[2026-05-04] UNEP expands satellite methane tracking (MARS) to coal mines and waste facilities globally.

Overview

Methane from coal mines and landfills has long been one of the more inconvenient truths in industrial emissions accounting. Operators could self-report, regulators could accept those figures at face value, and the broader public had little means to independently verify what was actually escaping into the atmosphere. That dynamic has now changed. On 4 May 2026, the UN Environment Programme (UNEP) International Methane Emissions Observatory (IMEO) announced a formal expansion of its global Methane Alert and Response System (MARS) to cover coal mines and waste facilities. The announcement was made at a G7 Presidency event in Paris and represents a shift from satellite detection capability to operational alerting, meaning that when significant methane plumes are detected at these sites, formal alerts will now be issued and made available to regulators, investors, and the public.

MARS is not a new system. It has held detection capability across multiple industrial sectors for some time, and the oil and gas sector has been subject to its alerting framework for longer than coal and waste. What the 4 May 2026 announcement establishes is the operational formalisation of alerts for two sectors that have historically sat outside the most intense satellite scrutiny. For Australian environmental professionals advising coal mine operators, landfill managers, waste authorities, and infrastructure developers, this is a consequential change in the external risk environment. Independently verifiable, publicly accessible emissions data now exists overhead, whether site operators have accounted for it in their reporting or not.

The significance for environmental consultants, ESG advisers, and in-house counsel is hard to overstate. Australia operates significant coal mining sectors in Queensland and New South Wales, and manages hundreds of landfill facilities across all states and territories. Each of these sites now sits within the operational scope of an international satellite monitoring programme. The era in which fugitive methane emissions from these sectors could be characterised primarily through self-reported figures and generic emission factors is drawing to a close, and environmental professionals need to understand both the technical mechanics of MARS and the practical implications for their clients.

Key details of the MARS expansion to coal mines and waste facilities

MARS operates by processing data from a network of satellites capable of detecting methane plumes at the facility scale. The system draws on instruments including those aboard the European Space Agency’s Sentinel-5P satellite, which carries the TROPOMI (TROPOspheric Monitoring Instrument) sensor, as well as commercial satellites with higher spatial resolution. TROPOMI can detect methane concentrations at a horizontal resolution of approximately 5.5 kilometres by 3.5 kilometres, while newer commercial satellites such as GHGSat can resolve methane plumes down to individual facility components. When MARS detects a plume above a defined detection threshold, it generates an alert that is transmitted to relevant national authorities and, in many cases, made publicly accessible through the IMEO data portal.

The detection thresholds applied by MARS are not uniform across satellite instruments. TROPOMI-based detection is generally sensitive to emission rates above approximately 1,000 kilograms per hour from a single source, making it most useful for large, concentrated plumes. Higher-resolution commercial satellites integrated into the MARS network can detect emissions at significantly lower rates, depending on atmospheric conditions and instrument specifications. For landfill operations, this means that large, poorly capped cells with active decomposition releasing substantial methane flux are the most immediately exposed. For coal mines, surface ventilation shafts and goaf drainage infrastructure are the most likely sources of detectable plumes. Underground longwall operations in Queensland’s Bowen Basin and New South Wales’ Hunter Valley generate significant volumes of methane through ventilation air methane (VAM), and these represent exactly the type of point-source emission that operational MARS alerts are designed to capture.

Martin Krause, Director of the Climate Change Division at UNEP, stated at the Paris announcement that expanding MARS to coal and waste “sends a clear signal: the era of invisible methane emissions is ending.” That framing is precise. The system does not merely observe, it alerts. When a plume is detected, a notification is dispatched to the relevant national government body, giving that authority a defined period to respond and report on action taken. The response architecture is intended to create accountability between satellite observation and on-ground action, reconciling satellite data with on-ground mitigation in a way that previously allowed fugitive emissions to go unaddressed between reporting cycles.

The expansion aligns with broader international reporting principles that push high-emitting industries toward Tier 3 reporting methodologies, meaning direct continuous measurement rather than emission factors applied to activity data. The Oil and Gas Methane Partnership 2.0 (OGMP 2.0), which is an industry-government framework already operating under UNEP’s coordination, requires member companies to report methane at the facility level using source-level measurements. The MARS expansion signals that similar expectations will progressively be applied, formally or through investor and regulatory pressure, to coal and waste operators globally.

Australian context: NGER Act, state EPA oversight, and satellite methane alerts for coal and landfill operators

Australia’s primary federal framework for greenhouse gas reporting is the National Greenhouse and Energy Reporting Act 2007 (NGER Act), administered by the Clean Energy Regulator. Facilities above the threshold of

References and related sources

• Primary source: www.unep.org

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This is an iEnvi Machete news summary. Prepared by iEnvi to summarise the source article for contaminated land, groundwater, remediation, approvals and site risk professionals.

Published: 05 May 2026

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