Gaseous Waste Update
Landfills and Methane: Old Lessons, New Insights (published Waste360.com 11/12/25)
Years ago, I wrote for MSW Management magazine about landfill methane capture and the growing number of facilities turning waste gas into usable energy. At the time, the promise was clear: landfills could be more than repositories of refuse—they could become sources of renewable fuel.
Recently, Nature magazine revisited this issue with sobering new findings (https://share.google/eT5RligxwcqlxhZIJ).
Global satellite survey reveals uncertainty in landfill methane.
Methane is a potent but short-lived greenhouse gas. Rapid reductions in human-caused emissions could significantly slow near‑term warming. Solid waste alone contributes about 10% of global methane emissions through the anaerobic decay of organic material.
High‑resolution satellites now allow scientists to monitor methane “hotspots,” especially in urban areas where landfills are among the most prominent sources. A survey of 151 disposal sites across six continents revealed that satellite-based estimates often diverge sharply from reported or modeled facility emissions. This mismatch underscores major uncertainties in current inventories and highlights the need to reconcile bottom‑up reporting with top‑down atmospheric measurements.
The study also found that managed landfills emit less methane per unit area than unmanaged dumps, with emissions concentrated in open, uncovered sections where fresh waste is deposited. These insights demonstrate the value of satellite monitoring in identifying and mitigating waste-sector emissions.
The broader context is daunting: global waste production has nearly tripled since 1965, reaching 2 billion tonnes annually by 2016. With population growth, waste generation is projected to rise another 70% by 2050. Today, about 70% of waste ends up in landfills or dumps, where anaerobic decomposition produces methane.
Methane’s atmospheric lifetime is roughly nine years, yet it accounts for about 30% of human‑induced warming—second only to carbon dioxide. In the U.S., landfills are the third‑largest source of methane emissions.
The more organic material we can compost and divert from landfills, the better. Expanding landfill gas collection systems, while simultaneously reducing the flow of food and yard waste into disposal sites, remains the most effective strategy to curb these harmful emissions.
Methane may be short-lived, but its impact is powerful. The challenge—and opportunity—lies in acting quickly, combining technology, policy, and community practices to transform waste management from a liability into a climate solution.
Comments