Most polluting landfills emit as much methane as 1 million SUVs: Report

In the fight against climate change, carbon dioxide often commands the spotlight. However, a recent report from the UCLA Law Emmett Institute on Climate Change and the Environment identified a more potent threat: methane emissions from the global waste sector.

Using satellite data from the nonprofit Carbon Mapper, researchers identified 25 super-emitting landfills across 18 countries. These sites represent the most acute sources of methane leaks on the planet, with emission rates so high that they are detectable from space.

These facilities are found across the Global North and South, including Brazil, Chile, India, Saudi Arabia, Turkey, Algeria, Argentina, Greece, Hong Kong, Indonesia, Iran, Israel, Kuwait, Malaysia, Mexico, the Philippines, Thailand, and the US.

As a greenhouse gas, methane is far more aggressive than carbon dioxide in the short term, possessing over 80 times the warming potential over a 20-year period. 

Researchers from UCLA’s STOP Methane Project analysed data of around 3,000 plumes from more than 700 waste sites worldwide to identify the top 25 sites globally. These sites were responsible for the most acute hourly emission rates seen by the instruments worldwide, with emission rates ranging from 3.6 to 7.5 tonnes of methane per hour.

More dangerous

Methane is produced in landfills when organic waste, such as food scraps, paper, and wood, decomposes in oxygen-free conditions. As urban populations swell and waste management infrastructure fails to keep pace, these trash mountains transform into chemical reactors.

According to the report, a single landfill emitting 5 tonnes of methane per hour contributed as much to global warming as nearly one million SUVs on the road. The most polluting is the Campo de Mayo landfill near Buenos Aires, Argentina, which released an estimated 7.6 tonnes of methane per hour. 

Other major hotspots include sites in Indonesia, Malaysia, and India. Specifically, the Jawahar Nagar landfill in Hyderabad and the Kanjurmarg landfill in Mumbai were flagged for their significant contributions to global warming, ranking 4th and 12th respectively.

The report also identified two additional “Dishonorable Mentions” for waste sites with emissions rates that fall within  the  top 25 range, if observations since the end of 2025 are also included. These are sites near Istanbul, Turkey and Abidjan, Ivory Coast. As Turkey prepares to host COP31, it has launched an initiative to clean up its waste sector. The landfill near Istanbul shows a larger emissions rate than any of the top 25 sites, found the report. 

“This list shows there is a lot of work to be done and not just by the COP31 host,” said Cara Horowitz, executive director of the UCLA Emmett Institute. “We are talking about seriously dangerous levels of methane coming from the waste sector in a wide variety of countries. Many of these sites sit close to cities, and their emissions pose real risks to public health. The good news is that governments and landfill operators can take practical steps to prevent these massive plumes.”

Impact on communities 

Beyond the climate impact, these emissions pose a direct threat to local communities. Methane is a precursor to ground-level ozone, a primary component of smog that causes respiratory issues and premature deaths. Because many of these super-emitters are located near densely populated urban centers like Jakarta, Istanbul, and Mumbai, the plumes represent a dual crisis of climate change and public health.

The report highlighted that mitigation is both technologically feasible and cost-effective. Strategies such as organic waste segregation, installing gas-capture systems, and implementing waste-to-energy recovery can eliminate the majority of these plumes. In Chile, for example, two landfill operators have already begun corrective measures after being identified in previous satellite surveys.

By cleaning up these 25 sites, the world could achieve a massive reduction in warming potential in a matter of years, rather than decades, the report concluded.