U.S. Greenhouse Gas Emissions by Gas
In 2009, the United States emitted over 6.5 billion metric tons of greenhouse gases (CO2E). Carbon dioxide accounted for the largest percentage of greenhouse gases (83%), followed by methane (10%), nitrous oxide (5%), and other greenhouse gases (2%). Total U.S. emissions for 2009 totaled 6,633 tons of CO2E and net emissions, taking sinks into account, totaled 5,618 tons CO2E.
Source: Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2009 (EPA 2011)







