India hosts two of the world’s 25 largest methane-emitting landfill sites, in Secunderabad and Mumbai, a new satellite-based analysis has found
The report links the sites to what it calls their “potentially responsible operators” — Ramky Enviro Engineers and Antony Waste Handling Cell Ltd
Methane is a potent greenhouse gas, and experts say cutting emissions is one of the fastest ways to slow global warming
India hosted two of the world’s 25 largest methane-emitting landfill sites in 2025 — in Secunderabad, Telangana and Mumbai, Maharashtra — according to a new satellite-based analysis of global pollution hotspots.
The sites have been linked by the report to their “potentially responsible operators” — Ramky Enviro Engineers in Hyderabad and Antony Waste Handling Cell Ltd in Mumbai. Down To Earth has reached out to both companies for comment and will update this report upon receiving a response.
The findings draw on satellite data processed by independent non-profit Carbon Mapper and analysed by the Stop Methane Project (SPM) at the University of California, Los Angeles. The team identified the landfills with the highest emissions rates seen from January 1, 2025, to December 31, 2025.
Of the 25 biggest emitters, Chile and Brazil had the highest number of landfill-site polluters, with three each, followed by Saudi Arabia, India and Turkey. There were more than 2,994 plumes from 707 waste sites, including landfills and dumpsites, worldwide, according to SPM.
Methane is a potent greenhouse gas and a major driver of short-term global warming. Although it remains in the atmosphere for far less time than carbon dioxide — about 12 years — it traps significantly more heat in the near term. Over a 20-year period, methane is estimated to be around 86 times more effective at trapping heat than carbon dioxide, according to the International Energy Agency (IEA).
The IEA says methane is responsible for roughly 30 per cent of the rise in global temperatures since the Industrial Revolution, while atmospheric concentrations are now around two-and-a-half times higher than in the pre-industrial era.
Information on “potential responsible operators” was compiled through research conducted by SPM’s team at the UCLA Emmett Institute, drawing on publicly available evidence.
Identifying some landfill sites, such as those in Hong Kong, was “pretty straightforward”. “The plumes detected in Hong Kong could be traced to a landfill clearly marked on public mapping sites, as well as on government sites,” SPM said.
Once SPM obtained the name of the facility, it was able to identify the potentially responsible operator using government sources, “which specified exactly who was responsible for the construction and operation of the landfill”.
Landfills release methane when organic waste such as food, paper and garden material breaks down without oxygen. Where such waste is left untreated, landfill sites can become major sources of methane emissions.
While many landfills emit only a few dozen kilograms of methane per hour, those on the top 25 list emitted far more, “ranging from 3.6 to about 7.5 tonnes of methane per hour,” said SPM.
The scale of these emissions has significant implications for global warming. The report noted that a source emitting around five tonnes of methane per hour has a warming impact comparable to one million large sport utility vehicles or a 500-megawatt coal-fired power plant.
Delhi’s Ghazipur landfill has previously been identified as one of the world’s major methane “super-emitter” sites. An earlier report found that its most severe leak event, in April 2022, released more than 400 tonnes of methane an hour — equivalent to the pollution from around 68 million cars running at the same time.
Experts say cutting methane emissions is one of the fastest ways to slow global warming. It is technically feasible to curb more than 70 per cent of emissions from oil and gas operations, as per IEA estimates from a 2023 report.
According to the IEA’s Global Methane Tracker 2025, the energy sector emitted about 145 million tonnes of methane in 2024, with oil and gas operations responsible for more than 80 million tonnes of that total.
Earlier, SPM had analysed methane emission from the oil and gas sector and reported on how 15 of 25 top emitters in the sector were all based out of Turkmenistan.