Seymen: Satellite data has detected significant methane emissions from several landfill sites in Turkey, raising questions about the country's waste management practices just days before it hosts the United Nations Climate Change Conference, COP31.
Researchers identified 70 methane plumes from ten of Turkey's highest emitting waste sites between January 2025 and the end of May 2026. The findings highlight the difficulty of controlling greenhouse gas emissions from landfills despite efforts to capture methane and generate electricity from it.
The Seymen landfill in Silivri, west of Istanbul, recorded an estimated average methane emission rate of approximately 7.4 metric tonnes per hour, based on satellite observations. The facility receives large quantities of household waste from Istanbul, one of Turkey's most populated cities.
The satellite data was analysed by researchers at the University of California, Los Angeles, using information from Carbon Mapper's Tanager-1 satellite. The researchers also identified methane plumes at waste sites near Ankara, Izmir and Antalya, as well as Istanbul.
Methane is the second largest contributor to global warming after carbon dioxide. It has a much stronger warming effect over a 20 year period, making its reduction an important part of international climate action.
Methane is released when organic materials, including food waste, break down in landfills without sufficient oxygen. Although it remains in the atmosphere for a much shorter time than carbon dioxide, its strong warming effect makes it a major concern for climate scientists.
The findings come as Turkey prepares to host COP31 in Antalya from November 9 to 20. The conference will bring together governments and climate experts to discuss ways of addressing global warming and strengthening national climate commitments.
The Turkish government has identified zero waste and methane reduction as important priorities for the conference. A high level discussion on zero waste and methane reduction is scheduled for November 11 as part of the Antalya Leaders' Summit programme.
However, the satellite findings have drawn attention to the difficulties Turkey faces in reducing emissions from its own waste management facilities.
According to data cited in the investigation, methane emissions from Turkey's waste sector increased by nearly 25 per cent between 2014 and 2024. During the same period, global waste methane emissions increased by approximately 6.5 per cent.
Turkey's annual emissions from the waste sector have remained at around 21 million tonnes of carbon dioxide equivalent since 2020. This measurement expresses the warming impact of greenhouse gases in terms of carbon dioxide.
According to Climate TRACE, Turkey is the world's fifth largest emitter of methane from solid waste, behind China, the United States, Russia and Brazil.
Turkey's Environment Ministry has questioned the interpretation of the satellite observations, arguing that they do not provide continuous measurements of emissions throughout the year. The ministry has also highlighted improvements made through the country's Zero Waste Initiative.
The government says Turkey's waste recovery rate increased from 13 per cent in 2017 to 36.08 per cent in 2024 and 37.53 per cent in 2025. It aims to increase the rate to 60 per cent by 2035 and 70 per cent by 2053.
The Zero Waste Initiative promotes recycling, waste separation and the recovery of materials that would otherwise be sent to landfill sites.
Officials responsible for the Seymen facility have also challenged the suggestion that the satellite readings represent normal operating conditions.
İSTAÇ, the municipal waste management operator responsible for the facility, said methane emissions generally ranged between four and six tonnes per hour. Officials explained that repairs to methane collection pipes had left around 30 hectares of the landfill uncovered.
The officials also attributed the unusually high satellite reading partly to low atmospheric pressure, which they said had contributed to a higher concentration of methane during the observation. One satellite measurement recorded emissions of approximately 12 tonnes per hour.
An İSTAÇ official estimated that methane leakage at the facility was normally around 25 per cent. However, researchers could not independently establish how much methane the landfill's collection system captures.
The investigation also highlighted Turkey's position in international efforts to reduce methane emissions. The country has not joined the Global Methane Pledge, launched by the United States and the European Union at COP26 in 2021.
The pledge aims to reduce global human caused methane emissions by at least 30 per cent from 2020 levels by 2030. More than 110 countries and the European Union have joined the initiative.
Turkey, however, participates in other international methane related programmes, including the Global Methane Initiative.
The satellite findings also highlight the environmental concerns of people living near major waste disposal facilities. Residents near the Seymen landfill have complained about unpleasant smells from decomposing rubbish, particularly during early morning hours.
Methane itself is odourless. Other gases and compounds released during the decomposition of waste are responsible for many of the unpleasant smells associated with landfill sites.
Better separation of organic waste, improved landfill covers and regular maintenance of gas collection systems are among the measures that can help reduce methane emissions. Carbon Mapper experts have also highlighted the importance of monitoring major emission sources and improving waste management practices.
The satellite findings do not establish the total annual methane emissions from the Seymen landfill, as the observations provide measurements at particular times rather than continuous monitoring. Nevertheless, they highlight the importance of improving waste management and ensuring that methane collection systems operate effectively.
As Turkey prepares to welcome international climate leaders, the issue presents an important test of how countries can translate their environmental commitments into practical action.
The discussions at COP31 are expected to place renewed attention on reducing methane emissions and improving waste management, two areas that will be essential to limiting the impact of climate change.