked 2, 4, 7, 10, 12, 14, 17, and 18, respectively). These eight nations accounted for 27.6% of global greenhouse gas emissions in 2000.

For the year 2000, then, 12 of the top 20 countries were Annex I countries, including 7 of the top 10 emitters. In 2000, the Annex I countries accounted for about 61% of the top-20 group’s greenhouse emissions, compared with 39% for the developing, non-Annex I countries; in 1990, the relative shares were 68% and 32%, respectively, so the developing countries have been increasing their share.

Highlighting the tension between Annex I and non-Annex I perspectives, the number one emitters of each group were the top two emitters overall: At the top was the leading developed, free-market economy, the United States; in the number-two position was the leading developing, non-Annex I country, China.[18] Combined, these two countries accounted for over one-third of total global emissions.

Longer-Term Historical Data (1950-2000)

The impact of emissions on climate change is believed to be cumulative over decades and even centuries. Thus a longer-term examination of data provides an important perspective, and is one reason for the differing treatments of the Annex I and non-Annex I nations. Available data (see Appendices A, B, and C) give emissions estimates of energy-related CO2 emissions back to 1950.[19] The period 1950-2000 represents the re-industrialization of developed countries after World War II and the emergence of some major third world countries.

This longer-term view of emissions underscores the contribution of the Annex I nations:

  • Annex I countries’ share of energy-related emissions over the half century is 79% of global emissions of carbon dioxide. The energy and materials needed to power industrialization after World War II put Russia ahead of China as the second-largest emitter over the time period.

  • The relative rankings of several developing countries, including Brazil, South Korea, Indonesia, and Iran, drop substantially using a longer historical baseline for emissions: from the 2000 rank to the 1950-2000 cumulative rank, from 7th to 18th, 12th to 19th, 14th to 27th, and 18th to 22rd, respectively.

Greenhouse gas emissions, particularly energy-related emissions, are closely tied to industrialization. As “developed” is considered by many to be synonymous with “industrialized,” it is not surprising that those countries entering the 1950-2000 period with an industrial base (even a war-damaged one) would have higher cumulative emissions than those countries that only began to industrialize during this period.

Impact of Land Use

Changes in land use can significantly affect net levels of emissions. In general, deforestation increases CO2 emissions and afforestation decreases them. However, data on land-use changes and their conversion into equivalent units of greenhouse gas emissions are even more uncertain than the emissions data. Therefore, this discussion (see Appendices A, B, and C) is at best illustrative.

Unlike the cumulative energy-related emissions data, including land use in the calculations focuses discussion on certain developing countries.

  • Land-use practices in certain developing countries, notably Brazil and Indonesia, are having the effect of substantially upping their relative emissions ranks: The ranking of their cumulative net emissions from 1950 to 2000 rise from 18th to 5th, and 27th to 4th, respectively, when land use is taken into account.

  • For Annex I nations and many non-Annex I nations, including land use has relatively little effect on their emissions, and for many their net emissions decline. Among the top 20 emitters in 2000, the impact of accounting for land use on emissions is small for Western European and North American nations, Russia, China, and India. The United States’ relative rank (as number 1) does not change when land use is taken into account, although its net emissions in 2000 drop by 110 MMTCE (nearly 6%).

What the land-use data reflect are the relatively stable land-use patterns of countries where most land-clearing and agricultural development occurred before 1950. The Western developed nations and China and India, for example, have long established agricultural practices; in contrast, Brazil and Indonesia have over the past few decades been clearing large regions of forest and jungle for timber and/or conversion to agriculture, releasing greenhouse gases (or removing sinks). In terms of the UNFCCC and the Kyoto Protocol, including land use in the equation for controlling emissions disadvantages certain countries whose exploitation of resources and development of agriculture are occurring at a particular moment in history.

Implications of Focusing on Emissions Levels for International Actions

The data on greenhouse gas emissions highlight issues of both effectiveness and fairness in the effort to address global  climate change. Differentiating responsibilities between Annex I and non-Annex I nations, as the UNFCCC has, does not focus efforts on all of the largest emitters. As Table 1 shows, the emissions of all Annex I nations currently account for just over half of 2000 emissions. Comparing 1990 to 2000 emissions, it is apparent that the share of emissions by non-Annex I nations has been growing.

