The UCLA Emmett Institute's STOP Methane project released a new ranking of super-pollutant methane emissions from the waste sector that includes Brazil among the countries with the highest presence, with three sites among the top 25 identified in 2025. The report uses public data from Carbon Mapper, based on direct 2025 observations, to identify sites with the highest quantified emission rates in the world — each representing a major opportunity for emission reduction by operators.

In total, the ranking gathers 25 waste facilities across 18 countries responsible for the highest super-pollutant emission rates detected from space by satellites. In addition to Brazil (3 sites), the list includes Chile (3), India (2), Saudi Arabia (2), Turkey (2), Algeria (1), Argentina (1), Greece (1), Hong Kong (1), Indonesia (1), Iran (1), Israel (1), Kuwait (1), Malaysia (1), Mexico (1), Philippines (1), Thailand (1), and the United States (1).

The site with the highest emission rate identified in the ranking is located near Buenos Aires, Argentina, at 7.6 tons of methane per hour — equivalent to the climate impact of more than one million SUVs. The analysis also draws attention to Turkey, which will host COP31 in November 2026 and concentrates three of the largest emission sites listed. The country recently launched an initiative to reduce emissions in the waste sector, led by First Lady Emine Erdoğan.

For the first time, the survey also includes two "dishonorable mentions" for sites that could figure among the top 25 if additional data were considered — one near Istanbul, Turkey, and another in Abidjan, Ivory Coast. The Turkish landfill, in particular, has an emission rate higher than any site present in the official ranking.

"This list shows that there is a lot of work to be done — and not just by the host country of COP31," said Cara Horowitz, executive director of the UCLA Emmett Institute. "We are talking about extremely dangerous levels of methane coming from the waste sector in various countries. Many of these sites are close to cities, and their emissions represent real risks to public health. The good news is that governments and operators can take practical measures to prevent these large plumes."

The identification of methane emissions — one of the most potent greenhouse gases — has become more precise thanks to satellite instruments capable of detecting it from orbit. UCLA's rankings are based on this public data.

Researchers from the STOP Methane project analyzed nearly 3,000 plumes from more than 700 waste sites worldwide to identify the top 25 emitters. The detected hourly rates vary between 3.6 and 7.5 tons of methane per hour. For comparison, a source emitting 5 tons per hour would have an impact equivalent to the warming caused by one million SUVs.

Two landfill operators in Chile (Penco and Talagante) have already reported mitigation measures following the initial release of the list. "We have already seen that making reliable data more accessible and increasing visibility can be an effective way to drive action," said Juan Pablo Escudero, project partner and professor at Adolfo Ibáñez University. "This data creates opportunities for responsible operators and governments to lead the cleanup of the sector."

STOP Methane is a project of the UCLA Emmett Institute, a major environmental law center in the United States, which regularly publishes accessible rankings on super-pollutant methane emissions in various sectors, including oil and gas.