Methane is responsible for around 30% of the rise in global temperatures since the Industrial Revolution, and rapid and sustained reductions in methane emissions are key to limiting near-term warming and improving air quality.

Two key characteristics determine the impact of different greenhouse gases on the climate: the length of time they remain in the atmosphere and their ability to absorb energy. Methane has a much shorter atmospheric lifetime than carbon dioxide (CO2) – around 12 years compared with centuries – but absorbs much more energy while it exists in the atmosphere.

Methane also affects air quality because it can lead to ground level (tropospheric) ozone, a dangerous pollutant. Methane leaks can also pose explosion hazards.


Atmospheric concentrations of methane are on the rise

The concentration of methane in the atmosphere is currently over two-and-a-half times greater than its pre-industrial levels. The increase has accelerated in recent years, and preliminary data indicate that there was another significant annual increase in 2022.

Estimates of methane emissions are subject to a high degree of uncertainty, but the most recent comprehensive assessment – provided in the Global Methane Budget – suggests that annual global methane emissions are around 580 Mt. This includes emissions from natural sources (around 40% of the total) and from human activity (around 60% of the total), also known as anthropogenic emissions.

The largest anthropogenic source is agriculture, responsible for around one quarter of emissions, closely followed by the energy sector, which includes emissions from coal, oil, natural gas and biofuels.

Sources of methane emissions, 2022

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Better and more transparent data are needed but should not stand in the way of mitigation action

There are large differences between data based on measurement campaigns and scientific studies, and the emissions levels reported by official public bodies, such as to the UN Framework Convention on Climate Change (UNFCCC), which rarely make use of direct measurements. This mismatch exists at both global and national levels and for all sources of emissions. Many official greenhouse gas submissions to the UNFCCC have not been updated for years, and, even for those that have, many of these inventories are not yet accurate enough to provide a clear picture of emissions.  

Global methane emissions reported to the UNFCCC and estimates from the IEA, 2022

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Methane emissions can be estimated in a number of ways. Bottom-up approaches can use activity data (e.g., the number of facilities or the extent of operations) multiplied by standardised emission factors (e.g., default values or leak rates for particular types of equipment). Top-down methods tend to measure atmospheric methane concentrations, normally by airborne or satellite sensors, to infer emission releases.

Estimates are subject to significant uncertainty over the magnitude of emissions sources and their variability. Some of the largest emitting events are the result of accidents and unpredictable process failures and these might contribute a large level of emissions from oil and gas operations, but these are often not included in bottom-up inventories. Tried and tested approaches are already available for lowering methane emissions, but better and more transparent data will help to facilitate targeted action.


The growing evidence base and the International Methane Emissions Observatory

Incomplete information about actual emissions levels and a lack of awareness of the cost-effectiveness of abatement is a key barrier to reducing methane emissions. In response, a growing number of recent initiatives aim to measure and report current and historical emissions from facilities, production types and countries. Yet these assessments remain incomplete – most countries and regions still have little or no measurement-based data and the data they provide often require careful processing. These gaps highlight the need for robust and transparent data evaluation and harmonisation of estimates.

The International Methane Emissions Observatory (IMEO), established by the UN Environment Programme with support from the European Union, is an initiative that aims to commission measurement studies and to integrate measured data from a range of sources. This includes company reporting through the Oil and Gas Methane Partnership 2.0 Framework, direct measurements from peer-reviewed studies, satellite observations, and national inventories. These empirically verified data will be provided in a public dataset to inform companies, governments, investors, and civil society as they work together to track methane emissions levels and abatement efforts. The IEA strongly supports IMEO and maintains an ongoing dialogue with the Secretariat and the Scientific Oversight Committee.

In 2022, IMEO launched the Methane Alert and Response System, a global system connecting satellite methane detection to transparent notification processes in order to promote on-the-ground emissions mitigation efforts. This system aims to identify major emissions events, activate its partners to notify relevant stakeholders, and support and track progress toward mitigation. Satellites detected more than 500 very large leaks from fossil fuel operations in 20 countries. A small portion of these were from coal, likely because coal mine methane emissions are often diffuse and therefore harder to detect.

Satellite-detected large leaks from fossil fuel operations, 2022

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Satellites are providing a major boost to our understanding of emissions

Advances in monitoring technologies, notably from satellites, have been a key to boosting our understanding of the level and nature of methane emissions. Current satellites and data processing techniques can be used to detect and quantify total emissions from major leaks over a large area, down to small leaks at the facility level. They also enable regional estimates of total methane emissions over longer periods of time.

New satellites are being developed that will provide higher resolution, greater coverage, and have more sensitive detection thresholds. These include instruments such as GHGSat, EnMAP, Carbon Mapper, SBG, CHIME and EMIT and MethaneSAT that aim to deliver high-resolution images for selected high-priority areas. These will improve methane quantification capabilities, raise public awareness and support regulatory oversight.

Satellite technologies are not perfect. They can struggle to provide readings in many environments such as offshore areas, mountain ranges, snowy or ice-covered regions, and at high latitudes. Satellites are also impaired by cloud cover, even if only a portion of the monitored area is covered, limiting the number of days when detections can be made. For example, countries with dense forests or in equatorial regions, such as Nigeria or Venezuela, are very often cloudy, hindering observation efforts.

Data from the European Space Agency satellite Sentinel-5P, processed by the earth analytics firm Kayrros, indicates that during 2022 there were around 70 countries where methane emissions from oil and gas operations could have been detected for at least 15 days. Large emission events were observed in 20 of these countries in 2022. Coverage tended to be best in the Middle East, parts of Central Asia and Australia, where it was possible to make a direct observation every 3-5 days. On the remaining days, cloud coverage or other interference prevented observations from taking place. Accounting for the level of satellite coverage, observed very large leaks are estimated to have emitted around 3 Mt of methane from oil and gas operations in 2022 (6% of our estimate of oil and gas emissions in the 20 countries where events were detected).

