Mapping the world’s biggest methane sources and tracking country response

Managed by IMEO, MARS transforms data into action. It’s the only open global system that detects super-emitters and is linked directly to a mechanism to engage stakeholders to eliminate them. Through MARS, UNEP notifies governments and companies to enable rapid response. 

Since launching three years ago, MARS has enabled over 40 mitigation cases around the world – a growing number that shows open data is a powerful tool for methane progress. Together, these sources released an estimated 1,200,000 tonnes of methane. These emission reductions are equivalent to the annual emissions of 24 million gasoline-powered cars.

These data tools exist to scale methane transparency. When the world can see exactly where the biggest methane sources are and whether governments are responding, it creates a powerful lever for progress.

The world’s top 50 methane emitters 

This data set presents the world’s 50 largest methane emitters detected by satellites across the oil and gas, coal and waste sectors. The ranking is based on a rolling six-month period to reflect recent trends, while also filtering out short-term fluctuations. 

Satellites detect only the largest methane emissions. While the top 50 emitters identified here account for a small share of the world’s total emissions, they represent major priorities for mitigation. 

The top 50 list is dynamic. This reflects, in part, the dynamic nature of industrial emission sources. Consider a gas flare that doesn’t burn properly. When it vents methane into the atmosphere, it could be a major source globally. But once it’s relit and burning properly, it will likely drop off the list. 

The top 50 list is also shaped by what satellites can see. That can shift over time in response to seasonal factors, such as variations in cloud cover. Satellite detection capabilities are limited over certain locations, including high latitudes, bodies of water and complex topologies like forests and mountains. As a result, some countries may have major methane sources that aren’t on the list simply because satellites can’t detect them. 

Download the top 50 emitters list and review the data dictionary here.

MARS country response rates 

This data product tracks how countries are responding to MARS alerts in the oil and gas sector and reveals where more progress is needed.

Previously, IMEO shared MARS’s global response rate. But this global average masked pockets of progress, with some countries achieving 100 per cent response rates, while others need greater engagement or support. The new country-level response rates offer a more nuanced view.

The response rate is calculated by dividing the number of emission sources for which IMEO has received a response by the number of sources for which MARS has issued an alert, over a rolling 12-month basis. 

Using a rolling 12-month period captures the most recent events – where emissions may still be ongoing – and ensures that the metric reflects progress where it matters most. These data are also provided with a two-month lag to allow stakeholders time to provide a robust response. This approach encourages countries to prioritize emissions with the greatest potential impact, rather than older detections that may no longer be active. It also helps highlight sustained commitment to working with MARS.

What does a response entail? 

Responding to a MARS alert requires countries and companies to investigate the root cause of the emissions and share information about the event, including whether operators have taken mitigation measures and, if so, what kind. 

These responses are critical, since satellite observations alone can’t confirm that emissions have ceased. Emissions could fall below satellite detection thresholds or an emission source could be intermittent. Confirming mitigation requires both satellite observations and complementary, on-the-ground information. 

Low response rates may not necessarily signal indifference. Some countries have only a few sources characterized as super-emitters, making a 100 per cent response rate more attainable than for countries with more emission sources. When it comes to response rate, context – the total number of notifications that a country receives – is crucial.

Low response rates could also point to countries that need more support. Some countries may not have teams trained to detect methane, while others face institutional barriers that prevent authorities from mandating a response from oil and gas companies. 

IMEO is working to address technical and institutional gaps through workshops to build knowledge and capacity, as well as partnerships with organizations including the International Energy Agency on guidance for responding to MARS alerts.

Download the response rate data and review the data dictionary here.

Explore the data 

Both data sets are available on Eye on Methane // GLOBAL and will be updated monthly. 

The best measure of these tools’ impact will be watching them change over time, for example when a country’s response rate ticks up with increased support or a landfill drops in the rankings – or off the top 50 list entirely – as mitigation progresses. These kinds of shifts will reflect real progress. 

Explore the data and join IMEO in building transparency for methane action.

Subscribe to monthly data updates to stay on top of the latest data releases on Eye on Methane // GLOBAL.

Learn more: