SMART NEWS

Dung Beetles Offset Climate Change

Even the most determined dung beetles can’t offset all of those emissions, so don’t feel too relieved about that steak or burger

Rachel Nuwer

August 30, 2013

Methane, a gas that significantly contributes to global warming, comes from an array of sources associated with digestion and decay—like landfills, bogs, and the digestive tracks of the world’s cows. ”Cattle-rearing,” according to the UN News Center, “generates more global warming greenhouse gases, as measured in CO2 equivalent, than transportation.”

An unexpected hero has emerged to help contain this messy predicament, however. Dung beetles, it turns out, keep cow pats fluffy and aerated, preventing methane—which requires oxygen-free conditions—from forming. In a new study, researchers used a closed chamber to measure gaseous emissions from cow paddies both with and without beetles. The beetles, they found, significantly lowered the amount of greenhouse gases that seeped out of the cows’ waste.

“If the beetles can keep those methane emissions down, well then we should obviously thank them -– and make sure to include them in our calculations of overall climatic effects of dairy and beef farming,” said study lead Tomas Roslin in a statement.

One of the authors warns, however, that our appetite for beef is on the rise, while many dung beetle populations are on the decline. But most of these dung beetle declines are linked to populations of mammals in distress—think elephants, rhinos or pretty much any other large, charismatic species that people like to shoot or push out of prime habitat. Many species of dung beetles are intimately linked to their hosts through particular dung preferences, so as those big animals decline, so, too, do the bugs.

Cow farms, on the other hand, aren’t going anywhere, so as long as we don’t douse fields with pesticides, the beetles will probably be there, steadfastly munching away and helping to prevent that would-be methane from forming. But still, even the most determined dung beetles can’t offset all of those emissions, especially since a significant portion come directly out of the cow (mostly as burps). So don’t feel too relieved about eating that steak or burger.