New Sources Emerge for Tracking Methane Emissions by Satellites

Illustration: Marcelle Louw for GIJN

Headlines continue to underscore that methane is a major contributor to global warming. Methane is roughly 80 times more potent than carbon dioxide at trapping heat in the atmosphere over the first 20 years after it is emitted. And methane is responsible for about one-quarter of human-made global warming.

Because cutting methane emissions can make a major impact on global warming, increased attention is given to measuring it, to facilitate reductions. And satellite imagery can help journalists identify methane emissions from different sources, including petroleum extraction and transmission, coal mining, and landfills.

Several updates and new sources have emerged since the 2022 publication of GIJN’s investigating methane guide, which includes a short version and a multi-chapter long version.

We focus here on “top down” emissions tracking from satellites, but “bottom up” ground observations are also important methods for tracking methane (and both are covered in chapter two of the GIJN guide). Another important policy development involves governments considering how to regulate methane emissions and what should be disclosed about emissions. Get a sense of this activity in this Reuters overview, but also look for developments to follow locally.

Five New Sources

Earth Surface Mineral Dust Source Investigation (EMIT) is a new resource from NASA, the US National Aeronautics and Space Administration. The portal “shows high-confidence research grade methane plumes from point-source emitters — updated as they are identified.” Clicking on the red circles will show the time and concentration of the emissions.

GHGSat Spectra reveals a selection of major emissions worldwide, although not with pinpoint accuracy and with a time delay of several weeks. (Sign-up is required for access.) On the Spectra map, click in the upper right on the “Analytics From” box to change the dates of data shown. Click the triangles on the map to see details on each release. See “?” for more information. Spectra cautions: “Whilst we can see methane concentrations, it is not possible to use the map to identify specific sources of methane.” GHGSat is a company that sells more detailed information, hence its offers to “upgrade to SPECTRA Premium,” which a spokesman said, “would range from the tens to the hundreds of thousands of dollars depending on coverage and options selected.”

SRON shows methane emission plumes worldwide. It is produced by the Netherlands Institute for Space Research. The map is updated about every week and shows approximate source locations, but the resolution is low. A chart shows the locations by longitude and latitude (not the country). This presents a bit of a challenge, but putting the coordinates into Google Maps will show the location. Or try other coordinates converters.

Image: Screenshot, SRON

SATALERT shows methane concentration levels, searchable by date. The map shows area-wide levels, not linked to specific sources. There is more background about how to use SATALERT, the creation of Australian researcher Dan Moss. By choosing different time periods, it’s possible to distinguish between intermittent high concentrations of methane, such as a large emission on one day, and a lower but steady concentration release. The images that SATALERT uses come from the EU’s Sentinel-5P satellites and have a resolution of 7.5-by-5 kilometers (4.65-by-3.1 miles) per pixel, which limits identification of specific facilities. However, to go deeper, SATALERT uses Sentinel 2 data for 20-meter resolution. Moss encourages reporters to contact him.

Chasing Methane from IndiaSpend is that country’s first methane tracker and monitors emissions in India across various sectors. Data gathered between January and September 2022 shows emissions from landfills in cities including Mumbai, Pune, and Bengaluru. The nongovernmental organization contracted with a private company to analyze data from EU satellites. The plan is to update the site monthly.

Also watch for scientific research on methane emissions. For example, this study describes “carbon bombs,” or potential fossil fuel resources whose use would result in substantial methane and carbon dioxide emissions. An environmental group, LINGO, extracted data from the study about what it similarly termed “methane bombs,” broken down by country.

Finally, there are commercial sources for emissions information based on satellite images. They sometimes provide information for free and offer discounts to journalists. Commercial providers include Geofinancial Analytics and Kayrros.

Kayrros recently released data on major emissions to the Guardian, which did an extensive article: Revealed: 1,000 super-emitting methane leaks risk triggering climate tipping points. A Kayrros spokesperson said reporters could request the database, which has country-by-country information, and will be updated quarterly. Reporters also could ask for additional information about emissions in their countries.

Still on the Horizon

Several other sources are poised to start providing data.

NASA announced in December 2022 that observations from the EMIT and other NASA science instruments will be part of a global survey of point-source emissions of methane from solid waste sites such as landfills. The multi-year effort is being developed and conducted by the US nonprofit consortium Carbon Mapper. A Carbon Mapper official said, “We will be looking to release a more formal timeline for the project in April [2023].” They have plans to launch their own methane-sensing satellites later in 2023.

MethaneSAT is being developed by a subsidiary of the Environmental Defense Fund (EDF), a US-based NGO. MethaneSAT will not provide data until mid-2024. However, measurements using similar spectrometers aboard aircraft flying over limited areas may start in early 2023.

Global Methane Hub, SRON, and GHGSat: Announced in November 2022, this joint project is focused on landfills around the world, but no data is yet available as of early 2023.

Methane Alert and Response System (MARS): This international methane tracking effort, run by the UN Environmental Programme, will start issuing data in the second half of 2023, according to officials. But information will not be made public until 45 to 75 days after the detection on an emission. This gap will allow IMEO to consult with the emitters. In 2022, MARS officials provided images to journalists about 2022, but this practice appears to have ended. See more on MARS in the video below.

Accessing Images Directly Is Possible

Much of the underlying emission data comes from EU satellites, particularly the Sentinel-5P satellite operated by the European Space Agency.

Sentinel-5P images are public. Downloading them is possible from the Sentinel Hub EO Browser. However, familiarity with handling satellite images is necessary. Attention needs to be paid to the timeframes involved, the resolution of the images, and the measurement of the methane volumes.

Images from the Sentinel-5P satellite are available to the public. Image: Screenshot, European Space Agency

IndiaSpend chose to rely on an expert consultant, Respirer Living Sciences, which used Sentinel-5P images and the EU’s CAMS Emissions Inventory data to identify methane emissions sources and map it to Indian cities.

For a deep dive into the strengths and weaknesses of the different satellites see this article (and many links) by the non-partisan nonprofit organization RMI. In 2023, RMI issued a report and Satellite Point source Emissions Completeness Tool (SPECT), which seeks to help users understand and assess satellite “completeness” for identifying and tracking super-emitters of methane.

Methane Remains a Key Climate Change Contributor

The International Energy Agency (IEA) estimated in its 2023 Global Methane Tracker report that emissions from the energy sector rose slightly last year to 135 million tons, just below the record set in 2019. The energy sector contributed 40% of human-generated methane emissions in 2022, second only to agriculture.

The IEA also concluded that oil and gas companies are not doing enough to cut methane emissions, despite methane cuts being among the cheapest options to limit near-term global warming. According to the IEA, 75% of energy-related methane emissions can be eliminated with available technologies at a cost of US$100 billion.

New studies point out methane emissions sources that have gotten less attention, such as sewage treatment plants.

A final note: In the US, the EU, and other regions, debates are underway about national policies on curbing methane emissions. These are worth exploring and understanding by any journalists investigating methane.

Additional Resources

GIJN’s Guide to Investigating Methane — A Key to Fighting Climate Change

Climate Change Accountability: GIJN’s Guide to Investigating Methane

Journalists’ Guide to Using AI and Satellite Imagery for Storytelling

Toby McIntosh is a senior advisor for GIJN’s Resource Center, which provides online resources to journalists worldwide. He was the editor of FreedomInfo.org, (2010-2017) a nonprofit website based in Washington, D.C. that covers international transparency laws. He was with Bloomberg BNA for 39 years and has filed numerous US Freedom of Information requests and has written about FOI policies worldwide. He is a steering committee member of FOIANet, a network of FOI advocates.