Learn more about greenhouse gas emissions
Posted April 17, 2008
Updated March 22, 2009
In the U.S., our energy-related activities account for three-quarters of our human-generated greenhouse gas emissions, mostly in the form of carbon dioxide emissions from burning fossil fuels. More than half the energy-related emissions come from large stationary sources such as power plants, while about a third comes from transportation. Industrial processes (such as the production of cement, steel, and aluminum), agriculture, forestry, other land use, and waste management are also important sources of greenhouse gas emissions in the United States.
For a better understanding of where greenhouse gas emissions come from, governments at the federal, state and local levels prepare emissions inventories, which track emissions from various parts of the economy such as transportation, electricity production, industry, agriculture, forestry, and other sectors. EPA publishes the official national inventory of US greenhouse gas emissions, and the latest greenhouse gas inventory shows that in 2005 the U.S. emitted over 7.2 billion metric tons of greenhouse gases (a million metric tons of CO2 equivalents (MMTCO2e) is roughly equal to the annual GHG emissions of an average U.S. power plant.) Visit the Emissions section of this site to learn more, or review the answers to some frequent emissions questions.