Donald Trump, when President of the US, heavily criticised the zero-fossil-fuels lobby saying that their science wasn’t right, and to some extent, he is backed-up by a new study at University of Colorado (CU) showed that Micro-organisms growing in landfills, on agricultural land and in wetlands are contributing to skyrocketing levels of atmospheric methane, the potent greenhouse gas, and not fossil fuels.
Recent trends towards creating and preserving wetlands, increased use of landfill and expanding use of certain processes on agricultural land have been driving the recent surge in methane emissions globally, [Analysis published Oct 21 in the Proceedings of the National Academy of Sciences by Univesity of Colorado). This shows that the net zero-drive may be a material waste of economic resources.
“Understanding where the methane is coming from helps us guide effective mitigation strategies…..We need to know more about those emissions to understand what kind of climate future to expect….as Methane concentrations in the air have almost tripled since the 1700s” said Sylvia Michel, a senior research assistant at the Institute of Arctic and Alpine Research(INSTAAR) and a doctoral student in the Department of Atmospheric and Oceanic Sciences at CU.
Methane is a potent greenhouse gas responsible for about a third of the planet’s warming since industrialization because methane traps about 30 times more heat than carbon dioxide over a 100-year time frame, making it a critical target for addressing climate change.
Unlike CO2, which can stay in the atmosphere for thousands of years, methane degrades within a decade so addressing methane emissions can have an immediate and powerful impact in slowing the rate of warming, and whilst the finding suggests microbes have been emitting more methane than fossil fuels in recent years, it remains the case that reducing fossil fuel consumption remains key to addressing climate change, because of CO2’s greater long-term impact on the atmosphere, but cutting down food waste and consuming less meat can also drastically lower a methane footprint.
Previous research suggests fossil fuel production is responsible for about 30% of global methane emissions, but it is the microbial sources — such as wetlands, cattle and landfills — that are an even more significant source of methane, accounting for more than 50% of global emissions. .
Using computer simulations, the CU team modeled three different emissions scenarios to see which one would leave an isotopic signature similar to the one observed and found that between 2020 and 2022, the drastic increase in atmospheric methane was driven almost entirely by microbial sources and that since 2007, microbes have been playing an increasingly significant role in methane emissions, with their contribution surging to over 90%, starting in 2020.
“Some prior studies have suggested that human activities, especially fossil fuels, were the primary source of methane growth in recent years, but these studies failed to look at the isotope profile of methane, which tends towards a different conclusion and used an incomplete picture of global methane emissions.,” said Xin (Lindsay) Lan, a scientist at the Cooperative Institute for Research in Environmental Sciences (CIRES) at CU Boulder and NOAA. Due to the similarity between microbial emissions from natural sources like wetlands and those from human-driven sources, such as landfills and agriculture, it is not yet possible to identify the exact source of methane, but a new study hopes to do that.
“In a warming world, it isn’t surprising that these sources emit more methane, because microbes, like humans, tend to have higher and faster metabolism when warm and consequently, more methane is produced and more is likely to stay in the atmosphere to accelerate global warming” said Michel. “The long-term goal remains a reduction in CO2 emissions.”
Sylvia Englund Michel, Xin Lan, John Miller, Pieter Tans, J. Reid Clark, Hinrich Schaefer, Peter Sperlich, Gordon Brailsford, Shinji Morimoto, Heiko Moossen, Jianghanyang Li. Rapid shift in methane carbon isotopes suggests microbial emissions drove record high atmospheric methane growth in 2020–2022. Proceedings of the National Academy of Sciences, 2024; 121 (44) DOI: 10.1073/pnas.2411212121
University of Colorado at Boulder. “Microbes drove methane growth between 2020 and 2022, not fossil fuels.” ScienceDaily. ScienceDaily, 21 October 2024. www.sciencedaily.com/releases/2024/10/241021170355.htm.