Climate change is widely understood to be driven by the air pollution that results from burning fossil fuels. While fossil fuel emissions account for most forms of air pollution, there also exists several natural sources of air pollution. For example, cattle are well known for contributing to climate change by releasing digestive gas that is rich in methane. Methane is a greenhouse gas that is 30 times more potent than carbon dioxide. Surprisingly, termites emit far more methane into the atmosphere than cows. This is due, in part, to termite abundance, but the unique wood-digesting bacteria in termite guts is the primary reason for the relatively methane-rich digestive gas emitted by the insects. Experts estimate that termites are responsible for 1 to 3 percent of all methane emissions. This seemingly insignificant amount actually equals 20 million tons of methane. However, the amount of methane emitted by termites may be less significant than previously thought, as researchers have recently learned that termite nesting mounds contain bacterial microorganisms that absorb the methane gas released by termites.
Considering that mounds contain entire colonies that are composed of thousands of individual termites, methane emissions are particularly thick and concentrated around mounds. Since mounds are methane hotspots, Dr. Philipp Nauer from the School of Ecosystem and Forest Sciences at the University of Melbourne measured methane emissions within mounds to gain a more accurate idea of how much methane is released into the atmosphere.
Dr. Nauer did not expect to discover methane-consuming bacteria within termite mound-soil. This group of soil bacteria are known as methanotrophs, and they consume methane gas as their primary energy source. The researchers measured the amount of methane consumed by methanotrophs in 29 mounds from 3 termite species. It turns out that 50 percent of the methane released by termites within a mound is consumed by the bacteria. The methods Dr. Nauer developed for measuring the amount of gas that is released by termite mounds, and the amount of gas consumed by methanotrophs within mounds can also be used to measure termite population size within each mound.
Do you think that some forms of termite activity could be environmentally harmful despite the fact that termites are an ecologically essential insect species?
