Science: Bovine Beano

Reducing emissions from methane-spewing cows

By Ben Whitford

Illustration by Josh Cochran

Cows may look harmless, but behind Daisy’s docile exterior lies a dangerous source of climate-changing greenhouse gases. A typical cow belches or farts hundreds of liters of methane every day. That adds up to a whopping 18 percent of global emissions coming from the world’s 1.5 billion cattle. Methane is 25 times as potent a greenhouse gas as carbon dioxide, though its overall climate impact is nearly half as significant because there’s less of it in the atmosphere. But with livestock emissions predicted to double by mid-century, researchers are racing to find a bovine version of Beano. Nobody’s hit the jackpot yet, but here are some of the more promising flatulence-busting technologies.

Food Additives

Studies show that lacing cows’ feed with expensive coconut and fish oils makes the animals markedly less gassy. Now researchers are working to achieve the same effect with cheaper alternatives like sunflower seeds, molasses, and garlic.

High-Tech Grass
Irish researchers are trying to breed grass containing highlyconcentrated organic acids, which should be easier for cows to digest. The downside: For the plan to work, farmers across the world would have to replant their pastures.

Politicians in New Zealand and Estonia have tried to tax farmers for their livestock’s methane emissions, but widespread protests have led the governments to shelve the plans.

Gourmet Diets
Up to three-quarters of global livestock emissions come from animals fed on low-quality meal, which causes increased gassiness and lowers meat production. Switching cattle to a diet of grain, clover, and wild flowers could help on both fronts.

Gas Traps
Some farmers already collect lagoons of cow manure and harvest the methane given off as the dung decomposes. The gas can either be used as a fuel or burned to convert it into less harmful CO2.

Universal Vegetarianism
If everyone gave up red meat, we wouldn’t need all those cows. But this solution is unlikely to catch on. Meat-lovers scarf down more than 60 million metric tons of beef every year, and global production is expected to more than double by 2050.

Kangaroo Stomach Flora
Australia’s favorite marsupial has a plant-heavy diet but, remarkably, methane-free emissions. A stiff dose of kangaroo stomach bacteria might have the same effect in cows. By making cows’ stomach chemistry more efficient, these bugs may also boost milk and meat production.

Issue 25

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