ScienceDaily (May 24, 2007) — U.S. carbon dioxide emissions from burning fossil fuels decreased by 1.3 percent in 2006, from 5,955 million metric tons of carbon dioxide (MMTCO2) in 2005 to 5,877 MMTCO2 in 2006, according to preliminary estimates recently released by the Energy Information Administration (EIA).
 
The economy, as measured by Gross Domestic Product (GDP), grew by 3.3 percent and energy demand fell by 0.9 percent indicating that energy intensity (energy use per unit of GDP) fell by 4.2 percent. Carbon dioxide intensity (CO2 emission per unit of GDP) fell by 4.5 percent.
 
Factors that drove emissions lower include weather conditions that reduced the demand for heating and cooling services; higher energy prices for natural gas, motor gasoline, and electricity, that reduced energy demand; and the use of a less carbon-intensive fuel mix (more natural gas and non-carbon fuels) in the generation of electricity.
 
Through 2006, total U.S. energy-related carbon dioxide emissions have grown by 17.9 percent since 1990. Energy-related carbon dioxide emissions account for over 80 percent of U.S. greenhouse gas emissions.
 
At the energy-sector level, preliminary data indicate that:

• Carbon dioxide emissions from the residential and commercial sectors decreased by 3.7 percent and 1.0 percent respectively in 2006, as heating degree-days declined by 7.4 percent, while at the same time cooling degree-days decreased by almost 1 percent.
• Industrial emissions fell by 1.2 percent in 2006. Since 2004 emissions attributable to the industrial sector have fallen by almost 4 percent despite growth in industrial output.
• Transportation-related carbon dioxide emissions, which account for about a third of total carbon dioxide emissions, decreased by 0.1 percent in 2006.
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From 1990 to 2006, the carbon dioxide intensity of the economy fell by 26.5 percent or 1.9 percent per year. By 2005 (the latest year of data for all greenhouse gases), carbon dioxide intensity had fallen by 23.1 percent and emissions of total greenhouse gases per dollar of GDP had fallen by 24.7 percent.
EIA will continue to refine its estimates of 2006 carbon dioxide emissions as more complete energy data become available. A full inventory of 2006 emissions of all greenhouse gases to be issued in November 2007 will present revised energy data and provide a further analysis of trends.
Adapted from materials provided by US Department Of Energy, EIA.