Decarbonisation Technology May 2022 Issue

studies, methane emissions from the energy sector in 2021 totalled 135 Mt (see Figure 1 ), 70% higher than those declared in national submissions. In a note of encouragement, the IEA also mentioned that while overall energy use recovered by 10% in 2021, the methane emissions from the energy sector grew by just under 5%, indicating that efforts to reduce emissions may be starting to pay off (IEA, 2022). That said, the IEA makes it clear that we are not yet on track to meet the goals of the Global Methane Pledge. The IEA also found a significant difference in emissions intensity across different countries, with a methane emissions intensity from the worst performers 100 times that of Norway, the best performer.  International Methane Emissions Observatory (IMEO) The IMEO is a new UNEP initiative with support from the European Commission and the US Government to commission measurement studies and to collect and integrate diverse methane emissions data from a range of sources to establish a global public record of empirically verified methane emissions (IMEO, 2021). IMEO ingests data from four streams: OGMP 2.0 company reports, direct data measurements from scientific studies, remote sensing data from satellite observations (TROPOMI, GoSat & MethaneSAT), and national inventories (IMEO, 2021). IMEO’s first report was published in 2021. It will be important to follow progress with the global initiatives via these monitoring activities. Related initiatives Although not focused on methane, the World Bank’s Global Gas Flaring Reduction Partnership (GGFR) is committed to ending venting and routine flaring of gas associated with crude oil production sites across the world. While flaring is better than venting, the default option should be to avoid methane emissions from venting or CO2 emissions from flaring by capturing and conserving the associated natural gas. Signatories to the GGFR Zero Routine Flaring

satellite imagery with high-resolution atmospheric modelling and machine learning algorithms to detect and quantify methane plumes. These estimates can be aggregated at a national scale to evaluate the contribution of ultra-emitters to national reported emissions (CCAC, 2022). Monitoring agencies such as the IEA, in its global methane tracker, and the IMEO are incorporating these 'top- down' estimates in their work to validate and challenge data from other sources. Differences between top-down and bottom- up approaches are present and difficult to reconcile. Top-down methods tend to measure atmospheric methane concentrations using airborne or satellite sensors to infer emissions releases, while bottom-up approaches are based on activity data such as operational flows through a number of facilities, with standardised emission factors to estimate leakages from particular types of equipment. The IEA points out that typically bottom-up methods do not account for emissions from accidents and unpredictable process failures, which can constitute some of the largest emitting events. The coverage provided by satellites is still far from complete: existing satellites do not provide measurements over equatorial regions, offshore operations, or northern areas such as the main Russian oil and gas producing areas (IEA, 2022). Despite this, satellites are useful in identifying instances of massive methane emissions from 'ultra-emitters', often larger than 25 tons per hour of methane. Large short- duration releases from oil and gas, which are a mixture of leaks and intentional releases, are not captured in the current reporting system (CCAC, 2022). Independent monitoring and surveillance  IEA methane tracker The IEA methane tracker is a web-based information portal with the best available data and analysis on oil and gas methane emissions abatement potential. The headline statement from the press release for the IEA 2022 methane tracker assessment was that based on measurement campaigns and scientific