US Energy-Related Carbon Dioxide Emissions Declined by 2.8% in 2008; Transportation-Related Emissions Down 5.2%
|Energy-related CO2 emissions declined by 2.8% in 2008. Source: EIA. Click to enlarge.|
US carbon dioxide emissions from fossil fuels decreased by 2.8% in 2008 to 5,802 million metric tons of carbon dioxide (MMTCO2), down from 5,967 MMTCO2 in 2007, according to preliminary estimates released by the Energy Information Administration (EIA). This is the largest annual decline in energy-related carbon dioxide emissions since EIA began annual reporting on greenhouse gas emissions.
Transportation-related emissions, which account for about a third of total energy-related carbon dioxide emissions, decreased by 5.2% in 2008. Since 1990 the next largest yearly decline in the transportation sector was 1.3% in 1991. Only one other year in the 1990 to 2008 time period experienced a decline: 1.2% in 2001.
|Transportation sector CO2 emissions by fuel types (1990 to 2008). Source: EIA. Click to enlarge.|
Transportation remains the largest emitter of the end-use sectors. Motor gasoline accounts for 58.7% of the sector’s CO2 emissions, followed by diesel fuel at 23.2%. Since 1990, transportation sector CO2 emissions have risen by 21.1%—an average of 1.1% per year.
Factors that influenced the overall 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%, accounting for the bulk of overall reduction in energy-related carbon dioxide emissions.
Total US energy-related carbon dioxide emissions have grown by 15.9% since 1990. Energy-related carbon dioxide emissions account for more than 80% of US greenhouse gas emissions.
Other preliminary end-use sector fossil fuel consumption data for 2008 indicate that:
Carbon dioxide emissions from the residential sector declined by 1.1% in 2008. Heating degree-days rose by 5.6%, but the summer was also cooler than 2007 and cooling degree-days fell by 8.7%, 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% in 2008.
Industrial carbon dioxide emissions fell by 3.2% 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 US carbon dioxide emissions, representing about 41% of total emissions. In 2008, emissions from the electric power sector decreased by about 50 MMTCO2 or 2.1%, while power generation decreased by 1.0%. The decrease in the emissions intensity of generation of 1.1% in 2008 reflected, among other factors, an increase in wind-powered generation.
The economy, as measured by Gross Domestic Product (GDP), grew by 1.1% in 2008, notwithstanding the economic downturn at the end of the year. Energy demand declined by 2.2% indicating that energy intensity (energy use per unit of GDP) fell by 3.3% in 2008. Carbon dioxide intensity (carbon dioxide emission per unit of GDP) fell by about 3.8%.
From 1990 to 2008, the carbon dioxide intensity of the economy fell by 29.3% or 1.9% per year. From 1990 to 2007 (the latest year of data for all greenhouse gases), carbon dioxide intensity had fallen by 26.4% and emissions of total greenhouse gases per dollar of GDP had fallen by 28.0%.
EIA will continue to refine its estimates of 2008 carbon dioxide emissions as more complete energy data become available. A full inventory of all US greenhouse gas emissions in 2008 to be issued in late 2009 will include updated energy data and provide a further analysis of trends.