Gas	1990	1991	1992	1993	1994	1995	1996	1997	1998	1999
	million metric tons of carbon or carbon equivalent
Carbon dioxide	1,351	1,338	1,365	1,397	1,422	1,435	1,484	1,505	1,507	1,527
Methane	182	183	183	178	179	179	173	172	168	165
Nitrous oxide	99	101	103	103	111	106	105	104	103	103
HFCs, PFCs and SF6	24	22	24	24	25	29	33	35	40	38
Total	1,655	1,644	1,675	1,702	1,737	1,748	1,796	1,816	1,818	1,833

Source: U.S. Department of Energy, Energy Information Administration, Emissions of Greenhouse Gases in the United States, 1999, DOE/EIA-0573(99) (GPO, Washington, DC, 2000).

Notes: HFCs = Hydrofluorocarbons. PFCs = Perfluorocarbons. SF6 = Sulfur hexafluoridene. Emissions include direct and indirect effects. Data for 1998 are preliminary. Data in this table are revised from the data in the previous EIA report, Emissions of Greenhouse Gases in the United States, 1998, DOE/EIA-0573(98) (GPO, Washington, DC, 1999).

Last Updated on 1/29/01