"Sweetening cow breath is a matter of some urgency, climate scientists say. Cows have digestive bacteria in their stomachs that cause them to belch methane, the second-most-significant heat-trapping emission associated with global warming after carbon dioxide. Although it is far less common in the atmosphere than carbon dioxide, it has 20 times the heat-trapping ability.
Frank Mitloehner, a University of California, Davis, professor who places cows in air-tight tent enclosures and measures what he calls their “eruptions,” says the average cow expels — through burps mostly, but some flatulence — 200 to 400 pounds of methane a year.
More broadly, with worldwide production of milk and beef expected to double in the next 30 years, the United Nations has called livestock one of the most serious near-term threats to the global climate."
Another big source of methane that many don't bring up too often is rice farming. I wonder if Monsanto would consider working on new methane-free genetically engineered strain. That may not be a bad idea if they aren't doing it already.
