Six main greenhouse gasses were tracked – CO2, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. The report stated that the increase in emissions in 2007 was due primarily to an increase in CO2 associated with fuel and electricity consumption.

Additional information on the greenhouse gas inventory report can be found at http://epa.gov/climatechange/emissions/usinventoryreport.html.