A recent study published in Science reveals that more than half of U.S. landfills are significant sources of methane emissions, highlighting a crucial area for climate action. Methane, a potent greenhouse gas, is the third-largest contributor to U.S. methane emissions.
The comprehensive assessment, led by Carbon Mapper in collaboration with NASA Jet Propulsion Laboratory, Arizona State University, University of Arizona, Scientific Aviation, and the Environmental Protection Agency (EPA), marks the largest analysis of its kind.
According to the study, approximately 52% of landfills surveyed showed observable methane emission points. This is a stark contrast to the oil and gas sector, where only about 0.2% to 1% of sites are classified as \"super-emitters\"—sources releasing at least 100 kilograms of methane per hour.
Dan Cusworth, a scientist at Carbon Mapper and the study's lead author, emphasized the importance of targeting these high-emission sites. \"Addressing these high methane sources and mitigating persistent landfill emissions offers a strong potential for climate benefit,\" he stated.
Unlike the oil and gas sector, where methane leaks are typically short-lived, 60% of high-emitting landfills experienced methane leaks that persisted for months or even years. This persistence presents a unique opportunity for regulators and companies to implement long-term solutions.
The study also criticized the EPA's greenhouse gas reporting system for underestimating methane emissions from landfills by a factor of 1.4. With the advent of more aerial and satellite surveys, regulators will be better equipped to accurately measure and address methane emissions from these sites.
As efforts to combat climate change intensify, this study underscores the need to include landfills more prominently in regulatory frameworks and voluntary programs, alongside traditional targets like oil and gas operations.
