Methane Alert and response system (MARS): IMEO’s satellite-based system for detection and attribution of methane point sources around the world

The reduction of anthropogenic methane emissions, and especially those from the fossil fuel industry, is one of the most effective ways to slow down global warming in the next decade. Methane emissions from fossil fuel activities often happen as plumes emanating from strong point sources, such as flares, compressor stations, storage tanks, and mine vents.

The Sentinel-5P TROPOMI mission can detect the largest plumes from these sources daily and at a global scale thanks to its continuous spatial coverage and daily temporal resolution. Complementary to TROPOMI, several high spatial resolution satellite missions with sensitivity to methane are now being used to attribute plumes to point sources. These missions, so-called point-source imagers in the methane mapping context, sample the methane absorption features in the shortwave infrared with a spatial resolution of 20-60 m, enabling the detection and attribution of plumes from point sources >200-1000 kg/h. Point-source imagers can be hyperspectral (also known as imaging spectrometers), including the GHGSat, PRISMA, EnMAP, and EMIT missions, and multispectral instruments, such as Sentinel-2, Landsat, and WorldView-3. The observations by these point-source imagers often follow a previous identification of large methane hotspot areas by TROPOMI.

In connection with this increasing landscape of methane-observing satellites, the United Nations Environment Programme (UNEP) is implementing a Methane Alert and Response system (MARS) as part of its International Methane Emissions Observatory (IMEO). MARS was recently launched at COP27 in direct support to the Global Methane Pledge. It relies on the combined use of multiple methane-observing satellites for the systematic detection, attribution and monitoring of methane sources. In its initial phase, the focus is on point sources associated to the energy sector.  

In this contribution, we will describe the satellite component of MARS and will provide examples of how satellites are being used to detect and mitigate active methane point sources from the energy sector around the world.