Belching cows have become an increasingly familiar symbol of global warming, at least among the hyper-involved. In the popular consciousness, livestock isn't a problem, but all told, belching cattle and the land cleared to let them graze accounts for 18% of the world's greenhouse gas emissions -- more than the entire transportation sector.
First, a little biology lesson, courtesy of the Los Angeles Times, which explains how cows produce methane, a potent greenhouse gas:
Cows and other ruminants have four stomachs, the first of which, called the rumen, is where the trouble lies; bacteria in the rumen produce methane. Scientists -- mostly in Australia, New Zealand and Britain, where the problem is taken a lot more seriously than it is here -- are working on a variety of technical solutions, including a kind of bovine Alka-Seltzer. Scientists are also trying to develop new varieties of feed grasses that are more energy efficient and thus generate less methane, and they are experimenting with targeted breeding to produce a less-gassy strain of cattle.
On the other end, researchers are also exploring ways to store livestock waste so it doesn't produce so much methane and nitrous oxide, another even more potent greenhouse gas.
As consumers, we can all do a small part by eating less meat. For more on that, see The 1 Hamburger a Day Global Warming Solution.
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