"Understanding where the methane is coming from helps us guide effective mitigation strategies," said Sylvia Michel, a senior research assistant at CU Boulder's Institute of Arctic and Alpine Research (INSTAAR) and a doctoral student in atmospheric sciences. "We need to know more about those emissions to understand what kind of climate future to expect."
Methane, though present in smaller quantities than carbon dioxide, is a powerful greenhouse gas. Over a 100-year period, it traps about 30 times more heat than CO2, making it a key target for climate change efforts.
"Methane concentrations in the air have almost tripled since the 1700s," explained Jianghanyang (Ben) Li, an assistant professor at CU Boulder's Department of Atmospheric and Oceanic Sciences and INSTAAR. Addressing methane emissions offers an immediate opportunity to slow down the planet's warming, Li added, as methane degrades much faster than CO2.
Despite the discovery that microbial activity has been driving the methane increase, the researchers stressed that reducing fossil fuel use remains critical for mitigating climate change. Reducing food waste and limiting red meat consumption are also cited as ways to reduce methane emissions.
Fossil fuel production accounts for about 30% of global methane emissions, but microbial sources, such as wetlands, cattle, and landfills, contribute over half. Archaea, microorganisms found in soils and animal intestines, release methane during organic matter decomposition.
Michel, Li, and their team have been collaborating with the National Oceanic and Atmospheric Administration's (NOAA) Global Monitoring Laboratory, analyzing air samples collected globally to trace the origins of methane. By studying the carbon isotopes in these samples, they identified that methane from fossil fuels contains more carbon-13 than methane from microbial sources. This isotopic analysis has been ongoing since 1998.
The researchers found that microbial emissions accounted for over 90% of the methane surge between 2020 and 2022, a period that saw the highest levels of atmospheric methane growth since record-keeping began in 1983.
Further research is needed to determine if these microbial emissions are coming from natural sources like wetlands or from human-related activities such as agriculture and landfills.
"In a warming world, it wouldn't be surprising if any of these sources emitted more methane," said Michel, noting that microbes, like humans, have faster metabolisms in warmer conditions, which could accelerate methane emissions and intensify global warming. "So we need to address the climate crisis, and that really means addressing CO2 emissions."
Research Report:Rapid shift in methane carbon isotopes suggests microbial emissions drove record high atmospheric methane growth in 2020 - 2022
Related Links
Institute of Arctic and Alpine Research
Farming Today - Suppliers and Technology
Subscribe Free To Our Daily Newsletters |
Subscribe Free To Our Daily Newsletters |