Since emissions actually declined in 2001 and grew at moderate rates in both 2002 and 2003, the emissions still remain below 2000 levels, but they are about 16 percent higher than 1990 emissions. EIA attributes the growth in 2003 to a number of factors, including increased heating demand during a cold winter, an increase in the number of U.S. homes, increased energy use in the commercial sector, and a shift in electric generation from natural gas to coal and oil, which emit more carbon.
Carbon dioxide emissions account for more than 80 percent of U.S. greenhouse gas emissions, and are a good indicator of trends in total emissions. In October, the EIA will release a full inventory of greenhouse gas emissions in 2003.