UCLA Emmett Institute cites largest methane emissions from landfills around the world

Key takeaways

• UCLA's STOP Methane Project, run by the Emmett Institute at UCLA Law, has identified 25 waste facilities in 18 countries that were responsible for the most acute hourly emission rates seen by the instruments worldwide
• Emission rates range from 3.6 to 7.5 tonnes of methane per hour, contributing about as much to global warming in a year as 1 million SUVs.
• Reducing methane pollution is one of the fastest ways to slow global warming.

This year marks 250 years since an Italian physicist named Alessandro Volta first discovered methane - a colorless, odorless, short-lived but super potent greenhouse gas that is helping heat the planet. Reducing methane pollution is now recognized as one of the single fastest ways to reverse rising global temperatures - a kind of emergency brake for slowing climate change.

Fortunately, scientists and policymakers have powerful new tools for observing methane emissions. Several satellites that can detect methane from orbit are now constantly capturing images of large plumes that would otherwise be hard to detect with the naked eye and sending the data back to Earth. The trick is analyzing all that satellite data and highlighting the most important information for the public.

Enter UCLA's STOP Methane Project, run by the Emmett Institute at UCLA Law. In order to help identify the most extreme and most stubborn super-polluting plumes of methane pollution, the researchers have begun regularly publishing "user-friendly ranking lists" of the largest methane emissions detected by satellites. These lists focus on the oil and gas industry and on the waste sector. They are based on public satellite methane emissions data from the independent nonprofit Carbon Mapper.

This week, ahead of Earth Day, the team released its latest report titled "Spotlight on the Top 25 Methane Plumes in 2025: Landfills." The report ranks 25 waste facilities in 18 countries, both developed and developing countries of all income levels and in all world regions.

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 tons of methane per hour. To put that in perspective, a source emitting 5 tonnes of methane per hour (5,000 kilograms; a tonne, or metric ton, is equivalent to 1,000 kilograms) would contribute about as much to global warming in a year as 1 million SUVs. One landfill in the United States made the list: a site in Needville, Texas, outside Houston that had an emission rate of 3.8 tonnes per hour.

"We are talking about seriously dangerous levels of methane coming from the waste sector in a wide variety of countries," said Cara Horowitz, executive director of the UCLA Emmett Institute and project leader. "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."

In March, the team unveiled the Spotlight on the Top 25 Methane Plumes in 2025: Oil & Gas.

"Methane was the stealth pollutant gas for many years: invisible, out of sight and out of mind," Horowitz told The Guardian. "But we can now see these tremendously powerful emissions using satellites and use that as a wake-up call for the world."

The project builds on the Emmett Institute's earlier work - including convenings and published papers that explain satellite technology for lawmakers - to advance methane regulations globally.