Global methane cycles in flux

摘要

Although the concentration of methane in the atmosphere nearly doubled over the past century, fluxes of this greenhouse gas seemingly leveled off during the past 20 years. In a review published in this issue of ES & T (pp 2131-2137), researchers, led by Aslam Khalil of Portland State University, model the sources and sinks of methane. They also question whether human activities will have much of an impact on future methane levels.