New research published recently in the Proceedings of the National Academy of Sciences has revealed that the recent surge in methane emissions globally is driven predominantly by microbes in the environment rather than by fossil fuels, as was previously believed. These findings are crucial for developing effective strategies to mitigate methane emissions and combat climate change. Methane is a potent greenhouse gas that is responsible for about a third of the warming that the planet has experienced since industrialization. Despite the fact that methane makes up a smaller portion of the atmosphere compared to carbon dioxide, it is much more effective at trapping heat, making it a significant target for addressing climate change.
According to the study, methane concentrations in the atmosphere have nearly tripled since the 1700s. Unlike carbon dioxide, which can linger in the atmosphere for thousands of years, methane degrades within a decade. Therefore, reducing methane emissions can have an immediate and powerful impact on slowing the rate of warming. The researchers emphasize that cutting down on fossil fuel consumption remains critical for addressing climate change, but reducing food waste and consuming less red meat can also help lower one’s methane footprint. Microbial sources, such as wetlands, cattle, and landfills, account for more than half of global methane emissions, with archaea playing a key role in methane production as they break down organic matter.
Collaborating with the Global Monitoring Laboratory at the National Oceanic and Atmospheric Administration (NOAA), researchers have been analyzing air samples from around the world to identify the sources of methane emissions. By examining the isotopic composition of methane samples, the team can distinguish between methane from fossil fuels, which contains more carbon-13 isotopes, and methane from microbial sources, which has lower carbon-13 levels. Since 1998, the lab has been measuring methane isotopes to track emissions. The researchers observed a significant increase in atmospheric methane levels since 2007, with microbial sources driving most of the increase in methane emissions starting in 2020.
Despite prior studies attributing methane growth primarily to human activities like fossil fuel production, the isotopic analysis conducted in this study reveals that microbial sources are the main culprits behind the recent surge in methane emissions. However, it is unclear whether these microbial emissions are coming from natural sources, such as wetlands, or human-driven sources like landfills and agriculture. Further investigation is planned to pinpoint the exact sources of the increased methane emissions. In a warming world, microbial emissions could intensify, contributing to accelerated global warming. Addressing the climate crisis requires not only reducing methane emissions but also tackling CO2 emissions to mitigate the impact of these greenhouse gases on the environment.
