Though emissions from buildings grew slightly, total U.S. carbon dioxide emissions from fossil fuels decreased by a record amount in 2008, a byproduct of surging oil prices and a sagging economy, according to preliminary estimates released by the Energy Information Administration (EIA).
Carbon dioxide emissions from fossil fuels decreased by 2.8 percent in 2008, from 5,967 million metric tons of carbon dioxide (MMTCO2) in 2007 to 5,802 MMTCO2 in 2008, according to EIA, the largest annual decline in energy-related carbon dioxide emissions since EIA began annual reporting on greenhouse gas emissions.
The economy, as measured by Gross Domestic Product (GDP), grew by 1.1 percent in 2008, notwithstanding the economic downturn at the end of the year. Energy demand declined by 2.2 percent indicating that energy intensity (energy use per unit of GDP) fell by 3.3 percent in 2008. Carbon dioxide intensity (carbon dioxide emission per unit of GDP) fell by about 3.8 percent.
The economy, as measured by Gross Domestic Product (GDP), grew by 1.1 percent in 2008, notwithstanding the economic downturn at the end of the year. Energy demand declined by 2.2 percent indicating that energy intensity (energy use per unit of GDP) fell by 3.3 percent in 2008. Carbon dioxide intensity (carbon dioxide emission per unit of GDP) fell by about 3.8 percent.
Factors that influenced the emissions decrease included record-high oil prices and a decline in economic activity in the second half of the year. Oil-related emissions declined by 6 percent, accounting for the bulk of overall reduction in energy-related carbon dioxide emissions.
Total U.S. energy-related carbon dioxide emissions have grown by 15.9 percent since 1990. Energy-related carbon dioxide emissions account for over 80 percent of U.S. greenhouse gas emissions.
Preliminary fossil fuel consumption data for 2008 indicate that:
• Transportation-related emissions, which account for about a third of total energy-related carbon dioxide emissions, decreased by 5.2 percent in 2008. Since 1990 the next largest yearly decline in the transportation sector was 1.3 percent in 1991. Only one other year in the 1990 to 2008 time period experienced a decline – 1.2 percent in 2001.
• Carbon dioxide emissions from the residential sector declined by 1.1 percent in 2008. Heating degree-days rose by 5.6 percent, but the summer was also cooler than 2007 and cooling degree-days fell by 8.7 percent, which helped to offset the increase in heating-related energy demand.
• The commercial sector, which includes all non-residential, non-industrial buildings, such as stores, office buildings, schools, hospitals, and government buildings, experienced an emissions increase of 0.5 percent in 2008.
• Industrial carbon dioxide emissions fell by 3.2 percent in 2008, continuing a trend of falling industrial sector emissions since 2004. In addition to manufacturing, the industrial sector includes agriculture, construction and mining.
When electric power sector emissions are considered as a whole rather than being allocated to the end-use sectors that consume electricity, they are the largest single source of U.S. carbon dioxide emissions, representing about 41 percent of total emissions. In 2008, emissions from the electric power sector decreased by about 50 MMTCO2 or 2.1 percent, while power generation decreased by 1.0 percent. The decrease in the emissions intensity of generation of 1.1 percent in 2008 reflected, among other factors, 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.
EIA 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.
