Debalic wrote:
It's too bad the great, empty plains in the middle of this country aren't covered in tall grasses and home to free-roaming herds of giant, hardy, meaty animals in the countless millions.
(The problem is catching them.)
Table 1 U.S. Methane Emissions by Source (TgCO2 Equivalents) Source Category 1990 1997 1998 1999 2000 2001 2002 2003 Landfills 172.2 147.4 138.5 134.0 130.7 126.2 126.8 131.2 Natural Gas Systems 128.3 133.6 131.8 127.4 132.1 131.8 130.6 125.9 Enteric Fermentation 117.9 118.3 116.7 116.8 115.6 114.5 114.6 115.0 Coal Mining 81.9 62.6 62.8 58.9 56.2 55.6 52.4 53.8 Manure Management 31.2 36.4 38.8 38.8 38.1 38.9 39.3 39.1 Wastewater Treatment 24.8 31.7 32.6 33.6 34.3 34.7 35.8 36.8 Petroleum Systems 20.0 18.8 18.5 17.8 17.6 17.4 17.1 17.1 Rice Cultivation 7.1 7.5 7.9 8.3 7.5 7.6 6.8 6.9 Stationary Sources 7.8 7.4 6.9 7.1 7.3 6.7 6.4 6.7 Abandoned Coal Mines 6.1 8.1 7.2 7.3 7.7 6.9 6.4 6.4 Mobile Sources 4.8 4.0 3.9 3.6 3.4 3.1 2.9 2.7 Petrochemical Production 1.2 1.6 1.7 1.7 1.7 1.4 1.5 1.5 Iron and Steel 1.3 1.3 1.2 1.2 1.2 1.1 1.0 1.0 Agricultural Residue Burning 0.7 0.8 0.8 0.8 0.8 0.8 0.7 0.8 Total for U.S. 605.3 579.5 569.3 557.3 554.2 546.7 542.3 544.9 Source: US Emissions Inventory 2005: Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2003
TABLE 1. The Important Greenhouse Gases (except water vapor) U.S. Department of Energy, (October, 2000) (1) (all concentrations expressed in parts per billion) Pre-industrial baseline Natural additions Man-made additions Total (ppb) Concentration Percent of Total Carbon Dioxide (CO2) 288,000 68,520 11,880 368,400 99.438% Methane (CH4) 848 577 320 1,745 0.471% Nitrous Oxide (N2O) 285 12 15 312 0.084% Misc. gases ( CFC's, etc.) 25 0 2 27 0.007% Total 289,158 69,109 12,217 370,484 100.00%