What makes burning methane to put yet more CO2 into the atmosphere a counterintuitive climate solution is methane’s potency. A molecule of methane released from a leaky gas pipe or a belching cow can trap almost 90 times more heat over the next two decades than each molecule of CO2. And as humanity seeks to deal with its methane emissions, ‘natural’ emissions appear to be growing. Higher temperatures dry out wetlands and melt permafrost, causing bacteria in soil to convert more of their massive carbon stores to methane.
Unless, that is, we make some radical moves. Rapid change is possible because methane happens to be short-lived. Whereas CO2 lasts for over a century, much of the airborne methane breaks down within a decade. “Methane is the only greenhouse gas for which we could reduce atmospheric concentrations in a decade or two,” says Rob Jackson, an expert on methane emissions at Stanford University.
Destroying concentrated methane, such as unwanted methane from oil and gas wells, is as easy as burning it off in one of those flares that light up the night sky above refineries. Alas, many methane sources—and definitely methane already in the atmosphere—are too dilute to feasibly attack using any of today’s technologies. “It’s only present in two parts out of a million [in the air]. So it’s a classic needle in a haystack problem,” says Jackson.
Alarmed by the risk of runaway methane emissions from permafrost, Jackson and an international group of collaborators set about drawing up a research agenda to solve the methane removal problem. Their report two years ago has spurred considerable interest.
Jackson sees progress from multiple groups working to make better methane-breaking catalysts—both heat-enhanced catalysts such as Plata’s copper-enhanced zeolites, and catalysts that turn solar energy into chemical action that his own lab is collaborating on.
His photocatalysts could be built into a methane-munching device with artificial lights, says Jackson, or potentially blended into paints so that rooftops, walls and even airplanes could use the sun’s energy to moonlight as methane-busters. “Most of the work, including our own, is being done with highly energetic ultraviolet light. We need to ideally nudge that down toward the visible wavelengths that dominate the solar spectrum,” says Jackson.
Erika Reinhardt, Executive Director of Spark Climate Solutions, a nonprofit that advocates for methane destruction R&D, cites recent work on biofilters by Mary Lidstrom, a professor emeritus of both microbiology and chemical engineering who has studied methanotrophic (methane-munching) bacteria for over 40 years. In August, Lidstrom reported a bacterium that can grow on just 200 parts per million of methane—25 to 50 times lower than most methanotrophs.
Most of the emerging approaches will work better on higher concentrations of methane, and are likely to be first put to work attacking emissions sources rather than pulling the gas out of thin air. “Research on methane removal is about working our way down a concentration curve towards atmospheric levels,” says Jackson.
A prime early target is methane-rich air ventilated from coal mines and dairy barns. Reminders of their significant methane levels arrive regularly as catastrophic accidents when ventilation falls short, such as the methane explosion at a Texas dairy farm that killed 18,000 cows last April, and a Siberian coal mine explosion that killed 52 people in 2021.
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