“This report – the eighteenth annual report – presents the U.S. Energy Information Administration’s latest estimates of emissions for carbon dioxide, methane, nitrous oxide, and other greenhouse gases. For this report, activity data on coal and natural gas consumption and electricity sales and losses by sector were obtained from the January 2011 Monthly Energy Review (MER).
In keeping with current international practice, this report presents data on greenhouse gas emissions in million metric tons carbon dioxide equivalent. The data can be converted to carbon equivalent units by multiplying by 12/44. Data on ozone-depleting gases with high global warming potentials (high-GWP gases) are obtained directly from the U.S. Environmental Protection Agency (EPA). For this report, updated EPA values were available for hydrofluorocarbons (HFCs); however, no updates were available for perfluorocarbons (PFCs) or sulfur hexafluoride (SF6), and last year’s values are used instead. Historical data in the chapter tables are revised from the data contained in the previous Emissions of Greenhouse Gases in the United States 2008.”