Moreover, contradictory issues of fairness arise. For Annex I countries, the present scheme of controlling greenhouse gases requires them to bear essentially all the direct economic costs. For non-Annex I countries, to the extent that development is linked to increasing greenhouse gas emissions, imposing controls on them could slow their development and hold down their standards of living vis-a-vis the developed nations.

Finally, the focus on emissions levels at specific times (e.g., a baseline of 1990) has differential and arbitrary impacts on individual nations.

  • Looking at the industrialization process, to the extent that fossil fuel use is a necessary ingredient of economic development, as acknowledged by the UNFCCC, the emergence of the global climate change issue at this time effectively determines the distinction between the developed, Annex I nations and the developing, non-Annex I nations. For Annex I nations, that energy exploitation has been incorporated into their economies and is part of their baseline for considering any controls on greenhouse gases. For developing, non-Annex I nations, however, economic development will require expanded energy use, of which fossil fuels can be the least costly. Thus imposing limits on fossil energy use at this time could result in developing countries being relegated to a lower standard of living than those nations that developed earlier. 

  • Similarly, certain land-use activities, such as clearing land for agriculture and exploiting timber, affect net greenhouse gas emissions. Nations that are currently exploiting their resource endowments, such as Brazil and Indonesia, could find themselves singled out as targets for controls. Yet developed nations, like the United States and most European countries, which exploited such resources in the past, have those greenhouse gas implications embedded in their baselines.

  • Also, the focus on 1990 as a baseline means that the Eastern European and former Soviet Union nations have the advantage of reductions in emissions from their subsequent economic contractions, which will allow them room for growth. Likewise, the discovery and exploitation of North Sea gas has allowed Great Britain to back out coal and thereby reduce emissions since the baseline.

In all these cases, the time frame adopted for defining the climate change issue and for taking actions to address greenhouse gas emissions has differential impacts on individual nations, as a result of their individual resource endowments[20] and stage of economic development. The differential impacts give rise to perceived inequities. Thus the effort to find a metric for addressing greenhouse gas emissions baselines and targets that will be perceived as equitable is challenging.

Table 1. Shares of Global Emissions by the Industrialized (Annex I), Developing (non-Annex I), and Top 20 Countries
Indicator Industrialized (Annex I) Countries n=38a Developing (non-Annex I) Countries n=147 Top 20 Nations
1990 GHG Emissions (excl. land use) 53.9% 46.1% 68.9%
2000 GHG Emissions (excl. land use) 48.4% 51.6% 70.2%
2000 GHG Emissions (with land use) 39.2% 60.8% 66.3%
Cumulative Energy-Related CO2 Emissions 1950-2000 (excl. land use) 73.8% 26.2% 83.0%
Cumulative Energy-Related CO2 Emissions (with land use) 52.6% 47.4% 77.4%
Source: Climate Analysis Indicators Tool (CAIT) Version 4.0 (Washington, DC: World Resources Institute, 2008).
a Counting the European Union countries individually, excluding the EU as a collective member

Alternative Perspectives

The problems raised above prompt the question: What alternatives to controls derived from historically based emissions levels are available? Alternative metrics for taking into account greenhouse gas emissions and economic development include per capita emissions and economic intensity of emissions.[21]

Per Capita Emissions

The socioeconomic differences between the developed, Annex I nations and the developing nations lead to considerations about emissions other than simply their absolute amounts. One alternative is to consider per capita emissions: All else equal, populous nations would emit more greenhouse gases than less populated ones. On this basis, the difference between developed, Annex I countries and non-Annex I ones is apparent.

Appendix B shows that of the top 20 emitters, the highest ranked by per capita greenhouse gas emissions[22] are developed countries (Australia, United States, and Canada, ranked 5, 7, and 9, respectively). Their per capita emissions (7.1, 6.6, and 6.0 tons per person, respectively) are double the emissions of the highest-ranked developing country in the top 20 (South Korea, at 3.0), and six times that of China (1.1). The rankings for the non-Annex I countries in the top 20 emitters range from 33 (South Korea) to 156 (India), with China ranked 98. In contrast, Annex I countries range from 5 (Australia) to 49 (France), with the United States at 7. Reasons the United States, Australia, and Canada are so high on this measure include their dependence on energy-intensive transport to move people and goods around countries of large size and relatively low population density, the use of coal for power generation, and the energy requirements for resource extraction industries.

