Power plants remain the largest stationary source of greenhouse gas emissions with 2,221 million metric tons carbon dioxide equivalent (mmtCO2e), which equals about one-third of total U.S. emissions.
The U.S. Environmental Protection Agency posted the second year of GHG emissions data on its website February 5. The information, which shows GHG emissions in 2011, allows public access to emissions data by sector, greenhouse gas and geographic region.
Emissions from power plants were down about 4.6 percent from 2010 to 2011, however, which the EPA states reflects an ongoing increase in power generation from natural gas and renewable energy sources.
Petroleum and natural gas systems were the second largest sector for GHG emissions at 225 mmtCO2e in 2011, and refineries were the third-largest emitting source with 182 mmtCO2e. The emissions from refineries were up 0.5 percent from 2010, and this is the first year of reporting for petroleum and natural gas systems.
The 2011 data is collected through the congressionally mandated Greenhouse Gas Reporting Program and includes information from facilities in 41 source categories that emit large quantities of greenhouse gasses. The 2011 data also contains new data collected from 12 additional source categories, including petroleum and natural gas systems and coal mines.