Cow Farts and Belches Are Warming the Planet — but Scientists Think They've Got a Solution

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A supplement added to cow feed reduces the animal's gaseous methane emissions by nearly a third, which could be a powerful tool in the global fight against climate change, according to a new study.

"What we've found is significant — it's the first time we've shown, in industry-relevant conditions, with a good number of cows, that this compound does work," Penn State Professor of Dairy Nutrition Alexander Hristov, the study's lead researcher, told VICE News. "It decreases methane emissions 30 percent and, at the same time, doesn't negatively affect milk production, feed intakes, or fiber digestion."

Forty-eight milk-producing cows were given the supplement over 12 weeks at Penn State. The study results were published in the journal Proceedings of the National Academy of Science.

Related: You Have No Idea How Much Your Diet Impacts Climate Change

One of the most significant sources for climate changing emissions can be found in the guts of the roughly 1.5 billion cows inhabiting the planet. The animals digest food in multiple stomachs, assisted by more than 400 types of bacteria. That long process of decomposition produces a lot of methane, which is burped, farted, and shat out by the lumbering beasts day and night, day after day.

Methane is 25 times more effective at trapping heat in the atmosphere than carbon dioxide over a 100-year time scale.

Livestock account for more than a quarter of the United States' methane emissions, according to the US Environmental Protection Agency (EPA). Globally, some 14.5 percent of all greenhouse gas emissions — and 44 percent of anthropogenic methane emissions — can be traced back to the livestock industry. And the UN Food and Agriculture Organization projects methane emissions could jump 60 percent by 2030 as developing nations achieve greater prosperity and emerging middle classes turn to meat-centered diets.

That's why researchers mixed in roughly a gram of powdered 3-nitrooxypropanol, a methane inhibitor known as 3NOP developed by DSM Nutritional Products, a Dutch company that calls the additive its "Clean Cow" project. Compared to the study's control group, cows feed 3NOP not only emitted 30 percent less methane but, because the conversion to methane in their stomachs is a net caloric loss, gained 80 percent more weight.

Related: Developing Nations Are Gobbling Up More Meat — and That Could Mean More Antibiotic-Resistant Infections

There's no incentive in the U.S. right now for farmers to cut methane emissions from cattle, Hristov said, and they won't simply make the switch out of idealistic environmental concerns. Therefore, weight gain and other industry advantages will be key for the product to be adopted commercially, he said.

"Dairy cows go through phases, and they lose a lot of weight when they calf," he said. "They don't eat enough and they produce a lot of milk and lose weight. So if we can cut down the energy loss with the inhibitor, the animals will gain more body weight and recover more quickly."

Hristov added that the cows might produce more milk in early lactation and have improved reproduction.

"It's something that will convince producers to use it," he said.

The company hopes to introduce the additive commercially by 2018. But the next step is to receive US Food and Drug Administration approval, which Hristov estimated could take more than a year.

Follow Darren Ankrom on Twitter: @darrenankrom