OECD Factbook 2011-2012: Economic, Environmental and Social Statistics
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branch Environment
branch Air and land
    branch Emissions of Carbon Dioxide

Carbon dioxide (CO2) makes up the largest share of greenhouse gases. The addition of man-made greenhouse gases to the atmosphere disturbs the earth's radiative balance (i.e. the balance between the solar energy that the earth absorbs and radiates back into space). This is leading to an increase in the earth's surface temperature and to related effects on climate, sea level and world agriculture.


The table refers to emissions of CO2 from burning oil, coal and natural gas for energy use. Carbon dioxide also enters the atmosphere from burning wood and waste materials and from some industrial processes such as cement production. However, emissions of CO2 from these other sources are a relatively small part of global emissions, and are not included in the statistics shown here. The Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories provide a fuller, technical definition of how CO2 emissions have been estimated for this table.


These emissions estimates are affected by the quality of the underlying energy data. For example, some countries, both OECD and non-OECD, have trouble reporting information on bunker fuels and incorrectly define bunkers as fuel used abroad by their own ships and planes. Since emissions from bunkers are excluded from the national totals, this affects the comparability of the estimates across countries. On the other hand, since these estimates have been made using the same method and emission factors for all countries, in general, the comparability across countries is quite good.

These data are preliminary and differ slightly from those published in the 2011 edition of the CO2 Emissions from Fuel Combustion.


Global emissions of carbon dioxide have risen by 106%, or on average 1.9% per year, since 1971. In 1971, the current OECD countries were responsible for 67% of the world CO2 emissions. As a consequence of rapidly rising emissions in the developing world, the OECD contribution to the total fell to 42% in 2009. By far, the largest increases in non-OECD countries occurred in Asia, where China's emissions of CO2 from fuel combustion have risen by 5.8% per annum between 1971 and 2009. The use of coal in China increased the levels of CO2 emissions by 5.0 billion tonnes over the 38 years to 2009.

Two significant downturns in OECD CO2 emissions occurred following the oil shocks of the mid-1970s and early 1980s. Emissions from the economies in transition declined over the last decade, helping to offset the OECD increases between 1990 and the present. However, this decline did not stabilise global emissions as emissions in developing countries continued to grow. With the economic crisis in 2008-09, world CO2 emissions declined by 1.5% in 2009. However, early indicators suggest that growth in CO2 emissions rebounded in 2010. 

Disaggregating the emissions estimates shows substantial variations within individual sectors. Between 1971 and 2009, the combined share of electricity and heat generation and transport shifted from one-half to two-thirds of the total. The share of fossil fuels in overall emissions changed slightly during the period. The weight of coal in global emissions has remained at approximately 40% since the early 1970s, while the share of natural gas increased from 15% in 1971 to 20% in 2009. The share of oil decreased from 49% to 37%. Fuel switching and the increasing use of non-fossil energy sources reduced the CO2/total primary energy supply (TPES) ratio by 6% over the past 38 years.



Further information
Analytical publications
Statistical publications
Methodological publications
Online databases
Indicator in PDF Acrobat PDF page

CO2 emissions from fuel combustion
    Table in Excel

World CO emissions from fuel combustion, by region Figure in Excel
World CO emissions from fuel combustion, by region

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