A recent aerial survey has revealed that US landfills are major methane emission sources, contributing notably to the country’s greenhouse gas footprint. The study by the journal Science published on Thursday shows that more than half of the US landfills surveyed are emitting methane at levels that classify them as “super-emitters.”
Landfills Surpass Oil and Gas in Methane Emissions
This significant finding shows the role of landfills as a major source of methane emissions, a potent greenhouse gas with far-reaching implications for climate change. The United States Environmental Protection Agency (EPA) ranks landfills as the third-largest source of methane emissions in the country.
Conducted by the Carbon Mapper research team in collaboration with NASA Jet Propulsion Laboratory, Arizona State University, University of Arizona, Scientific Aviation, and the EPA, this comprehensive survey revealed that 52% of the examined landfills release methane in quantities that mark them as super-emitters.
This stands in marked contrast to the oil and gas industry, where only 0.2% to 1% of sites are identified as super-emitters, defined by the EPA as sources releasing over 100 kilograms of methane per hour.
The findings further highlight that 60% of these significant landfill methane sources have been leaking persistently for months, if not years, diverging from the typically short-lived leakage events observed in the oil and gas sector.
A Call to Action for Climate Mitigation
Dan Cusworth, a lead scientist at Carbon Mapper, stressed the critical need to address these emissions promptly to benefit the climate. This study shifts attention towards landfills, which have historically garnered less scrutiny compared to the oil and gas sectors. Advances in aerial and satellite surveillance technology now equip regulators with the necessary tools to accurately measure and manage methane emissions.
Previously, methane emission estimates from landfills were primarily derived from models and ground-level surveys, which seem to underestimate the actual emission levels significantly. The aerial surveys conducted revealed that emission rates were 1.4 times higher than earlier estimates reported by the EPA. In 2021, methane was responsible for 12% of all US greenhouse gas emissions from human activities, according to the EPA.
Major Methane Emission Sources: A New Focus
This study represents a crucial step forward in our grasp of and response to methane emissions from US landfills. It highlights the pressing necessity to revisit emission estimates and escalate actions to tackle methane leaks.
Acknowledging landfills as significant sources of major methane emissions shifts the spotlight onto their contribution, providing a novel angle for climate change mitigation efforts. The imperative for augmented regulatory oversight and innovative strategies to diminish the environmental footprint of landfill operations has never been more critical.
Image Source: HWH Environmental
