International Efforts for the Abatement of Methane Emissions in the Energy Sector

1  The importance of methane as a greenhouse gas

The abatement of methane emissions has long become a focal point of endeavours for the achievement of set climate goals. Methane (CH₄) is counted among the greenhouse gases (GHG), which trap heat in the atmosphere and contribute to global warming. It is the second most abundant GHG after carbon dioxide (CO₂) (1). In order to compare the effect of different GHGs on global warming, the important factors besides their concentration in the atmosphere are how long they last in the atmosphere and the degree of their impact on it. For the comparison of the impact on global warming, the metric of the global warming potential (GWP) is primarily used. The GWP describes the effect per tonne in relation to the effect of 1 t of CO₂ over a period of 100 years (GWP100), which is given in CO₂ equivalents (CO₂e). (2)

The GWP of CH₄ according to the sixth Assessment Report (AR6) by the International Panel on Climate Change (IPCC) for a time period of 100 years is 27 to 29,8 t CO₂e. It needs to be considered that the GWP of CH₄ for a period of 20 years is 79,7 to 82,5 t CO₂e, since CH₄ is near-term climate forcer with a life time in the atmosphere of about twelve years compared to the CO₂ life time of several centuries. The GWP for CH₄ has been updated over time to account for new scientific knowledge and data about changes in the composition of the atmosphere. The updated GWPs are provided by the IPCCs Assessment Reports. Because for the definition of goals as well as ongoing comparable reporting a consistent set value is needed, the commonly used GWPs are usually from previous Assessment Reports. The EU currently uses a GWP of 25 t CO₂e based on the fourth Assessment Report (AR4). From 2024 going forth a set GWP of 28 for CH₄ will be used for greenhouse gas inventories based on the fifth Assessment Report (AR5). (3)

The short life time and high GWP of CH₄ are the basis for the contribution of methane emission abatement to the achievement of climate goals, since these abatement measures provide a comparatively near-term way to influence global warming.

Compared to pre-industrial levels the atmospheric concentration of CH₄ is two-and-a-half times higher. The International Energy Agency (IEA) provides an estimation of global methane emissions in the Global Methane Tracker 2023 of 580 Mt with expected further increase. With a GWP100 of 28, this equates to 16,2 bn t CO₂. This contains methane emissions from both natural and anthropogenic sources. Up to about 60 % of the total global methane emissions are anthropogenic (ca. 348 Mt or 9,7 bn t CO₂). In general, anthropogenic emission sources are attributed to the sectors agriculture, energy and waste with further subdivisions. The agricultural sector is the largest of these sources of anthropogenic emissions. The energy sector is a close second with nearly 40 % of human attributed emissions (Figure 1). (4)

Fig. 1. Natural and anthropogenic methane emission sources by sector in Mt CH₄ (4). // Bild 1. Natürliche und anthropogene Methanemissionsquellen nach Sektoren in Mt CH₄ (4).

In all relevant sectors continuous efforts are made to develop and implement measures for the abatement of methane emissions. The following section will go into more detail for the energy sector.

2  Methane emissions in the energy sector and approaches for abatement

The IEAs Global Methane Tracker 2023 estimates the methane emissions of the energy sector at almost 135 Mt for the year 2022. As shown in figure 2, the most relevant industries in this context are the fossil fuel operations, oil, gas and coal, which viewed individually each account for around 40 Mt of the energy sector’s emissions. (4)

Fig. 2. Methane emissions in the energy sector 2000 to 2020 in Mt CH₄ (4). // Bild 2. Methan-Emissionen im Energiesektor 2000 bis 2020 in Mio. t CH₄ (4).

The energy sector has a significant potential for methane emission abatement through using well-known technologies and procedures. An important general approach in this area is the implementation of regulations and obligations for monitoring and reporting. Measures to reduce methane emissions in the sectors can be attributed to three types of emissions: fugitive, vented and flaring (5). Venting and flaring are planned procedures. Venting refers to the release of unburned CH₄ into the atmosphere through designed mechanisms and can be unavoidable, e. g., in case of a disruption of operations. Flaring describes the intentional combustion of CH₄ for the purpose of its disposal via appropriate mechanisms and is used as an alternative to venting. Ideally flaring converts the CH₄ to CO₂ and water, with the combustion efficiency to be considered. In this case, methane emissions result from incomplete combustion or unlit flares. (6)

