Satellites flag 70 methane plumes at Turkey’s highest-observed waste sites—not an annual total

The story

A satellite-based analysis has identified 70 methane plumes across Turkey’s 10 highest-observed waste sites, exposing a concentrated opportunity for climate action just before COP31 opens in Antalya. UCLA’s STOP Methane Project compiled the list from public Carbon Mapper measurements collected by Planet’s Tanager-1 satellite between January 1, 2025, and June 1, 2026.

The largest average detected rate came from the Silivri-Seymen landfill west of Istanbul. Across the quantified observations included by UCLA, the site averaged about 7.4 metric tonnes of methane per hour—just below the top landfill average in UCLA’s global 2025 ranking. Three of the 10 Turkish sites were near Istanbul; others were near Ankara, İzmir and Antalya.

Those figures require careful interpretation. Tanager-1 does not continuously watch every landfill, and clouds, orbital timing and detection thresholds affect what it sees. UCLA required at least two observed and quantified plumes before including a site. The resulting averages describe emissions during detected events, not every hour of operation and not a calculated annual total for the facilities or Turkey as a whole.

Carbon Mapper’s platform is designed to make large methane and carbon-dioxide point sources visible at facility scale. Tanager-1 uses imaging spectroscopy to detect the distinctive absorption signature of methane and map a plume against the ground below. Algorithms then estimate an emission rate with uncertainty. That makes the data useful for locating unusual releases and prioritizing field inspections, while leaving continuous inventory accounting to complementary ground systems and statistical methods.

Turkey’s Environment Ministry challenged the representativeness of the Seymen readings in comments to Reuters. It said intermittent satellite measurements cannot define annual emissions and pointed to the country’s rising waste-recovery rate. İSTAÇ, the municipal operator, said a particularly high reading occurred while roughly 30 hectares were uncovered during work on methane-collection pipes and under low atmospheric pressure. An official estimated the site’s typical leakage at about 25%, though no continuous public dataset was supplied to reconcile that estimate with the satellite record.

Seymen is not a landfill without methane controls. İSTAÇ collects landfill gas and burns it in engines to generate electricity, one of three such systems it operates. The company says its landfill-gas plants collectively produced 700,000 megawatt-hours in 2023 and avoided about 3.5 million tonnes of greenhouse-gas emissions. The satellite results show why installed capture capacity and verified capture performance are different metrics: cracks, uncovered working areas, faulty wells or pressure changes can still create large releases.

Turkey’s own 2026 national inventory describes methane recovery as a central waste-sector measure. The filing says facility-reported recovered gas is cross-checked against electricity and heat output. It reports waste at 15.4 million tonnes of carbon-dioxide equivalent in 2024, about 2.6% of national emissions excluding land use, with methane dominating the category. Facility-scale satellite data adds an independent layer that can test where aggregate reporting may hide episodic loss.

Methane is a priority because cutting it can slow near-term warming faster than an equivalent focus on long-lived carbon dioxide alone. Landfills produce the gas when organic waste decomposes without oxygen. Better gas-well design and maintenance can reduce leaks, but the durable solution also requires diverting food and other organic material before burial. UCLA’s list is therefore a repair map and a waste-policy signal, not simply a ranking of offenders.

INNOVOX analysis: satellite transparency changes the economics of landfill management. A regulator no longer needs to inspect every square metre continuously to discover a super-emitting episode; orbital observations can direct scarce inspection teams toward the most consequential sites. Operators can also use repeat detections to validate repairs. The risk is false precision—treating an episodic tonnes-per-hour estimate as if it were a complete emissions inventory.

What to watch at COP31 is whether Turkey’s stated focus on zero waste and methane reduction produces measurable facility commitments. The strongest response would combine public plume alerts, rapid on-site verification, continuous ground monitoring at major landfills and disclosure of captured versus generated methane. Follow-up satellite passes can then answer the question that matters most: whether the largest plumes become smaller and less frequent after intervention.

INNOVOX analysis

The significance of high-resolution methane satellites is operational rather than merely accusatory. They can identify a small number of facilities where repairs, better cover and organics diversion may deliver disproportionate climate benefits. Their limits are equally important: uneven orbital coverage and weather mean a detected plume can reveal a serious event without measuring every hour of a facility’s year.

What to watch

Watch whether İSTAÇ publishes continuous ground measurements for Seymen, whether Carbon Mapper detects the same sources after repairs, and whether Turkey converts COP31’s methane priority into enforceable landfill standards. Satellite follow-up should show whether mitigation reduces plume frequency and size.