Thus, if one were considering how to control greenhouse gas emissions, one way of trying to bridge the different interests of the developed, Annex I nations and the developing ones would be to focus on per capita emissions as a way of giving each nation an equitable share of energy use. For the United States compared to the developing world, this metric could imply constraints, depending on the compliance time frame and future technological advancements. Likewise, this approach could permit most less-developed countries to increase their emissions to accommodate expanding economies.

Greenhouse Gas Intensity of Economy

Another alternative for evaluating a nation’s contribution to greenhouse gas emissions is to consider how efficiently that nation uses energy (and conducts other greenhouse gas-emitting activities) in producing goods and services. This concept is captured by green house gas intensity — or carbon intensity[23] — measured as the amount of greenhouse gases emitted per million dollars of gross domestic product, measured in international dollars (parity purchasing power) (see Appendices A, B, and C). Carbon intensity as a greenhouse gas indicator has received considerable attention since President Bush decided to use it as a benchmark for his voluntary climate change program. Also, the World Resources Institute has advocated its use as an appropriate index for developing, non-Annex I nations.[24]

A nation’s greenhouse gas intensity reflects both its resource endowment and the energy-intensiveness of its economy. In terms of energy resources, countries with rich resources in coal would tend to be higher emitters, while countries with rich resources in hydropower or natural gas would tend to be lower emitters. In terms of economic activity, countries with major heavy industry, major extractive industries, and extensive transportation systems tend to be higher emitters, while countries without these and/or dominated by service industries would tend to be lower emitters.

As noted in terms of emissions, taking into account land use sharply increases the greenhouse gas intensity of Brazil and Indonesia.
These variables do not differentiate nations simply; overall, the top 20 emitters (see Appendices A, B, and C) range widely in greenhouse gas intensity: from 667 tons per million international $GDP (Ukraine, which relies heavily on coal) to 93 tons/million international $GDP (France, which relies heavily on nuclear power for generating electricity). These are both Annex I nations; non-Annex I nations have a narrower range, from 174 tons/million international $GDP (Mexico) to 312 tons/million international $GDP (South Africa and Iran). Taking into account land use, however, jumps Brazil to 507 tons/million international $GDP (+ 145%) and Indonesia to 1,397 tons/million international $GDP (+ 510%); the next largest increase from land use is Mexico at 17%.

As a metric for considering how to control greenhouse gas emissions, intensity focuses attention on the efficient use of energy and on the use of alternatives to fossil fuels. Thus, a greenhouse gas intensity metric would reward the use of renewables, hydropower, and nuclear power in place of fossil fuels; and among fossil fuels it would reward natural gas use and penalize coal use (with oil use falling in between).

For greenhouse gas intensity, the United States ranks number 113 in the world, making this a more favorable metric than absolute emissions (the United States ranks number 1 in the world) and per capita emissions (the United States ranks number 7). (The larger the intensity ranking number, the less GHGs emitted per dollar of GDP.) Of the indicators examined here, the United States gets the most favorable results from this one. Nevertheless, in absolute terms, the United States is relatively inefficient with respect to intensity compared with Western European countries (the EU-25 would rank 154 and Japan ranks 162. In addition, the United States is less efficient than non-Annex I emitters South Korea, India, and Mexico, but it is more efficient than China, Brazil, South Africa, Indonesia, and Iran.


As stated above, the data on greenhouse gas emissions highlight issues of both effectiveness and fairness with respect to current efforts to address global climate change. Differentiating responsibilities between Annex I and non-Annex I countries fails to focus efforts on all the largest emitters. In addition, contradictory issues of fairness arise, as Annex I countries bear essentially all the direct economic costs of reducing emissions, and non-Annex I countries are granted the right to increase emissions to meet developmental needs. Finally, the focus on historical emissions as a baseline for regulation has differential and arbitrary impacts on individual nations.

The result of the UNFCCC and Kyoto Protocol’s setting emissions targets for only developed nations and focusing on returning their emissions to a specific baseline is twofold: (1) the current regime has had little effect on global emissions, and will have little effect in the near future; and (2) the largest emitters, the United States and China, have not found it in their interests to join in the international effort to a significant degree. Indeed, the United States has pulled completely out of the Kyoto process. Proponents of the Kyoto Protocol assert that although it is only a first step, it is one that must be taken.

