U.S. Greenhouse Gas Emissions Lower in 2006

WASHINGTON, DC, April 15, 2008 (ENS) - Overall, U.S. greenhouse gas emissions were 1.1 percent lower during 2006 than the previous year, according to the latest annual report from the U.S. Environmental Protection Agency, released today.

Emitted by the burning of the fossil fuels coal, oil and gas for power, manufacturing and transportation, greenhouse gases reduce the loss of heat into space raising global temperatures.

The agency says emissions of the main climate warming gas carbon dioxide decreased in 2006 because Americans burned less fossil fuels and used less electricity than they did in 2005.

Compared to 2005, the winter of 2006 was warmer, which decreased consumption of heating fuels, and the summer was cooler, which reduced demand for electricity, the EPA said.

Fuel consumption for transportation went down because of rising fuel prices, the agency said.

And finally, the increased use of natural gas and renewables in the electric power sector also contributed to the lowering of carbon dioxide emissions.

Coal-fired power plants like this one in the coal-rich state of West Virginia, are the biggest contributors to U.S. greenhouse gas emissions. (Photo courtesy Allegheny Energy)

The report, "Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2006," is the latest in an annual set of reports that the United States submits to the Secretariat of the United Nations Framework Convention on Climate Change, which sets an overall framework for intergovernmental efforts to tackle the challenge posed by climate change.

"Each year since 1993, EPA's experts have built a comprehensive inventory of U.S. greenhouse gas emissions," said Robert Meyers, principal deputy assistant administrator for EPA's Office Air and Radiation.

"Our understanding of emission sources is paramount to combating climate change," he said.

Total emissions of the six main greenhouse gases in 2006 were equivalent to 7,054.2 million metric tons of carbon dioxide.

These gases include carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride.

The report indicates that overall emissions have grown by 14.7 percent from 1990 to 2006, while the U.S. economy has grown by 59 percent over the same period.

Burning coal produces by far the most greenhouse gas emissions, with mobile combustion such as cars and trucks responsible for the next highest amount of emissions. Burning gas in stationary power units produces is the next highest source of emissions, with burning oil in stationary power units not far behind.

The fifth highest source of emissions is direct nitrous oxide, N2O, emissions from agricultural soil management, according to the report.

EPA prepares the annual report in collaboration with experts from multiple federal agencies and after gathering comments from a broad range of stakeholders across the country.

The inventory tracks annual greenhouse gas emissions at the national level and presents historical emissions from 1990 to 2006.

The inventory also calculates carbon dioxide emissions that are removed from the atmosphere by "sinks," such as forests, vegetation and soils, which take up carbon dioxide from the air.

To view the 2006 greenhouse gas inventory report, click here.

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