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Every time a cow burps or passes gas, a little puff of methane wafts into the atmosphere.
Each of those puffs coming out of a cow’s plumbing, added together, can have a big effect on climate because methane is a potent greenhouse gas—about 28 times more powerful than carbon dioxide at warming the Earth, on a 100-year timescale, and more than 80 times more powerful over 20 years. The effects aren’t just hypothetical: Since the Industrial Revolution, methane concentrations in the atmosphere have more than doubled, and about 20 percent of the warming the planet has experienced can be attributed to the gas.
There's not that much methane in the atmosphere—about 1,800 parts per billion, about as much as two cups of water inside a swimming pool. That’s about 200 times less concentrated in the atmosphere than carbon dioxide, the most abundant and dangerous of the greenhouse gases. But methane’s chemical shape is remarkably effective at trapping heat, which means that adding just a little more methane to the atmosphere can have big impacts on how much, and how quickly,...
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