U.S. Research Team Tracks Main Drivers of Global Methane Rise Using Stable Isotope Analysis
A research team from the U.S. National Oceanic and Atmospheric Administration Global Monitoring Laboratory and the University of Colorado has recently traced the sources of the rapid rise in global atmospheric methane since 2007 through high-precision methane concentration measurements and carbon and hydrogen stable isotope analysis. The findings show that over the past two decades, microbial emissions have been the primary factor driving the increase in methane concentrations, while fossil fuel-related methane emissions may have remained relatively stable overall. A methane molecule consists of one carbon atom and four hydrogen atoms, and methane from different sources differs in its carbon and hydrogen isotope composition. Researchers used this chemical fingerprint to distinguish methane sources: fossil fuel methane such as natural gas typically contains a relatively higher proportion of carbon-13, while methane produced by microbial processes in wetlands, landfills, livestock, and agricultural environments has a lower carbon-13 proportion, exhibiting a "lighter" isotopic signature. The proportion of deuterium in hydrogen isotopes also varies with the way methane is formed, providing a further basis for source identification.
2026-07-31