New technology development has allowed satellites to detect methane emissions in offshore areas for the first time in 2022, but this has not yet become part of routine monitoring efforts, and there is still a high degree of uncertainty over estimates derived from satellite readings of emissions from offshore events. Emissions from the Nord Stream pipeline explosion were one of the first offshore leaks to be quantified using satellite data. A working paper from the International Methane Emissions Observatory estimates emissions from this event were between 75 and 230 thousand tonnes of methane.

Detection of methane emissions from the Nord Stream leak

Satellite Detected Methane Emissions From The Nord Stream Leak

GHGSat (2022), Global emission monitoring.

Satellites are also uncovering large methane emissions from coal mines, with several detections in Russia, the United States and other coal producing regions. Sentinel-5P detected around 0.2 Mt of emissions from such events in 2022 (2% of our estimate of coal mine methane emissions in the seven countries where events were detected) and more than 1 500 methane emissions events were observed at coal mines by GHGSat (GHGSat can detect events larger than around 100 kg per hour while Sentinel-5P can detect emissions events larger than around 5 tonnes per hour). High-resolution satellites are also beginning to provide new insights on other potential sources of emissions with around 10 leaks detected at LNG liquefaction facilities in 2022.

Other detection and measurement campaigns will remain vital, and the optimal system will combine satellite measurements with drone-based and other aerial surveys, ground-based sensors and surveys, and continuous monitoring devices. Reporting and verification procedures and systems are also essential.

A detailed picture of methane emissions is necessary to design policy tools that can drive deeper cuts in an efficient manner through market-based instruments, performance standards and trade measures. Robust monitoring, reporting and verification can also facilitate the work of regulators in verifying compliance and in tracking progress against reduction targets; it can support regulatory development; and enable other stakeholders to engage with methane mitigation efforts.


Methane emissions from the liquefied natural gas industry

Methane leaks can occur along the liquefied natural gas (LNG) value chain and there is increasing evidence that they could be a small but important source of emissions. Leaks can occur at liquefaction facilities from gas service valves, reciprocating compressors, pump seals or metering equipment as well as during the transfer of LNG from the facility to the ship. During shipping, methane leaks can also occur if “boil-off” gas (a small fraction of the LNG cargo that evaporates) is vented or is used as propulsion and not fully combusted in the ship’s engines.

Based on detailed data on global LNG trade and the sample of satellite readings of LNG liquefaction facilities from GHGSat, we estimate total fugitive methane emissions from LNG liquefaction and shipping in 2022 to be around 0.4 Mt, equivalent to around 0.1% of total annual LNG transported globally. Shipping makes up the majority of emissions and the main route to reduce associated methane is by ensuring that boil-off gas is injected into engines or reliquefied rather than vented. Manufacturers are increasingly promoting technologies that reduce methane slip (gas that is not fully combusted in ships’ engines), for example by recirculating exhaust gases, using high-pressure direct injection or methane oxidation catalysts.


The IEA Global Methane Tracker is our effort to provide a coherent set of estimates for the energy sector based on the best available data

The IEA produces and publishes country-level estimates for energy-related methane emissions and abatement options as part of our IEA Global Methane Tracker. This data tool also includes the latest emissions estimates from non-energy sectors – waste and agriculture – based on publicly available data sources, to provide a fuller picture of methane sources from human activity.

Marginal abatement cost curve for methane from fossil fuel operations, 2022

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Our estimates are regularly updated using the best available data on fossil fuel operations, country- and production-specific emissions intensities, measurement campaigns and large emissions events detected by satellites. We also work with IMEO to ensure our estimates reflect the latest findings from measurement-based, peer-reviewed studies. Recent studies are improving our understanding of methane emissions from LNG supply, biogas production, incomplete-combustion in flares, the sources of oil and gas methane, different sectors in China, oil and gas emissions in Canada and the United States, and coal facilities in Australia and many other regions.

With fossil fuels, methane emissions can occur at any point during production, processing and transport. In addition to these emissions, we include emissions from the end use of coal, oil products and natural gas in the Global Methane Tracker (3 Mt or 3% of energy-related methane). This estimate is based on the emissions factors published by the Intergovernmental Panel on Climate Change for energy consumption in homes, industries and in the transport sector. Some measurement campaigns have suggested that these emissions factors could significantly underestimate actual emissions across different end-use environments, including in industry, cities and households. These are areas with very high levels of uncertainty and our estimates will continue to be updated as the evidence base grows.

Emissions from abandoned coal mines and oil and gas wells are not included in the Global Methane Tracker. Existing measurements cover a limited number of facilities and regions, and reliable data on abandoned mines and wells is not available for most countries. These sources could, nonetheless, represent significant levels of emissions. The U.S. Environmental Protection Agency indicates they are responsible for close to 5% of energy-related methane in the United States; and a recent study estimated that abandoned mines could account for almost one fifth of methane emissions from worldwide coal production.

The IEA Global Methane Tracker 2023 is our best attempt to reconcile existing information and produce a consistent set of country-level estimates. Further details on the methods used can be found in the Global Methane Tracker Documentation. We recognise these estimates do not represent the last word. We welcome all feedback based on measurement campaigns and robust data sources that can further refine our estimates. Relevant reports or scientific studies can be shared with IEA analysts by email at MethaneTracker@iea.org.