Energy demand across the United States fell in 2008, leading to the largest annual decline in energy-related carbon dioxide emissions since the federal government began annual reporting on greenhouse gas emissions in 1990.
Record-high oil prices and a decline in economic activity in the second half of the year resulted in a decrease of energy-related carbon dioxide emissions of 2.8 percent last year, according to preliminary estimates issued Wednesday by the federal Energy Information Administration.
Energy-related carbon dioxide emissions account for more than 80 percent of U.S. greenhouse gas emissions. These emissions decreased from 5,967 million metric tons of carbon dioxide in 2007 to 5,802 MMTCO2 in 2008, the EIA reported.
The economy, as measured by Gross Domestic Product, GDP, grew by 1.1 percent in 2008, even taking into account the economic downturn at the end of the year, but energy demand declined by 2.2 percent, indicating that energy intensity - energy use per unit of GDP - fell by 3.3 percent in 2008, the agency said.
Carbon dioxide intensity - carbon dioxide emission per unit of GDP - fell by about 3.8 percent, the EIA estimates. Oil-related emissions declined by six percent, accounting for the bulk of overall reduction in energy-related carbon dioxide emissions. Coal emissions decreased by 1.1 percent, while natural gas emissions increased by 1.0 percent, EIA data shows.
Total U.S. energy-related carbon dioxide emissions have grown by 15.9 percent since 1990, about one percent a year. As a whole, the electric power sector is the largest single source of U.S. carbon dioxide emissions, responsible for about 41 percent of total emissions.
In 2008, emissions from the electric power sector decreased by 2.1 percent, while power generation decreased by 1.0 percent. EIA says the decrease in the emissions intensity of generation of 1.1 percent in 2008 reflected an increase in wind-powered generation.
From 1990 to 2008, the carbon dioxide intensity of the economy fell by 29.3 percent or 1.9 percent per year. From 1990 to 2007, the latest year of data for all greenhouse gases, carbon dioxide intensity had fallen by 26.4 percent and emissions of total greenhouse gases per dollar of GDP had fallen by 28.0 percent.
The Energy Information Administration says it will continue to refine its estimates of 2008 carbon dioxide emissions as more complete energy data become available.
A full inventory of all U.S. greenhouse gas emissions in 2008 to be issued in late 2009 will include updated energy data and provide a further analysis of trends.
The preliminary estimates are on EIA's website at: http://www.eia.doe.gov/oiaf/1605/flash/flash.html