Open AccessInventory of methane emissions from U.S. cattle
Author(s) -
Westberg H.,
Lamb B.,
Johnson K. A.,
Huyler M.
Publication year - 2001
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2000jd900808
Subject(s) - methane , greenhouse gas , environmental science , livestock , beef cattle , dairy cattle , agriculture , zoology , emission inventory , methane emissions , environmental protection , agricultural science , agronomy , geography , biology , air quality index , forestry , ecology
Many countries, including the United States, are in the process of inventorying greenhouse gas emissions as a prerequisite for designing control strategies. We have developed a measurement‐based inventory of methane emissions from cattle in the United States. Methane emission factors were established for the major livestock groups using an internal tracer method. The groups studied included cows, replacement heifers, slaughter cattle, calves, and bulls in the beef sector and cows plus replacement heifers in the dairy industry. Since methane emission is dependent on the quality and quantity of feed, diets were chosen that are representative of the feed regimes utilized by producers in the United States. Regional cattle populations, obtained from U.S. Department of Agriculture statistics, were combined with the methane emission factors to yield regional emission estimates. The methane totals from the five regions were then summed to give a U.S. inventory of cattle emissions for 1990, 1992, 1994, 1996, and 1998. Annual releases ranged from 6.50 Tg in 1990 to a high of 6.98 Tg in 1996. On a regional scale the North Central region of the United States had the largest methane emissions from livestock followed by the South Central and the West. The beef cow group released the most methane (∼2.5 Tg yr −1 ) followed by slaughter cattle (∼1.7 Tg yr −1 ) and dairy cows at about 1.5 Tg yr −1 . Methane released by cattle in the United States contributes about 11% of the global cattle source.