This is the largest percentage decline in total U.S. GHG emissions since 1990, the starting year for EIA's data on total GHG emissions.
Total U.S. greenhouse gas emissions were 6,576 million metric tons carbon dioxide equivalent (MMTCO2e) in 2009,
a decrease of 5.8 percent from the 2008 level, according to EIA report, "Emissions of Greenhouse Gases in the United States 2009."
"The large decline in emissions in 2009 was driven by the economic downturn, combined with an ongoing trend toward a less energy-intensive economy and a decrease in the carbon-intensity of the energy supply," said EIA Administrator Richard Newell.
Emissions of energy-related carbon dioxide decreased by 7.1 percent in 2009, having risen at an average annual rate of 0.8 percent per year from 1990 to 2008.
Among the factors that influenced the emissions decrease was a decline in Gross Domestic Product of 2.6 percent.
Methane emissions increased by 0.9 percent, while nitrous oxide emissions fell by 1.7 percent in 2009.
For the full report: www.eia.gov/environment/emissions/ghg_report/