Methane, a potent greenhouse gas, ranks second only to carbon dioxide in its impact on global warming. It is primarily generated by human activities, including the decomposition of organic waste in landfills, accounting for more than half of the global methane total. Despite its significance, understanding the full extent of methane emissions from landfills has been limited.

In a recent study published in Science, researchers used advanced airborne imaging spectrometers to survey approximately 20% of the 250 active landfills in the United States. Their findings revealed substantial sources of emissions at 52% of these sites, providing new insights into the scale of methane emissions from landfills. The study highlights the importance of using high-resolution plume maps to precisely identify emission sources within landfills, enabling more targeted and effective mitigation strategies.

While landfills are known to be significant sources of methane due to the decomposition of solid waste, their exact contribution to methane emissions has not been thoroughly quantified until now. These findings underscore the urgent need for improved monitoring of landfill emissions to inform climate change mitigation policies. Given methane’s substantial role in global warming, enhanced monitoring and mitigation efforts at landfills could make a significant impact in reducing greenhouse gas emissions.

The need for action to address climate change is pressing not only in the United States but also globally, particularly in developing countries where waste management and monitoring may be lacking. While airborne monitoring of methane emissions from landfills is not a comprehensive solution for quantifying total emissions, the ability to geolocate emission sources represents a valuable contribution to this field. By enhancing monitoring and mitigation strategies, policymakers can take decisive steps toward mitigating the effects of climate change.

This study was led by researchers at Arizona Institute for Resilience and Center for Global Discovery and Conservation Science at the University of Arizona, Carbon Mapper, NASA Jet Propulsion Laboratory, Scientific Aviation and the Environmental Protection Agency with corresponding author Daniel H. Cusworth.

Managing Correspondent: Gurminder K. Paink 

Press article: U.S. landfills emit significant amounts of methane (EurekAlert!)

Original Journal Article: Quantifying methane emissions from United States landfills (Science)

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