The methane missing from the register

Twelve places, all of them landfills#

Four satellites measure methane in the sunlight reflected off the ground, because methane absorbs part of the infrared: EMIT (NASA, on the Space Station), Tanager (Planet), EnMAP (the German space agency) and PRISMA (the Italian space agency). Each pixel covers 30–60 metres. The nonprofit Carbon Mapper and the UN methane observatory (UNEP IMEO) publish the plumes they find, with the day, the place and the rate per hour.

In Romania, all 12 places where they have published methane plumes are landfills in the EU register. On the map, each plume has its real shape, enlarged to be visible, and the glow around it grows with the amount. Methane comes from waste rotting without air, and it warms the climate about 80 times more than carbon dioxide over its first 20 years.

What each operator reported#

Large landfills in the European Union report each year, in the EU pollutant register (E-PRTR), how many tonnes of methane they released, if the amount passes 100 tonnes. The latest published year is 2024. Of the 72 landfills in the 2024 register, only 18 have a methane entry; Carbon Mapper satellites have imaged 64 of them.

A place enters the comparison only if its plume was seen on at least three different days or by at least two satellites: 6 of 12. For each, the Carbon Mapper average (satellite passes with no plume count as zero), minus its margin of error, is multiplied by the 8,760 hours in a year: what a year would add up to if the rate seen held. At 5 of 6, this yearly equivalent is at least 10 times the amount reported for 2024 or, where there is no methane entry, the 100-tonne threshold.

Three landfills with no methane in the register#

The landfills at Cluj (Pata Rât), Oradea and Albota (near Pitești) are in the EU list of installations for 2024, in operation, but have no methane entry for 2024 or 2023. The register requires a methane entry from 100 tonnes a year upwards.

At Cluj, the plume was seen on 6 days between February and August 2026, by two satellites; Carbon Mapper caught it on 3 of its 6 passes, averaging 450 kg an hour. With the margin of error taken off, if that rate held all year it would come to at least 3,138 tonnes. At Oradea: 5 days, at least 1,095 tonnes a year on the same calculation. At Albota: 7 days, at least 1,347 tonnes. The Oradea landfill's last methane entry is for 2012 (11,200 tonnes); the Albota one's, for 2008.

Vidra: a plume on every pass#

The Vidra landfill, south of Bucharest, is the most visible place in the country. Since July 2022 its plume has been seen on 24 days, by four different satellites, including all 11 Carbon Mapper passes since August 2024. The Carbon Mapper average: 2,064 kg of methane an hour.

The operator, SC ECOSUD SRL, entered 412 tonnes for 2023, as an estimate, and 332 tonnes for 2024: 38 kg an hour on average. A single day cannot show that a yearly total is wrong, but the rates measured on particular days are far above the hourly average implied by the reported totals: on 17 July 2022 PRISMA measured 3,342 kg an hour, against 54 kg an hour for the 2022 total; on 16 November 2023 EnMAP measured 2,262 kg an hour, against 47; on 2 August 2024 EMIT gave between 688 and 2,276 kg an hour depending on the organisation, against 38. The SMART-CH4 research project (CEA, France) published a similar gap for Vidra in July 2026.

Each square is one satellite pass; the coloured ones caught a plume, the ones with a dot are UNEP IMEO detections with no published image. Images: Carbon Mapper (data.carbonmapper.org), colours changed.

Brașov: the reported amount fell, satellites see plumes#

The Fin-Eco landfill in Brașov reported 11,000 tonnes of methane for 2020, then 2,260 for 2021, 130 for 2022, 312 for 2023 (calculated with LandGEM, a model of the gas a landfill gives off) and 389 for 2024. No public source found explains the fall. The observations from orbit begin only in 2023, so they do not show what happened in the years of the fall.

Satellites saw it on 9 days, from April 2024 to July 2026; Carbon Mapper caught it on 4 of its 10 passes. The Carbon Mapper average, counting passes with no plume as zero, is 627 kg an hour: if it held all year, at least 4,349 tonnes. On 15 April 2024 EMIT measured 1,149 kg an hour; the total reported for 2024 averages 44 kg an hour.

Iași: here the numbers agree#

The comparison does not find gaps everywhere. The Salubris landfill in Iași reported 1,440 tonnes for 2024; satellites saw it on 3 days, and the rate seen, with the margin of error taken off, would give 1,263 tonnes in a year. The amount reported is even higher.

Elsewhere too, agreement at a single landfill is not the rule: an aircraft study of US landfills found, in total, 1.4 times the reported amount at landfills with at least ten passes, with mismatches in both directions from one site to the next.

What satellites miss: the wells#

Carbon Mapper satellite images have covered at least part of the oil-field area of Prahova and Dâmbovița 23 times, of Gorj, Vâlcea and Argeș 22 times and of the Jiu Valley coal basin 3 times. The catalogue has no methane plume from oil, gas or coal in Romania; the plumes caught in these images come from landfills.

That does not mean no methane escapes. Ground measurements in 2019 put the average well at about 5 kg an hour, while the smallest plume published in Romania is about 140 kg an hour. The same measurements estimated methane emissions from Romania's oil production at about 120,000 tonnes a year, around 2.5 times what was reported. Wells need sensors carried by cars and aircraft; for landfills, orbit is enough.