This history of the UNFCCC and the Kyoto Protocol raises serious questions about how to develop greenhouse gas targets, time frames, and implementation strategies. With respect to targets, the UNFCCC recognized the right of developing countries to develop and the responsibility of all countries to protect the global climate. These goals of the UNFCCC suggest that if there is to be any permanent response to climate change that involves controlling greenhouse gases, then a regime that combines some measure reflecting the right of developing countries to develop, such as per capita emissions, and some measure reflecting the need to be efficient, such as carbon intensity, may be necessary to move the world toward a workable and effective climate change framework.

As shown above, globally, a target focused on per capita emissions generally rewards developing nations,[25] providing them room for economic growth, with the target’s balance between limiting emissions and permitting growth determining the individual winners and losers. For example, based on Appendix B, a target of 3 tons carbon per person would allow all the developing nations in the top 20 emitters except South Korea growth room (South Korea would be right on the line), while five developed nations (United States, Russian Federation, Germany, Canada, and Australia) would have to make cuts (and the United Kingdom would be right on the line). In contrast, a target focused on greenhouse gas intensity would have more diverse implications for developing nations. Several major developing nations produce considerably higher greenhouse gas emissions per million dollars of GDP than some developed nations. For example, China’s carbon intensity is over twice that of Japan’s (268 tons/million international $GDP versus 113). Thus a greenhouse gas intensity goal could be a counterforce to the economic development process for some countries, meaning that the winners and losers of a regime combining per capita and carbon intensity measures could be highly dynamic and contentious. Adding land-use implications would further complicate the regime, and selectively affect certain nations, especially those just now at the point of exploiting forests (notably Indonesia and Brazil).

For the United States, a regime containing some mix of per capita and greenhouse gas intensity measures[26] would likely imply a need to constrain emissions over some time frame. The U.S. greenhouse gas intensity is declining, as is the case with most nations, but the decrease currently does not completely offset increased emissions resulting from the growth of population and of the economy. The extent to which targets could translate into economic costs would depend on the other two features of the regulatory scheme: (1) time frame (specifically, whether it would accommodate technological advances in less-carbon-intensive technology or accelerated commercialization of existing low-carbon technologies such as nuclear power); (2) implementation strategy (specifically, whether it encourages least-cost solutions and development of advanced technologies).

With respect to time frame, the data indicate two things: (1) most countries that achieved a significant reduction during the 1990s did so as a result of either an economic downturn or a substantial realignment in energy policy; (2) many countries have not been able to stabilize their emissions despite the UNFCCC’s voluntary goal, much less reduce them. That failure was the impetus for the Kyoto Agreement’s prescribed reductions. Using economic contraction as an emission reduction strategy can scarcely be considered an option. Instead, the substantial development and/or deployment of less-carbon-intensive technology, improved land-management strategies, and other actions would be necessary to achieve stabilized emissions. As noted above, greenhouse gas emissions are closely tied to industrialization — a synonym for “developed.” With few exceptions, improvement in efficiency has been gradual. A permanent transformation of the global economy necessary to ensure a long-term stabilization of greenhouse gas emissions may involve a multi-stage, long-term time frame.

The difficulty in implementing the UNFCCC suggests implementation and compliance are still an open issue. The United States submitted climate action plans during the 1990s indicating it would achieve the UNFCCC goal of returning emissions to 1990 levels. It did not. There were no sanctions. Likewise, some Kyoto signatories may not achieve their reduction targets in 2008-2012. The sanctions are unclear. Given the wide range of situations illustrated by the data, a flexible strategy that permits each country to play to its strengths may make it easier for diverse countries like the United States and China to reach some acceptable agreement.

The extent of flexibility would depend on the balance between emission reductions and economic cost designed into the targets, time frame, and implementation strategy. Market-based mechanisms to reduce emissions focus on specifying either the acceptable emissions level (quantity), or compliance costs (price), and allowing the marketplace to determine the economically efficient solution for the other variable. For example, a tradeable permit program sets the amount of emissions allowable under the program (i.e., the number of permits available caps allowable emissions), while permitting the marketplace to determine what each permit will be worth. Conversely, a carbon tax sets the maximum unit (per ton of CO2) cost that one should pay for reducing emissions, while the marketplace determines how much actually gets reduced.

