Different fuels emit different amounts of carbon dioxide in relation to the energy they produce. To compare emissions across fuels you must compare how many pounds of CO2 are emitted per energy output – measured here in British thermal units (Btu).

Pounds of CO2 emitted per million Btu of energy for various fuels:

Natural gas	117
Liquefied petroleum gas	139
Gasoline	156
Coal (bituminous)	205
Coal (subbituminous)	213
Coal (lignite)	215
Petroleum coke	225
Coal (anthracite)	227

Of the major fossil fuels, natural gas emits the least amount of carbon dioxide on a per Btu basis. Petroleum products and coal both emit differing amounts of carbon dioxide depending on their chemistry. Liquefied petroleum gas is the least carbon-intensive of petroleum products. Petroleum coke is the most carbon-intensive petroleum product. Although anthracite coal emits the most carbon dioxide per unit of energy output, it is not currently consumed in large quantities.

Carbon dioxide emissions per million Btu for other fuels

Last reviewed: August 14, 2008

There are various ways to compare carbon dioxide emissions across countries including: total carbon dioxide emissions, carbon dioxide emissions per capita, and carbon dioxide intensity. The data below are for energy-related carbon dioxide emissions as EIA does not have comparative data for carbon dioxide emissions from industrial processes for all countries.

• Energy-related carbon dioxide emissions – In 2005, the United States emitted 5,982 million metric tons of carbon dioxide from the consumption of fossil fuels.

Million metric tons of carbon dioxide emitted in 2005:

United States	5,982 (21% of world total)
China	5,323 (19% of the world total)
Organization for Economic Cooperation and Development (OECD) Europe	4,383 (16% of world total)
World Total	28,051

• Carbon dioxide emissions per capita – In 2005, the per capita carbon dioxide emissions in the United States were 20 metric tons. Per capita carbon dioxide emissions in the United States have not varied much over time, because the rate of growth of carbon dioxide emissions has been about the same as the growth in population.

Metric tons of carbon dioxide emitted per capita in 2005:

• United States - 20
• China - 4
• OECD Europe - 8
  

• Carbon dioxide intensity – A nation’s carbon dioxide intensity is typically expressed as metric tons carbon dioxide (MTCO2) per unit of economic activity. In 2005, U.S. carbon dioxide intensity was 544 MTCO2 per million dollars of Gross Domestic Product (GDP) based on constant 2000 dollars.

Carbon dioxide intensity in 2005 expressed as MTCO2/$ million GDP (calculated using purchasing power parity) for selected region and the world:

• United States - 544
• China - 693
• OECD Europe - 383
• World Average - 494
  

International Energy Outlook 2008, Chapter 7 includes more comparisons across countries.

Last reviewed: August 14, 2008

Greenhouse gas emissions by sector in 2006:

Emissions of Greenhouse Gases in the United States, 2006 reports EIA’s latest annual emissions data.

Last reviewed: August 14, 2008

The U.S. total electricity-related emissions in 2006 were 2,481.3 million metric tons carbon dioxide equivalent (about 35% of U.S. total greenhouse gas emissions).

This includes:

• 2,459.8 million metric tons of emissions of carbon dioxide from conventional power plants and combined-heat-and-power plants
• (2,343.9 million metric tons from the electric power sector; the rest from the industrial and commercial sectors.) 

• 0.3 million metric tons carbon dioxide equivalent of methane
• 9.0 million metric tons carbon dioxide equivalent of nitrous oxide
• 12.2 million metric tons carbon dioxide equivalent of sulfur hexafluoride from leaking electricity transmission equipment where sulfur hexafluoride is used for insulation.

Emissions of Greenhouse Gases in the United States, 2006 reports EIA’s latest annual emissions data.

Last reviewed: August 14, 2008

Energy-related carbon dioxide emissions by fuel types in 2006:

• Petroleum: 2,614 million metric tons (44% of the total energy-related carbon dioxide emissions)
• Coal: 2,142 million metric tons (36%)
• Natural gas: 1,178 million metric tons (20%)

Emissions of Greenhouse Gases in the United States, 2006 reports EIA’s latest annual emissions data.

Last reviewed: August 14, 2008

No. Water vapor is the most abundant greenhouse gas, but it is the consensus of the international community that human activity has a very small effect on its concentration in the atmosphere, and therefore EIA does not estimate emissions of water vapor.

What are greenhouse gases and how much are emitted by the United States?

Last reviewed: August 14, 2008