Satellite Data Identifies India's Secunderabad and Mumbai Landfills as Global Methane Hotspots

India hosted two of the world's 25 largest methane-emitting landfill sites in 2025, at Secunderabad in Telangana and Mumbai in Maharashtra, according to satellite-based analysis by the Stop Methane Project at UCLA and Carbon Mapper. The sites have been linked to Ramky Enviro Engineers in Hyderabad and Antony Waste Handling Cell Ltd in Mumbai as potentially responsible operators.

The analysis identified 25 global landfill sites with the highest methane emission rates from January to December 2025, detecting more than 2,994 methane plumes from 707 waste sites worldwide. The top 25 sites emitted between 3.6 and 7.5 tonnes of methane per hour. A source emitting approximately 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. Chile and Brazil each had three sites in the top 25, followed by Saudi Arabia, India and Turkey with two each.

Methane is estimated to be around 86 times more effective at trapping heat than carbon dioxide over a 20-year period, according to the International Energy Agency. Atmospheric methane concentrations are now approximately two and a half times higher than in the pre-industrial era, and the IEA attributes roughly 30 per cent of the rise in global temperatures since the Industrial Revolution to methane. Landfills generate methane when organic waste including food, paper and garden material decomposes without oxygen. Delhi's Ghazipur landfill was previously identified as a major super-emitter: a leak event in April 2022 released more than 400 tonnes of methane per hour, equivalent to pollution from approximately 68 million cars.

Experts say cutting methane emissions is one of the fastest available routes to slow near-term global warming. IEA estimates from a 2023 report indicate that more than 70 per cent of emissions from oil and gas operations are technically feasible to curb. The energy sector emitted approximately 145 million tonnes of methane in 2024, with oil and gas operations responsible for more than 80 million tonnes of that total. The UCLA analysis previously found that 15 of the 25 top methane emitters in the oil and gas sector were based in Turkmenistan. The identification of Indian landfill sites as global hotspots underscores the methane reduction potential in municipal solid waste management.

Key figure — 3.6 to 7.5 tonnes of methane per hour emitted by top 25 landfill sites