Dung Beetles and Global Warming

By: Jeremiah Asaka

As a young boy growing up in a livestock-rearing community in the Lake Victoria region, dung beetles fascinated me. I used to wonder why of all the things in this world, rolling cow dung was dung beetles’ favourite hobby. It was only later that I learnt that dung beetles actually feed on dung and use the dung rolls as egg-laying grounds.

And who thought dung beetles could ever even come close to saving the world from the effect of global warming? Well, by the mere fact that they feed on others’ waste, they are already performing a vital ecological role—vital enough to make the world a better place to live in (See an African Dung Beetles at work).

Closely related to this role, a recent study conducted by researchers at the University of Helsinki has connected dung beetles to the battle against global warming.

Approximately 2.6 billion people, 40 percent of the world’s population, depend on agriculture for their livelihood. But as far as global warming goes, agriculture is a major contributor to greenhouse gas. The livestock industry alone contributes about a third of global emissions of methane, a gas that makes up half of farming’s contribution and is even more potent than the much-maligned CO2.  

Against such a backdrop, researchers at the University of Helsinki conducted a study to examine the impact of dung beetle activities on the amount of methane produced by decomposing cow dung. They compared the amount of methane released from a dung beetle-free sample and a dung beetle-infested sample. Their study revealed that the test sample that was exposed to dung beetle activity produced 40 percent less methane over a summer period than did the dung beetle-free sample.

The beetles’ magic comes about as they dig and turn the cow dung. Methane is produced in environments with little or no oxygen by bacteria that feast on decomposing organic matter, such as grasses and wood. So as the beetles dig and turn the dung they aerate it and subsequently change conditions so that less methane is produced. The ultimate effect is less methane released into the atmosphere.

The foregoing makes the dung beetles look like instant heroes. But another dimension of the study sheds more light on the reality of the situation. The study further revealed that the presence of the beetles in aging cowpats increased the release of another greenhouse gas, nitrous oxide.  This is counterproductive to say the least. Scientists do not know how counterproductive it is yet, but it will be a great basis on which to design future studies aimed at investigating the effect of dung beetles’ activity on dung green house gas emission.

This beetle story reminds me of an idea I picked in a sustainability class at the Voinovich School last year. The idea was that planet Earth functions as a socioecological system where all components are linked through some sort of a feedback mechanism. As complex as life on Earth may seem, it is all interlinked. The action of the beetles on the cow dung, for example, has an effect on the well-being of human society directly through reduction in the amount of cow dung on fields and, indirectly through the effect their action has on the emission of global warming-causing gasses.

Therefore, the moral of the beetle story is that we need to live on Earth knowing that we share it with others who are not necessarily human. Who our unchecked actions may be deleterious to, generating feedback that ends up jeopardizing our very own peaceful and fulfilling existence here on Earth.

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