High-resolution satellites have detected substantial quantities of methane leaking from adjacent landfill sites close to the centre of Madrid, Spain. Using data from the Copernicus Sentinel-5P mission combined with GHGSat’s high-resolution commercial imagery, scientists from the SRON Netherlands Institute for Space Research and GHGSat discovered both landfill sites combined emitted 8800 kg of methane per hour in August 2021 – the highest observed in Europe by GHGSat.