Hence, a major implementation question is whether one is more concerned about the possible economic cost of the program and therefore willing to accept some uncertainty about the amount of reduction received (i.e., carbon taxes), or one is more concerned about achieving a specific emission reduction level with costs handled efficiently, but not capped (i.e., tradable permits). Of course, combinations of these approaches are possible, depending on the flexibility desired.[27] The data presented here portray a very wide range of situations and conditions among the 20 top countries that represent 70% of total emissions. Significant flexibility may not only be desirable but necessary for them to reach any significant agreement.


Appendix A

Relative Ranking of 20 Top Emitters (Plus EU-25) of Greenhouse Gases Based on 2000 Greenhouse Gas Emissions

Country Annex 1 2000 Emissions 1990 Emissions 2000 Per Capita 2000 GHG Intensity Emissions w/ Land-use 1950-2000 Cumulative Energy CO2 Emissions 1950-2000 Cumulative Energy CO2 w/land-use
United States Yes 1 1 7 113 1 1 1
China No 2 2 98 80 2 3 2
European Union-25 Yesa [3]b [2] [41] [154] [3] [2] [2]
Russian Federation Yes 3 3 22 33 5 2 3
India No 4 6 156 118 6 9 13
Japan Yes 5 5 38 162 7 5 7
Germany Yes 6 4 26 150 8 4 6
Brazil No 7 9 80 106 4 18 5
Canada Yes 8 10 9 98 10 10 9
United Kingdom Yes 9 8 36 160 12 6 8
Mexico yes  10  13  72  125  11  14  16
Italy No 11 12 46 168 13 12 15
Korea (South) No 12 19 33 115 14 19 24
France Yes 13 11 49 174 16 8 12
Indonesia No 14 18 123 93 3 27 4
Australia Yes 15 15 5 77 17 15 19
Ukraine Yes 16 7 43 24 18 7 11
South Africa No  17  16  42  69  19  13  21
Iran No 18 22 67 70 21 22 31
Spain Yes 19 20 48 159 26 17 25
Poland Yes 20 14 45 87 25 11 14
Source: Climate Analysis Indicators Tool (CAIT) Version 5.0 (Washington, DC: World Resources Institute, 2008).
a European Union members, listed in Annex I, signed the Kyoto Protocol individually and, collectively, as the EU. The Protocol gave explicit authority to the original 15 member European Union to meet its obligations collectively; the EU has in effect expanded that authority as it has incorporated new members.
b The bracketed numbers would be the ranking of the EU; if the EU ranking were counted, equal and lower rankings would increase by one (e.g., Poland would rank 21st in 2000 emissions and 46th in 2000 per capita emissions, but remain at 87th in 2000 GHG intensity).

Appendix B

Emissions and Other Climate Change-Related Indicators for 20 Largest Emitters

2000 Rank Country Annex 1 2000 MMTCE 2000 % of World 1990 MMTCE 1990-2000 Difference MMTCE Difference % 2000 Per Capita GHG Emissions (tons C/person)
1 United States Yes 1,874 19.2% 1,631 243 13.0% 6.6
2 China No 1,333 13.6% 1,027 306 23.0% 1.1
[3] European Union-25 Yesa 1,296 13.2% 1,376 -80 -6.2% 2.9
3 Russian Federation Yes 521 5.3% 791 -270 -51.8% 3.6
4 India No 438 4.5% 305 133 30.4% 0.4
5 Japan Yes 373 3.8% 329 44 11.8% 2.9
6 Germany Yes 277 2.8% 332 -55 -19.9% 3.4
7 Brazil No 259 2.6% 191 68 26.3% 1.5
8 Canada Yes 186 1.9% 156 30 16.1% 6.0
9 United Kingdom Yes 179 1.8% 198 -19 -10.6% 3.0
10 Mexico No  156  1.6%  127  29  18.6%  1.6
11 Italy Yes 146 1.5% 133 13 8.9% 2.6
12 Korea (South) No 143 1.5% 78 65 45.5% 3.0
13 France Yes 142 1.4% 150 -8 -5.6% 2.4
14 Indonesia No 137 1.4% 92 45 32.8% 0.7
15 Australia Yes 135 1.4% 110 25 18.5% 7.1
16 Ukraine Yes 132 1.4% 240 -108 -81.8% 2.7
17 South Africa No  120  1.2%  101  19  15.8%  2.7
18 Iran No 115 1.2% 69 46 40.0% 1.8
19 Spain Yes 102 1.0% 78 24 23.5% 2.5
20 Poland Yes 102 1.0% 122 -20 -19.6% 2.6
Totalb     6,870 70.2% 6,260 610 8.9%  
  WORLD   9,788   9,087 701 7.2% 1.5
 Source: Climate Analysis Indicators Tool (CAIT) Version 5.0 (Washington, DC: World Resources Institute, 2008).

a The Kyoto Agreement gave explicit authority to the original 15 member European Union to meet its obligations collectively; the EU has in effect expanded that authority as it has incorporated new members. If the EU-25 were ranked in terms of its 2000 GHG emissions, it would place 3rd.
b Total is of the 20 individual nations; it does not include the European Union.

