b"FLUXES The European Greenhouse Gas Bulletinproducing regions. This allows us to see quite quickly ifIf you transect the plume 10 times, you will get 10 there are changes, she continues. very different results usually, and sometimes they can be It is hoped that this type of technology will supportan order of magnitude different, so that's really big laws like the EUs upcoming methane regulation bybecause the plume dynamics change so quickly, providing a reference point to see if the data provided isexplained Rckmann. While there are some ways to accurate. reduce the meteorological variability, including taking Having the ability to see what the emissions are willmeasurements from further away, it is still a problem.allow us to set a baseline that then can be used in theThe most precise approach at the moment is the tracer EU for its current gas purchases, but then also acrossrelease approach, where researchers release a gas not the board for buyers and sellers, says Sollazzo. present in the area and measure it together with the unknown gas. This helps boost the accuracy of emission Ground-based monitoring helps estimates, but can only be done when the emission point pin down leakshas been located and does not work when there are lots of emission points, such as in landfills.While the exact range at which a satellite can measure methane emissions varies, they can only detect very bigCooperation to use and improve MRVemissions. They do not provide all of the information neededWhile there is no global standard for MRV for methane to go out and fix leaks, says Ioannis Binietoglou fromemissions yet, the EU's methane law will help standardise the non-profit Clean Air Task Force. He wants to see asome approaches. mix of complementary technologies, including ground- Meanwhile, the US has a Greenhouse Gas Reporting based measurements and emissions estimates, createdProgram that requires monitoring and reporting by regu-using models or engineering calculations. lated sources, including for methane emissions from Ground-based methods include using flux chamberspetroleum and fossil gas facilities. This is verified to capture and measure emission levels and lasers onthrough a combination of automated and manual checks mobile equipment, like drones and vehicles that canthat flag potential errors.capture real-time data. These have to be converted toAnother prominent system is run by the Oil and Gas emission estimates. Methane Partnership, a group of companies working with The approach of the mobile analysers is superthe United Nations to apply advanced monitoring and successful, says Dr Thomas Rckmann, Professor atshare best practices.Utrecht University. The groups gold standard of MRV requires direct You have some idea from the modelling on the foot- measurements of source-level methane emissions print area, but then the mobile analyser can go to thecomplemented by measurements of site-level methane footprint area and try to find out where the point ofemissions. This standard is used in over 38% of the global emission is. Often you know that there is a farm or thereoil and gas production. It also forms the basis of the EUs is a wastewater treatment plant and so on, but then youmethane regulation.go to all these individual installations and find out howWhile MEP Paulus believes the new EU law will be a they emit. So with these methods atmospheric researchbig driver of methane emissions reductions around the goes to a much more granular scale, he adds. world, more work is needed on the verification side.Rckmann has used the technology to measureWe do have a problem there because we simply don't methane leaks in city gas networks and in previouslyhave enough verifiers out there yet. I'm pretty confident unstudied oil and gas production areas in Romania. Inthat we still have some time [.] to bring them on board both cases, the additional data helped raise awarenessand to have sufficient people out there who can actually of the methane emissions and technology that can beverify those emissions, she explains.used to track them. Methane is a complicated greenhouse gas and there are However, there are still challenges in taking ground- still gaps in tracking emissions. Improved observation can based measurements, especially the accuracy of thehelp bridge these gaps, increase understanding of what is emission estimates. This is because emission plumeshappening in the atmosphere and boost global efforts to move with the wind. reduce its impact on the climate, but more is still needed."