WASHINGTON, DC — Energy-related carbon dioxide emissions in the U.S. dropped a record 7 percent in 2009, the largest decline in more than 60 years as the country encountered an economic recession, a cleaner energy supply and made gains in efficiency.

The Energy Information Administration said this week that CO2 emissions fell more steeply than the decline in Gross Domestic Product, suggesting that factors other than the economy were playing a greater role in the emissions data.

Those factors include improved fuel economy that contributed to a drop in petroleum demand; the U.S. fleet inched up to 28.5 miles per gallon in 2009, compared to 27 mpg the year before, the EIA said in the report, "U.S. Carbon Dioxide Emissions in 2009: A Retrospective Review."

Fuel switching from coal to natural gas helped drive the carbon intensity of the electric power sector lower in 2009. Between 2008 and 2009, the cost of coal rose 6.8 percent, while natural gas declined 48 percent on a per Btu basis, the EIA said. Meanwhile, growth in renewable energy sources continued to displace fossil fuel generation. The EIA pointed out that between 2000 and 2009, wind generation increased a whopping 11-fold, making it the second largest source of renewable energy behind hydropower. The agency estimates this helped the U.S. avoid about 39 million metric tons of emissions in 2009.  

Short-term emissions trends will depend largely on how the various sectors recover from the recession, the EIA warned.

"If energy-intensive industries lead the economic recovery, emissions would increase faster than if service industries or light manufacturing play the leading role," the EIA said in the report. "If coal, which was more heavily impacted by the recent economic downturn than other energy sources, rebounds disproportionately, the carbon intensity of the energy supply could rise above the 2009 level."

Long-term trends, however, point to continued declines in both the energy intensity of the economy and carbon intensity of the fuel supply. Carbon dioxide represents some 80 percent of total greenhouse gas emissions in the U.S.

U.S. President has committed the country to a 17 percent drop in greenhouse gas emissions by 2020, based on 2005 levels.

The release of the report comes as news surfaces in China pointing to growth in energy demand. The New York Times reported Thursday the country's carbon intensity grew 3.2 percent in the first quarter, which will make it harder for China to achieve a 2010 goal of improving carbon intensity 20 percent, based on 2005 levels.

China, the world's top emitter, plans to reduce carbon intensity by between 40 percent and 45 percent by 2020.

Image CC licensed by Flickr user Schristia.