Fugitive emissions are unintentional and undesirable outlets of CH₄, usually resulting from leakage. In the oil and gas sectors LDAR (leak detection and repair) programs can be a valuable contribution to the reduction of leakage related gas emissions. LDAR programs are aimed at detecting leakages early on, most commonly via infrared cameras, and initiating repair work. LDAR programs can be applied across the supply chain and also used for continuous monitoring through the use of installed sensors (Daily LDAR). (5)

Significant opportunities for the reduction of methane emissions in the coal sector are available through the installation and improvement of gas drainage operations. CH₄, which is released due to coal mining operations is referred to as coal mine methane (CMM). Gas drainage is mainly used in underground coal mines for the pre-drainage of coal seams before extraction to mitigate the risk of the formation of explosive gas and air mixtures. Ideally, energy recovery is implemented for the methane-rich drained gas, dependant on technical and economical factors. Keeping up gas drainage in former mining areas represents an essential measure to mitigate the emissions of coal mine CH₄ from abandoned mine sites, which can continue to emit gas from former mine openings as well as natural and anthropogenic pathways (5). The ongoing gas drainage following the closure of the last German hard coal mine in the year 2018 in the Ruhr area, e. g., has prevented based on data by the Bezirksregierung Arnsberg 1,9 Mt CO₂e (GWP100 25) of methane emissions by the usage of drained mine gas for energy recovery in 2022 (7). Despite gas drainage systems being primarily used in underground coal mining, the example of the North Antelope Rochelle mine in Wyoming shows the successful application of a degasification program to a surface mine (8).

A further factor regarding abandoned mines, but also inactive oil and gas wells, is the development of targeted data collection and provision. Emissions from abandoned mines are usually not considered in estimates and scenarios. This is due to measurement studies for mine sites as well as information regarding the mines often being limited in general or available for a comparatively limited number of regions only. According to estimates of the U. S. Environmental Protection Agency (EPA) emissions from abandoned coal mines amount to over 10 % of the CMM emissions of the USA. Improving the data availability in this area therefore is a significant contribution to data acquisition regarding methane emissions in the energy sector. (5)

3  Overview of international efforts for the abatement of methane emissions

Methane emissions have become a focal point of international observations with regards to the mitigation of GHG emissions. Furthermore, during the last decade several institutions and initiatives has been launched, which are aimed at methane emissions specifically. An important aspect when looking at international efforts is that there is no uniform global approach for the planning and implementation of measures. The implementation of specific abatement measures is done on a national level or project-related. CH₄ abatement measures on an international level can be attributed to three categories:

1. Information: Data collection, processing and provisioning as information source.
2. Support: Assisstance in planning and implementation of measures.
3. Obligation: Binding objective agreements and regulations.

These categories will be further elaborated on based on examples hereafter.

3.1  Base data and information provisioning

This category contains the collection, processing and provisioning of data as an information source for further measures. An important aspect in this regard is the improvement of available data and data transparency.

When looking at different sources of data, like measuring campaigns, scientific studies and official reporting, differences in between the data sets can become apparent. Among the causes for the differences are predominantly the methodology for the estimation of emissions, different degrees of measurement-based data in the inventories, updates of inventories and adoption of corresponding reporting standards (5, 9). This is illustrated in figure 3 by comparing estimates of the IEA and data reported to the UNFCCC of methane emissions for the year 2022 by source.

Fig. 3. Comparison of emission estimates for 2022 from reports to the UNFCCC and estimates of the IEA in Mt CH₄ (4). // Bild 3. Gegenüberstellung von Emissionswerten für 2022 aus Berichten an die UNFCCC und Schätzungen der IEA in Mio. t CH₄ (4).

The improvement of data transparency, increase of measurement-based reporting and the integration of different sources of emission data to develop and provide data sets is a key part in supporting and enabling targeted strategies for emission abatement. These factors are the core focus of the International Methane Emission Observatory (IMEO), which was launched in 2021 by the UN Environment Program (UNEP). IMEO collects and processes emission data from multiple sources. The integrated data set serves as information basis for decision makers as well as for the tracking of emission abatement progress. The emission data contains reporting, scientific studies and satellite data. The improvement of measurement-based reporting is based on furthering the use of the 2020 established Oil and Gas Methane Partnership 2.0 (OGMP 2.0) framework for MRV (Measurement, Reporting and Verification) by the UNEP. (9)

In general, the methods of approach to estimating methane emissions are bottom-up and top-down. The bottom-up approach uses activity-based data, like the number, type and scale of operations, and specific emission factors for the respective emission sources in the sectors. Differences regarding the used emission factors, nationally as well as in comparison to other countries, can lead to larger deviations in the reported emissions for a sector (4, 10). Furthermore, large unanticipated emissions, like leaks, are often not properly accounted for in this approach (4). The top-down approach for the estimation of methane emissions regards measurement-based data. Several different types of measured data are available. These include ground-based measuring, ice core data, aircraft-based measuring and satellite data (10). For the development of reports and assessments as well as projections and scenarios, like the Global Methane Assesssment of the Climate and Clean Air Coalition (CCAC) and UN Environment Programme (UNEP) or the IEA’s Global Methane Tracker, results from both approaches are considered and integrated (5, 10).

