Human-caused Emissions are Main Cause to Rise in Atmospheric Methane

A new paper published in National Science Review by ESSIC/AOSC scientist Zhen Zhang highlights the role of anthropogenic activities in driving the growth of atmospheric methane concentrations since 2007.


In the study, the scientists use a comprehensive ensemble of CH4 source estimates and isotopic δ13C-CH4 source signature data to show that the resumption of CH4 growth is most likely due to increased anthropogenic emissions. Their emission scenarios suggest that the agriculture, landfill, and waste sectors were responsible for 53 ± 13% of the renewed growth over the period 2007–2017 compared to 2000–2006; industrial fossil fuel sources explained an additional 34 ± 24%, and wetland sources contributed the least at 13 ± 9%. This finding improves the understanding of causes of the changes in atmospheric CH4 over the past 25 years, enabling the development of more targeted mitigation strategies and policies to stabilize and ultimately reduce key contributing emission sectors. The study also suggests the need for wetland measurements to better constrain the contemporary and future role of wetlands in the rise of atmospheric methane and climate feedbacks. 


Zhen joined Earth System Science Interdisciplinary Center (ESSIC), University of Maryland in 2021. His research focuses on understanding the global methane cycle at local to global scales and in response to climate, anthropogenic activities, disturbance, and land-use change. His research includes hydrological modeling and remote sensing for surface water dynamics and biogeochemical modeling for wetland methane fluxes with land surface models, in particular dynamic global vegetation models.


Click here to access the article: “Anthropogenic emissions are the main contribution to the rise of atmospheric methane (1993-2017)“.