Greenhouse Gas Emissions: Perspectives on the Top 20 Emitters and Developed Versus Developing Nations

Larry Parker
Specialist in Energy and Environmental Policy

John Blodgett
Specialist in Environmental Policy


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), the Kyoto Protocol, and the Copenhagen Accord. This distinction has been a pivotal issue affecting U.S. climate change policy. The second issue is the difficulty of addressing 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 2005, China led by emitting 19% of the world total, followed closely by the United States with 18%; no other country reached 6%; the top eight emitters (those emitting 2% or more of total emissions) accounted for 58% 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, most notably Brazil and Indonesia. 

• While countries whose economies are dominated by oil and gas production have the highest per capita greenhouse gas emissions, in general developed nations rank high in per capita emissions (in 2005, Australia, the United States, and Canada ranked 6, 9, and 10, respectively, in the world), while developing nations tend to rank low (China, Brazil, Indonesia, and India ranked 81, 84, 117, and 148, respectively). 

• The greenhouse intensity of the economy—the metric by which the George W. Bush Administration addressed climate change, and by which China has proposed to set its objectives under the Copenhagen Accord—varies substantially among developed countries (in 2005, not accounting for land use, Ukraine emitted 512 tons/million international $GDP, while France emitted 80 tons/million $GDP, with the United States at 153 tons/million $GDP; developing nations range from the 136 (Mexico) to 372 (China). 

• 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—has failed to engage some of the largest emitters effectively. 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 necessary if diverse countries like the United States and China are ever to reach agreement. The difficulty in finding a common strategy was evidenced by the outcome of the Copenhagen meeting, which set a climate change objective of holding global warming to less than 2 degrees C but then left up to each country the choice of how to address emissions.


Date of Report: January 7, 2010
Number of Pages: 23
Order Number: RL32721
Price: $29.95

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