Heroic Scientists Want to Clean Up Cow Farts to Save the Planet

By Meg Neal on at

Most of us consider farts to be little more than a mild embarrassment. But cow farts (and burps) are a scourge upon the Earth, releasing heat-trapping methane that wreaks havoc on our climate. Now, heroic scientists want to put an end to global warming-by-flatulence once and for all.

Stopping a fellow creature from passing gas might sound cruel and unusual. But the real cruelty is allowing this collective brown cloud to go unchecked. Ruminants—cows, sheep, and goats—release about 100 million tonnes of methane each year by farting, burping, and shitting, accounting for roughly 20 per cent of global methane emissions. And with 80 times the climate warming potential of CO2 over the short term, a little extra methane can crank up the heat fast.

Science might help us solve this problem without farm animals being any the wiser. A few years back, researchers discovered that a little-known compound called 3-nitrooxypropanol (3-NOP) has a very strange effect on ruminant digestion. Adding a small amount of it to livestock feed reduces methane emissions in sheep and cattle up to 30 per cent. A study published in the Proceedings of the National Academies of Sciences reveals why.

Using laboratory assays, a team of biologists at the Spanish National Research Council has discovered exactly how 3-NOP works—by targeting and shutting off an enzyme that plays a key role in methane formation. The enzyme is released by a group of microorganisms that live inside a special stomach compartment called the rumen. A tiny amount of 3-NOP will suppress the enzyme repeatedly.

The rumen is one of the cow’s four stomachs, and it plays a critical role in digestion. It’s here that a diverse cocktail of bacteria and fungi work together to break down cellulose, the tough, fibrous compound that renders grass, leaves, and other plant matter indigestible to humans. If a food additive messed up the balance of flora inside the rumen, that could be a real problem for cows and farmers.

To investigate this possibility, the researchers added 3-NOP to mixed populations of gut microbes in the lab. While the chemical dramatically reduced growth of methanogens, it had little effect on the overall composition of gut flora, sparing the bacteria that perform the bulk of the digestion.

In fact, if anything, adding 3-NOP to livestock feed could be a good thing for farmers’ bottom lines. Methane emissions are effectively an energy loss—a portion of the feed that ruminants aren’t putting on as weight.

“We will see an increase in the efficiency of ruminant production systems as better use is made of the energy taken in in animal feed, given that methane production accounts for a loss of up to 12 per cent of the energy an animal ingests” study co-author David Yáñez said in a statement.

So, if cattle farms start to lose that nostalgic aroma in the years to come, don’t be alarmed. A farm that’s had its farts sanitised is a farm that’s helping Florida stay above water.