Greenhouse gases rise, EPA reports

Annual U.S. greenhouse gas emissions rose 0.8% in 2005, according to an EPA report released last week. Total U.S. emissions of the six main greenhouse gases in 2005 were equivalent to 7,260 million metric tons of carbon dioxide. These gases include carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. EPA notes that while emissions have grown by 16% from 1990 to 2005, the U.S. economy grew by 55% over the same period. The agency attributed the 2005 increase to greater demand for electricity due to summer heat and economic growth. CO₂ makes up around 75% of all greenhouse gas emissions, which are weighted by global warming potential for comparison purposes. Some 2,429 million metric tons of greenhouse gases were produced by electric power plants, mostly coal-fired units; 2,008 metric tons were generated by transportation; and industry produced about 1,352 metric tons. The report is available at www.epa.gov/climatechange/emissions.