Appendix C

Additional Emissions and Other Climate Change-Related Indicators for 20 Largest Emitters

2000 Rank Country 2000 Emissions with Land-use (MMTCE) 1950-2000 Cumulative Energy CO2 Emissions (MMTCE) 1950-2000 Cumulative Energy with Land-use (MMTCE) GDP (millions of international $) 2000 GHG Intensity (tons/million intl. $GDP) 2000 GHG Intensity with Land-use (tons/million intl. $GDP)
1 United States 1,764 58,097 50,947 $9,764,800 192 181
2 China 1,320 19,306 29,925 $4,973,052 268 265
[3] European Union-25 1,290 48,016 48,188 $10,392,391 125 124
3 Russian Federation 535 21,109 24,886 $1,024,984 508 523
4 India 427 5,034 4,709 $2,402,087 182 178
5 Japan 374 10,262 11,629 $3,309,936 113 113
6 Germany 277 12,920 12,971 $2,083,421 133 133
7 Brazil 634 2,028 18,662 $1,250,607 207 507
8 Canada 203 4,759 6,176 $846,397 219 240
9 United Kingdom 178 8,126 8,120 $1,586,635 113 112
10 Mexico  183  2,559  3,732  $901,005  174  203
11 Italy 145 3,916 3,915 $1,440,921 101 101
12 Korea (South) 144 1,890 2,127 $759,111 189 189
13 France 141 5,100 5,115 $1,528,009 93 92
14 Indonesia 837 1,226 21,897 $599,011 229 1,397
15 Australia 136 2,513 2,874 $490,673 275 278
16 Ukraine 132 5,444 5,444 $198,426 667 667
17 South Africa  121  2,789  2,803  $385,636  312  314
18 Iran 117 1,626 1,780 $369,499 312 318
19 Spain 100 2,098 2,066 $898,378 114 111
20 Poland 101 4,330 4,344 $405,618 251 250
Totalb   7,869 175,132 224,122 $35,218,206    
  WORLD 11,868 211,040 297,045 $44,971,147 218 264
Source: Climate Analysis Indicators Tool (CAIT) Version 5.0 (Washington, DC: World Resources Institute, 2008).
a The Kyoto Agreement gave explicit authority to the original 15 member European Union to meet its obligations collectively; the EU has in effect expanded that authority as it has incorporated new members. If the EU-25 were ranked in terms of its 2000 GHG emissions, it would place 3rd.
b Total is of the 20 individual nations; it does not include the European Union.