Satellites are a relatively new source for the detection and measuring of methane emission. An advantage of satellite data is the capacity for larger spatial coverage in detecting methane emissions and providing global measurements. But it has to be considered, that weather conditions and interferences can affect the measuring and that not all regions can be observed to the same degree (5, 10). Still satellite-based measurements are an important contribution to the detection of methane emissions and improvement to data base accuracy. The year 2022 marked the launch of the Methane Alert and Response System (MARS) of the IMEO. It is a satellite-based system for the detection and attribution of larger CH₄ flares. The aim, besides the detection and attribution, is the further monitoring of the CH₄ flares as well as data transmission for planning and implementation of corresponding measures. The experiences and results of the initial phase will be reported by the 28th climate conference 2023. (11)

3.2  Support and advancement of abatement measures

The support and advancement of measures to abate methane emissions include, beside possibilities for financial support, providing project-relevant information and experience to improve the planning and implementation of measures. This contains, e. g., training opportunities, reporting framework like the OGMP 2.0, consulting and guidelines to develop and implement new policies (9, 12, 13). A clear differentiation from the previous data provisioning regarding the activities of different institutions and the scope of measures is not always the case, since they are often not limited to the collection, processing and provisioning of emission data, like the IMEO’s training series for CH₄ regulators and company staff and sharing of best practises. Regarding initiatives which specifically aim at the support of methane emission abatement projects, the Global Methane Initiative (GMI), e. g., supports the development and implementation of policies, technical and financial feasibility assessments of projects, project application and training regarding CH₄ recovery and emission mitigation. (12)

A contribution of the IEA shows an example of guidelines for the planning and implementation of policies. „Driving down Coal Mine Methane Emissions: A Regulatory Roadmap and Toolkit” presents lessons learned in different jurisdictions regarding designing and establishing new policies and regulations for CMM. Derived from this is a ten-step guide from understanding the setting in a legal and industry profile context as well as estimates of the CMM emissions, over the corresponding design of the policies and regulations, to implementing and establishing. Furthermore, the guideline contains the regulatory toolkit, which showcases considerations and approaches regarding the content of regulations. (13)

3.3 Target agreements and regulations

This category regards the definition of shared targets and legislations. The most important legally binding, international targets for emission reduction are currently determined in the Paris Agreement, which entered into force in 2016 and is the successor to the Kyoto Protocol. In article 2 of the treaty the main goals are described. The increase in the global average temperature is to be kept well below 2 °C regarding pre-industrial levels. Furthermore, efforts to limit the increase in global average temperature to 1,5 °C regarding pre-industrial levels are to be pursued. The mitigation of GHG is essential to achieving these goals. (14)

The Global Methane Pledge (GMP) is an initiative established in 2021, which aims at reducing anthropogenic methane emissions to achieve the climate targets of the Paris Agreement. The participants commit to collectively reduce the global anthropogenic methane emissions across all sectors until 2030 by at least 30 % regarding 2020 levels. (15, 16)

The EU proposal for a legislative act to reduce methane emissions in the oil, gas and coal sectors is an example for legal regulations. The EU Climate Law, which was developed following the European Green Deal and entered into force in 2021 defines the binding climate targets of the EU as net zero GHG emissions by 2050 as well as a net reduction of at least 55 % of EU GHG emissions compared to 1990 levels (17). The “Fit for 55 Package” as part of the European Commission’s work program (2021) focuses on a wide range of approaches to achieve the Climate Law’s targets. Legislative proposals are intended for the oil, gas and coals sectors. (18)

The proposed legislation contains obligation for monitoring and reporting including reporting intervals for the oil and gas sectors and coal mine sites. Venting and flaring of CH₄ is to be prohibited except in cases of emergency or malfunctions. Closed and abandoned underground mines and inactive wells are to be registered, measuring equipment installed and monitoring conducted. The operators in the oil and gas sectors will be required to develop LDAR strategies with corresponding reporting. (1, 6)