Landfills Emitting Methane at Alarming Rates, Study Finds
A recent study published in the journal Science has shed light on the alarming rate at which landfills are emitting methane, a potent greenhouse gas that contributes to climate change. The study, which measured methane emissions at about 20 percent of large, operating landfills in the United States, found that these sites are emitting methane at almost three times the rate reported to federal regulators.
Riley Duren, founder of Carbon Mapper and a former NASA engineer, emphasized the significance of the study in uncovering the true extent of emissions from landfills. “We’ve largely been in the dark, as a society, about actual emissions from landfills,” said Duren. “This study pinpoints the gaps.”
Landfills are the third largest source of human-caused methane emissions in the United States, according to the Environmental Protection Agency. Organic waste like food scraps can emit copious amounts of methane when they decompose, contributing to the problem.
The study utilized airplane flyovers equipped with imaging spectrometers to measure methane concentrations in the air above landfills. Researchers detected emissions hot spots at more than half of the landfills surveyed, indicating leaks of trapped methane from decomposing trash buried beneath the surface.
Daniel H. Cusworth, a climate scientist involved in the study, described the phenomenon as a “garbage lasagna,” highlighting the layers of trash that can release methane over decades. While many landfills have systems in place to collect and manage methane emissions, leaks can occur, contributing to the problem.
The researchers emphasized the importance of pinpointing leaks to not only better understand emissions but also to help landfill operators address the issue. Strategies such as composting food scraps to reduce waste going to landfills could also help mitigate methane emissions.
Looking ahead, initiatives like Carbon Mapper’s methane-tracking satellites aim to provide a more comprehensive understanding of methane emissions globally. With the launch of MethaneSat by the Environmental Defense Fund and plans for Carbon Mapper’s own satellite, efforts to monitor and reduce methane emissions from landfills and other sources are gaining momentum.
