Breaking news from Rasdorf, Germany: Late last month, this farming village of some 1,500 souls was literally shocked when a shed housing 90 cows spontaneously burst into flames that singed the shed's roof and the hide of one unlucky beast (who was later treated for burns). The culprit was no arsonist, but rather the hundreds of liters of potent methane gas produced inside of the cows' guts and emitted via their burping and flatulence. The gas had built up insde the shed and was ignited by a spark of static electricity.
The idea of a shed full of flammable cow farts is both disgusting and hilarious, but the problem of livestock methane production is actually far more insidious. Every year, the roughly 3.6 billion ruminants on this planet—that's cows, goats, sheep, and oxen that chew cud—emit 80 million metric tons of gas. Each day, a cow relieves itself of about 500 liters (or 132 gallons) of methane, roughly the same amount of pollution that a car produces in the same amount of time. Although methane is a destructive greenhouse gas that contributes disproportionately to climate change—its effect on the atmosphere is 21 times greater than CO2's—few people know about this serious problem.
"It just hasn't been talked about much," said William J. Ripple, a professor at Oregon State's College of Forestry. "I think most of the attention tends to be on fossil fuels and the carbon dioxide they create."
Last month, Ripple and five co-authors published a paper in Nature Journal titled "Ruminants, Climate Change, and Climate Policy," in which they wrote that livestock production is the greatest source of man-made methane. Their proposed solution is vegetarianism, or at least a big reduction in the amount of beef, lamb, and goat that we eat.
If humans could lessen their appetite for ruminant meat, the authors write, a drop in methane production wouldn't be the only benefit: If we had fewer grazing animals, then we'd need less land dedicated to feeding them. Currently, the sole purpose of 26 percent of the terrestrial surface of the planet is to feed grazers. Freeing up that land would allow the regrowth of the forests and diverse habitats that were cleared to create livestock pastures, and this would have a drastic impact on climate-warming effects, since trees absorb carbon dioxide (as much as 48 pounds of it per tree per year). A reduction in meat consumption would mean less methane and less carbon dioxide.
But asking people to cut down on their meat consumption is a "tall order," Ripple admitted. Our appetite for flesh is growing along with our population. Each year, 25 million domestic ruminants are added to the planet. So it makes sense that the majority of methane-reduction strategies being developed today try to skirt the eat-less-meat message.
In 2003, New Zealand proposed a "fart tax" that would have collected about $300 per farmer per year to be used for methane-reduction research. The proposal was so widely reviled that nearly half of all of the country's farmers signed a petition against it. About 400 of the farmers physically blocked the capital at Wellington, and plans for the tax stalled soon afterward. In 2009, a Wales-based biotech firm produced a garlic-based feed additive called Mootral that seemed to reduce cows' methane output, but that product was discontinued in 2012 when one of its primary shareholders moved to the US. And in Australia, CSIRO Livestock Industries is working on a vaccine that combats the microorganisms responsible for the methane production: creatures that dwell deep inside livestock guts and aid in digestion, releasing methane as a chemical by-product of their work.
Despite international efforts, researchers haven't figured out a reliable solution.
"As far as a magic bullet, so far I haven't seen one," Ripple said.
Ripple believes that cutting down on ruminant meat could appeal to people who are worried about a warming planet but aren't sure about what steps to take as individuals beyond buying hybrid cars or driving less often.
"There are a lot of people out there who are concerned about climate change and don't know what they can do about it," he said. "Eating less meat is one of those things they can do." It's prime time for all of us all to become vegetarians. To effect change, Ripple suggests putting the methane issue on the UN's climate change agenda, educating the scientific community about methane emissions, and creating financial incentives for meat-producing corporations to develop meat analogs and substitutes.
But on an individual level, it might be effective to think of that smelly shed in Germany the next time you go for a bite of beef. That's probably enough to put you off your feed.