Every year since 1983, a small group of researchers at the US National Oceanic and Atmospheric Administration (NOAA) have taken stock of global atmospheric methane. Some 6,000 air samples are collected at 53 monitoring stations in all sorts of climates, like Algeria and Alaska, and make their way to a laboratory in Boulder, Colorado. This research reveals that global atmospheric methane has surged in recent years, sparking panic and uncertainty among the NOAA researchers and beyond.
“A lot of the current attention on methane is driven by the results from our last sampling,” says Lindsay Lan, one of the NOAA researchers in Boulder. “In 2020, we reported a record high increase in the atmosphere methane – about 15 parts per billion (ppb) per year – and that was the highest of all time, but, in 2021, we recorded 18ppb. Those are quite alarming signals to us – those emissions have already happened.”
What cannot be done
Researchers at the NOAA are worried that natural wetlands play a significant role in the emissions spike, says Lan. They were able to identify this through isotope fingerprinting: methane from natural microbial emissions has a smaller ratio of carbon 13 to carbon 12 than fossil sources. "The ratio of carbon 13 to carbon 12 shows a decreasing trend in recent years, which suggests an increase in microbial emissions," she explains.
Microbes release methane as a waste gas, and in wetlands their proliferation is thought to be behind most of the recent surge in emissions. The highest-emitting microbes are in the Amazon basin, where a wet and warming climate makes for a microbial paradise.
“If that is the case, that would indicate [the presence of] climate feedback that has been driven by long-term greenhouse gas emissions since the industrial era, and a shift in the natural balance to release more methane – something tricky our society would have little control over," says Lan. She believes the only ways to address natural emissions like those from wetlands would be to limit global warming in the first place and to focus on reducing methane emissions from human activities.
“There cannot be large-scale efforts to mitigate natural emissions without implications," she explains. "For example, we can’t think about draining off wetlands because they are important components of our ecosystem. We cannot control the weather or the increasing natural emissions, but we can account for [them] by enforcing stronger reductions for human emissions.”
Lan says that while landfills, livestock and rice paddies are technically natural sources of methane, they are sources from controllable human activity.
What can be done
Natural emissions, although surging, are still only three-quarters of anthropogenic methane’s contribution. Methane emissions from oil and gas operations alone were 70 million tonnes in 2020 – equivalent to the entire EU's CO2 emissions, according to the International Energy Agency (IEA).
Oil production accounts for 40% of oil and gas industry methane emissions, with leaks across the natural gas value chain accounting for the remaining 60%.
Even biogas processing, which was thought to be of relatively minimal risk when it came to methane emissions, is leaking massive amounts of the gas. According to researchers at Imperial College London, biogas leaks 18 million tonnes of methane annually, more than double the IEA’s previous estimates and proportionately much higher than oil and gas.
Many of these leaks are blamed on the poor design and operation of upstream fossil fuel production facilities which, if solved, would both slash emissions and reduce operational costs.
Methane emissions trap 27 times more heat than CO2 over 100 years and have contributed to at least a quarter of the world’s warming. Because the concentration of atmospheric methane is 200 times smaller than that of CO2, it would be difficult to design an apparatus to capture it from ambient air – “you would need to capture a lot of air”, explains Lan. Instead, the focus must be on limiting those emissions at the source, she says.
The IEA estimates that current technologies such as leak detection and repair, and a ban on non-emergency flaring, could curb nearly 70% of methane emissions from the oil and gas industry, with 45% prevented at no net cost due to the value of captured methane being higher than the cost of abatement.
Those estimates were made by the IEA in 2020 during a period of unusually low gas prices. Today, amidst surging gas prices globally, estimated levels of no-cost abatement would be higher still.
New technologies such as AI sensors have proven successful at detecting and preventing leaks. For example, oil and gas major BP and AI company Kelvin’s 2017 project installed sensors in the Wamsutter gas field in Wyoming, US, to relay information and pre-empt equipment failures, and saw a 74% reduction in methane leaks and a 22% reduction in operating costs within half a year.
“Continuous methane emission sensors are displacing planes and drones, the previous [and less efficient] way that people monitored methane," says Zach Supalla, CEO of Particle, an internet of things company providing energy companies with sensors that have cloud capabilities. "The technology is [...] currently being used by large oil and gas sites.”
“Due to the urgency behind efforts to manage emissions, research and development over the past decade has already armed us with much of the information we need to target methane," says Manuel Arroyo, director of industry programs at manufacturing company Emerson. "Most of these technological solutions are already in use today.”
Arroyo remains optimistic that technology can quash anthropogenic methane emissions. Digital tools can help with the scale-up of pilot projects "to shorten the time from concept to feasibility, as well as allow for iterations on design and efficiency improvements without costly, time-consuming physical modifications”.
What should be done
Atmospheric methane’s meteoric rise, despite the existence of proven solutions to manage it, suggests too much emphasis on CO2 reduction and too little on methane.
“There should be a focus shift to methane,” says Supalla. "I think there has been with the [Biden administration’s] Inflation Reduction Act, which specifically has new restrictions around methane emissions that weren’t there previously. […] Its taxes and fines are great but not high enough [...] Having fines is a good first step, but the next challenge is how methane emissions will be managed.”
The Inflation Reduction Act specifies what methane emissions will cost an emitter but not how these costs are going to be enforced. It also does not include requirements around sensors.
“If oil and gas sites don’t have sensors, how do they know if they have methane emissions?” asks Supalla. “The [US] government needs to require that companies have a sufficient volume of continuous methane monitoring sensors. Enforcement needs to happen so the oil and gas industry is scared. If they are scared, they will invest the money to reduce methane emissions.”
The US is ahead of the EU and UK in that regard. While the EU adopted a methane strategy back in 2021, it included neither a tax on emissions nor a plan to mitigate flaring or methane leaks from oil and gas imports. The UK has yet to adopt a methane strategy at all.
Some warn that a new focus on methane must not come at the expense of CO2 emissions reductions. “While methane makes up a sizeable part of overall greenhouse gas emissions, it may be unwise to shift the focus from one greenhouse gas to another,” says Arroyo. “Ideally, all gases that contribute to climate change would be addressed. Methane and carbon dioxide emissions enter the atmosphere through different means and remain in the atmosphere for different amounts of time and at different net intensities. Each will require different methods of detection and abatement.”
“There are no good arguments to suggest we should reduce methane instead of CO2 [or vice versa],” agrees Lan. “They have to go hand in hand."