Table 19. U.S. Methane Emissions from Enteric Fermentation
in Domesticated Animals, 1990-1998
(Million Metric Tons of Methane)
| Animal Type | 1990 | 1991 | 1992 | 1993 | 1994 | 1995 | 1996 | 1997 | P1998 |
| Cattle | 4.88 | 5.01 | 5.11 | 5.19 | 5.35 | 5.36 | 5.22 | 5.17 | 5.16 |
| Sheep | 0.15 | 0.15 | 0.14 | 0.14 | 0.13 | 0.12 | 0.11 | 0.10 | 0.10 |
| Pigs | 0.08 | 0.09 | 0.09 | 0.09 | 0.09 | 0.09 | 0.08 | 0.09 | 0.09 |
| Goats | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 |
| Horses | 0.04 | 0.04 | 0.04 | 0.04 | 0.04 | 0.04 | 0.04 | 0.04 | 0.05 |
| Total | 5.17 | 5.30 | 5.39 | 5.47 | 5.62 | 5.62 | 5.47 | 5.42 | 5.41 |
| P = preliminary data. Notes: Data in this table are revised from the data contained in the previous EIA report, Emissions of Greenhouse Gases in the United States 1997, DOE/EIA-0573(97) (Washington, DC, October 1998). Totals may not equal sum of components due to independent rounding. Sources: Cattle, sheep, and pig population data provided by the U.S. Department of Agriculture, National Agricultural Statistics Service, Livestock, Dairy and Poultry Service. Goat and horse population figures extrapolated from U.S. Department of Commerce, Bureau of the Census, Census of Agriculture, 1982, 1987, and 1992. Emissions calculations based on U.S. Environmental Protection Agency, Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-1997, EPA-236-R-99-003 (Washington, DC, April 1999), pp. 159-161, web site www.epa.gov/globalwarming/inventory/1999-inv.html; and P.J. Crutzen, I. Aselmann, and W.S. Seiler, "Methane Production by Domestic Animals, Wild Ruminants, Other Herbivorous Fauna, and Humans," Tellus, Vol. 38B (1986), pp. 271-284. |
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