Resource Use

Landfills leak large quantities of methane close to Madrid city centre

High rates of methane emission have been recorded in Madrid, after GHGSat satellites reported landfill sites close to the city centre leaking the gas at a rate of c. 8,800 kgCH4/hr.

Originally noted on 20 August, the largest leak emitted methane at a rate of approximately 5,000kg per hour, with follow-up observations taken on 13 October demonstrating that greenhouse gases (GHGs) were still being released. Satellite imagery has suggested that a cloud of methane is to slowly drift over neighbouring residences if the emission of gas is not halted.

GHGSat: landfill methane emissionsResearchers at SRON Netherlands Institute for Space implemented methane hotspot mapping in order to identify the area, using ESA Copernicus TROPOMI data to pinpoint the exact location of the leakage. High resolution satellite imaging was then carried out by GHGSat, with which methane plumes were captured emanating from two landfill sites located 18km outside of the centre of Madrid – it is estimated that if the combined rate of release were to be sustained for a year, 350,000 homes could have been powered with the methane lost. The exact cause of the emissions is unknown at present, though GHGSat’s primary observations were made days after Madrid recorded its highest ever temperature (40.72°C) during a heatwave which ‘scorched much of Southern Europe’. The data has since been shared with the site operator.

GHG capture and the impacts of methane

According to The 1999 Landfill Directive, EU landfill operators are required by law to capture any gases released in the decomposition of organic matter. This should then either be made use of within the generation of energy or burnt off through flaring.

The majority of landfills across Europe and North America typically comply with this legislation, sealing off waste disposal sites from the surrounding environment, considered ‘sanitary’ as a result. Throughout the Global South, however, waste can often end up in open landfills, which act as sources of airbourne pollution and water table contamination. That being said, GHGSat has observed landfills emitting large quantities of methane across North America, Europe, Latin America, and Asia.

This is problematic, GHGSat suggests, as 30-50 per cent of manmade global warming is attributed to methane, with 26 per cent of Europe’s methane emissions coming from waste, according to the European Union Methane Strategy. In fact, globally, landfills are predicted to produce 8 - 10 per cent of all anthropogenic methane emissions by 2025. If the pledge to cut GHG emissions - down 55 per cent from 1990 levels by 2030 – made by European policymakers is to be achieved, then the emission of methane from landfill sites should be tackled.

Ilse Aben, from SRON, commented: “This new finding again demonstrates the strong synergy between TROPOMI’s global coverage and high-resolution instruments like GHGSat and shows how we can spot methane emissions everywhere around the world including in Europe.”

Stephane Germain, CEO of GHGSat, added: “Thanks to our expanding fleet of satellites, we now provide data that would have been impractical and expensive to collect just a few years ago. With this information, operators and communities can build business cases for capturing landfill gas, providing new sources of revenue while mitigating their impact on climate.

“In addition, our data can help countries audit their climate impacts and more accurately monitor the progress of their Nationally Determined Contributions under the Paris Agreement.”