Satellites expose methane leaking from Turkey's landfills ahead of COP31

Satellites have caught Turkey's rubbish dumps red-handed. Researchers at the University of California, Los Angeles analysed public Carbon Mapper data from the Tanager-1 satellite between January 2025 and the end of May 2026, and found 70 methane plumes across the country's 10 highest-emitting waste sites, according to Reuters. Average detected rates at those sites ran from 841kg to 7.4 tonnes an hour, with three hotspots clustered near Istanbul and others close to Ankara, Izmir and Antalya — the city hosting COP31 from Nov 9 to Nov 20.

The worst single offender sits in countryside west of Istanbul near Seymen, where trucks haul in mixed household waste from a city of 16 million people. Its average detected rate of about 7.4 tonnes an hour lands just below the highest-emitting landfill on a global list from 2025. "What stands out is how big its emissions are and how persistently large they are," said Tia Scarpelli, waste sector lead at emissions-monitoring non-profit Carbon Mapper.

Turkey's Environment Ministry pushed back, saying the satellite data comes from snapshots rather than continuous measurement and can't be used to calculate annual emissions at Seymen. It pointed to the government's Zero Waste Initiative, saying the national waste recovery rate climbed to 37.53% in 2025 from 13% in 2017. ISTAC official Aysen Erdincler disputed that the readings were representative, saying emissions at the site typically run between 4 and 6 tonnes an hour, and that a one-day satellite reading of 12 tonnes had pulled the average up. ISTAC head Fatih Ugur said about 30ha of the landfill was left uncovered that day while crews worked on methane-collection pipes, and that low atmospheric pressure had also concentrated the gas.

Gas capture is hardly rare in Turkey — it's widespread at the country's larger municipal landfills, which is exactly the problem. The Seymen site takes roughly 8,500 tonnes of household waste a day out of Istanbul's 20,000-tonne total, and a plant opened there in 2020 burns captured gas to produce about 22,000 megawatt-hours of electricity a month, according to a 2025 report by energy news site Enerji Gunlugu. Erdincler said leaks at the site usually run around 25%. The takeaway from the UCLA work: collection systems alone don't stop big releases.

The stakes are high because methane is the second-biggest driver of climate change after CO2 and more than 80 times more potent over its first 20 years in the air. Climate TRACE data ranks Turkey as the world's fifth-biggest methane emitter from solid waste, behind China, the US, Russia and Brazil. World Bank figures built on the European Commission's EDGAR database show Turkey's waste methane rose nearly 25% in the decade to 2024, against a global increase of 6.5% — and the country's waste emissions have held around 21 million tonnes of CO2 equivalent a year since 2020.

Scarpelli said the concentration of emissions at a handful of sites is also an opportunity, with better-designed collection systems and repairs to cracked covers or faulty gas wells. "There is this huge mitigation potential by just addressing the largest landfills to reduce their national emissions," she said. Selim Yildirim, chief climate policy researcher at Ankara-based non-profit D84, said Turkey manages waste better than poorer nations but less effectively than much of Europe. Turkey isn't among the participants of the Global Methane Pledge, launched at COP26 in 2021 with a goal of a 30% cut from 2020 levels by 2030, though Yildirim said it could still sign on during COP31 — and that joining alone wouldn't guarantee anything. "The issue is whether you can effectively turn it into action and implement it," he said, calling for regulation to push operators to capture and reuse methane. For residents about 5km away in Seymen, the problem arrives through open windows: methane is odourless, but decomposing waste releases pungent compounds. "Around four or five in the morning, the smell suddenly comes," said Soner Duz, a 46-year-old barber. "It wakes you up."