Scientists find a bacteria that can 'eat' methane. But can it curb global heating?

Scientists worry that the Arctic permafrost’s thawing will unleash dangerous amounts of methane into the sky as global temperatures increase.

But a recent study has discovered a bacteria that “eats” methane, keeping the gas from entering the atmosphere in large amounts.

Methane is a potent greenhouse gas that is released from various human activities, including energy production (natural gas and petroleum systems), business, agriculture, land usage, and waste management.

Can bacteria actually reduce global warming, though?

Let’s take a closer look.

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The methane “eating” bacteria

Using a class of bacteria called methanotrophs to naturally convert methane to carbon dioxide and biomass, a team of researchers from California University Long Beach has proposed a method for eliminating methane.

All of the bacteria in this group “’eat’ methane, removing it from the air and converting part of it to cells as a source of sustainable protein,” according to the study’s lead researcher Mary E Lidstrom.

Methylotuvimicrobium buryatense 5GB1C is a strain of bacteria discovered by Lidstrom’s team that is capable of efficiently removing methane even in low concentrations. According to the experts, if adopted widely, the technique could aid in reducing global warming.

According to a study published in the journal Proceedings of the National Academy of Sciences, using this bacteria extensively could save 240 million tonnes of methane from entering the atmosphere by 2050.

This particular bacterial group typically flourishes in conditions with high methane concentrations (between 5,000 and 10,000 parts per million (ppm)). Methane concentrations in our atmosphere are typically significantly lower, at only 1.9 ppm. However, some places, like oil wells, landfills, and rice fields, produce higher amounts of roughly 500 ppm.

The strain’s high methane consumption rate, which is more than five times higher than that of other bacteria, is most likely caused by a low energy need and stronger attraction to methane, the study found.

“Bacteria that rapidly eat methane at the higher concentrations found around cattle herds, etc could make a huge contribution to cutting methane emissions, especially from tropical agriculture,” said Euan Nisbet, professor of Earth sciences at Royal Holloway, University of London, told The Guardian while speaking about the findings of the study.

“The bacteria oxidise the methane to CO2 (a much less powerful greenhouse gas) and so you can even use the exhaust to pump into greenhouses and grow tomatoes,” Nisbet added.

Lidstrom cautions, however, that any emissions-reduction measures that boost bacterial activity in natural communities could also lead to an increase in nitrous oxide (N2O) production, which has ten times the global warming potential of methane. Importantly, this bacterial methanotrophic technique does not emit nitrous oxide.

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Challenges

There will be a need for thousands of well-functioning reactors if methane-eating bacteria are to be used on a large scale.

If the technology is scaled up, there can be a few difficulties. Temperature regulation, for example, is challenging. Since bacterial development is inhibited by temperatures outside of the recommended range of 25 to 30 degrees Celsius, the researchers pointed out that both extremes of temperature can be harmful.

“The biggest barrier to implementation now is technical: we need to increase the methane treatment unit 20-fold. If we can achieve that, then the biggest barriers become investment capital and public acceptance. We believe we could have field pilots tested within three to four years, and scale up would then depend on investment capital and commercialisation,” said Lidstrom.

According to Down To Earth, to test the viability of using the technique, the researchers urged for additional field investigations. To make sure the technology is economically viable and benefits the environment, it is necessary to analyse the environmental life cycle and techno-economics of the technology, the researchers added.

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Methane emission

Due to livestock manure and gastroenteric releases, the agriculture industry is the main source of methane emissions in the atmosphere.

According to The Guardian, methane is a particularly problematic greenhouse gas because it has more than 85 times the warming potential of carbon dioxide over the first 20 years after it enters the atmosphere.

In the last 15 years, atmospheric methane has risen rapidly, reaching record levels, and now contributes at least 30 per cent of all global warming.

At Cop26 in 2021, a number of the top economies in the world decided to cooperate to lower methane emissions immediately. They do, however, keep going up.

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Solutions

While reducing emissions is the main goal of the majority of currently suggested methane mitigation strategies, this isn’t always feasible.

In order to reach climate targets, researchers emphasise the necessity of both methane removal and reduced emissions solutions.

Down to Earth quoted research from the University of Washington as saying that eliminating 0.3–1 petagrams of methane by 2050 can limit the rise in average world temperature by 0.21–0.22 degrees Celsius.

This magnitude of temperature drops is expected to have a considerable impact, especially when paired with other methods of reducing emissions.

With inputs from agencies