  1. ^This paper does not explore the underlying science of climate change nor the question of whether action is justified. See CRS Report RL33849, Climate Change: Science and Policy Implications, by Jane Leggett, for more information.
  2. ^For the most recent developments on submissions to the UNFCCC by non-Annex 1 countries, see items/653.php.
  3. ^The UNFCCC divides nations into two groups, nations listed in Annex I (which under the Kyoto Protocol would have specified reduction targets), encompassing “developed” nations including Eastern Europe and the former Soviet Union; and non-Annex I nations (which do not have specified reduction targets), including the rest of the world.
  4. ^Called the Climate Analysis Indicators Tool (CAIT), the database uses a variety of data sources to provide information on greenhouse gas emissions, sinks, and other relevant indicators. Full documentation, along with caveats, is provided on the WRI website at [28].
  5. ^Both the individual countries of the European Union and the European Community as an entity are Parties to the Kyoto Protocol. Within the EU, the differing situations of each constituent nation have resulted in differing emissions targets and policies for each country. While this analysis focuses on the implications of individual nations’ situations, the EU nations are authorized to meet their goals collectively.
  6. ^Carbon intensity is the ratio of a country’s emissions to its gross domestic product (GDP), measured in international dollars (purchasing power parity).
  7. ^Carbon dioxide, nitrous oxide, methane, perfluorocarbons, hydrofluorocarbons, and sulfur hexafluoride.
  8. ^United Nations Framework Convention on Climate Change, Article 3.1.
  9. ^The United States and many other countries failed to meet this voluntary goal. It was this general failure that gave impetus to the Kyoto Protocol to mandate reductions.
  10. ^Generally the baseline was 1990; the individual Annex I commitments were negotiated, with the U. S. commitment — if the United States had agreed to the Kyoto Protocol — being a 7% reduction.
  11. ^Climate Analysis Indicators Tool (CAIT) Version 4.0 (Washington, DC: World Resources Institute, 2007).
  12. ^For a more general discussion of the top 25 emitters, see Kevin Baumert and Jonathan Pershing, Climate Data: Insights and Observations (Pew Center on Climate Change, December 2004).
  13. ^CAIT does include EU members Bulgaria and Romania in its EU-25 calculations. It does include Cyprus and Malta which are EU members, but not Annex I countries.
  14. ^The UNFCCC provides a methodology for calculating the greenhouse gas contributions of nations and converting them to equivalent units — Million Metric Tons of Carbon Equivalents (MMTCE).
  15. ^For a discussion of these situations, see CRS Report RL33970, Greenhouse Gas Emission Drivers: Population, Economic Development and Growth, and Energy Use, by John Blodgett and Larry Parker.
  16. ^Germany falls into this category as a result of its incorporation of East Germany. The pre-merger West Germany was of course not a centrally planned economy.
  17. ^The only change in the top 20 between 1990 and 2000 was the dropping out of Kazakhstan, whose coal-based industries collapsed; it was replaced by Iran.
  18. ^Although comparable data are not available, some believed that by 2008 China’s GHG emissions equaled, or perhaps surpassed, U.S. GHG emissions.
  19. ^As noted earlier, CAIT has data back to 1850; however, the earlier the data, the more uncertain the quality; and land-use data are only available back to 1950.
  20. ^E.g., the availability of natural gas and/or coal, and when each has been or is being exploited; or the extent of deforestation and/or afforestation, and when either has occurred.
  21. ^For other analyses bearing on this question, see CRS Report RL32762, Greenhouse Gases and Economic Development: An Empirical Approach to Defining Goals, by John Blodgett and Larry Parker; and CRS Report RL33970, Greenhouse Gas Emission Drivers: Population, Economic Development and Growth, and Energy Use, by John Blodgett and Larry Parker.
  22. ^The top four by this measure are oil- and gas-producing Gulf States.
  23. ^While the term “greenhouse gas intensity” encompasses all six greenhouse gases, the term “carbon intensity” is sometimes used identically and implicitly means “carbon equivalents intensity” and other times is used more narrowly to refer only to carbon emissions. The discussion in this analysis focuses on “greenhouse gas intensity,” unless otherwise noted (e.g., in the discussion of cumulative emissions).
  24. ^See Kevin A. Baumert, Ruchi Bhandari, and Nancy Kete, What Might A Developing Country Climate Commitment Look Like? World Resources Institute Climate Notes, May 1999.
  25. ^An exception is several Gulf States that are high emitters due to exploitation of their oil reserves.
  26. ^See CRS Report RL33970, Greenhouse Gas Emission Drivers: Population, Economic Development and Growth, and Energy Use, by John Blodgett and Larry Parker.
  27. ^See CRS Report RL33799, Global Climate Change: Design Approaches for a Greenhouse Gas Reduction Program, by Larry Parker; CRS Report RL30024, U.S. Global Climate Change Policy: Evolving Views on Cost, Competitiveness, and Comprehensiveness, by Larry Parker and John Blodgett; and CRS Report RS21067, Global Climate Change: Controlling CO2 Emissions — Cost-Limiting Safety Valves, by Larry Parker.



Disclaimer: This article is taken wholly from, or contains information that was originally published by, the Congressional Research Service. Topic editors and authors for the Encyclopedia of Earth may have edited its content or added new information. The use of information from the Congressional Research Service should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.


Note: The first version of this article was drawn from material prepared for the Congressional Research Service by Larry Parker and John Blodgett on November 28, 2008.




(2012). Greenhouse gas emissions- perspectives on the top 20 emitters and developed versus developing nations. Retrieved from


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