In the quiet of space, a growing fleet of methane‑watching satellites now scans the planet for invisible plumes of climate‑heating gas. On the ground, those plumes are triggering a new kind of diplomatic and industrial conversation—one that could reshape how countries and companies tackle one of the most powerful drivers of global warming. At the heart of this shift sits the United Nations Environment Programme’s (UNEP) Methane Alert and Response System, or MARS, a satellite‑driven platform that is fast becoming a central reference point in the global debate over methane emissions.
MARS does something that has never been done at scale before: it spots major methane leaks anywhere on Earth, ties them to specific sites, and then sends alerts to governments and companies so they can act. As methane emissions continue to climb—despite a raft of climate pledges and a “global methane pledge” launched in 2021—the system is being held up as both a technical breakthrough and a test of political will.
What MARS actually does
MARS operates as the operational backbone of UNEP’s International Methane Emissions Observatory (IMEO), a data‑to‑action hub designed to turn methane measurements into concrete mitigation steps. The system integrates data from dozens of methane‑sensitive satellites, including high‑resolution instruments that can detect very large point‑source plumes, often in the oil and gas sector, at scales of roughly a ton or more of methane per hour.
When a satellite identifies a strong methane signal above a facility or hotspot, algorithms help attribute the plume to a likely source—such as a gas field, compressor station, or processing plant—and MARS then notifies the relevant government authorities and, where possible, the operating company. Authorities can respond with site inspections, repairs, or policy adjustments, and UNEP promises to make much of the data and follow‑up analysis publicly available weeks after detection, creating a feedback loop of transparency and accountability.
That “detect‑notify‑track” loop is what distinguishes MARS from earlier methane‑monitoring efforts. Instead of merely publishing static maps or academic reports, the system is explicitly built to push information into the hands of decision‑makers and to keep an eye on whether promises translate into pipe fixes, flare‑ups, and better waste‑management practices.
Why methane is suddenly so central
Methane may be less famous than carbon dioxide, but its role in near‑term warming is outsized. Molecule for molecule, methane traps far more heat in the atmosphere over a 20‑year window, and UN‑backed assessments estimate that methane is responsible for roughly a third of the global warming the planet has seen so far. That means curbing methane is one of the fastest‑acting levers countries have to slow the pace of climate change, even as the world continues to grapple with the long‑term decarbonisation of energy systems.
The latest global methane status reports show that human‑caused methane emissions are still rising since 2020, led by agriculture, fossil fuels, and waste sectors. Agriculture now accounts for about 42 percent of anthropogenic methane, with livestock and rice cultivation at the core; fossil‑fuel operations—including oil, gas, and coal—contribute roughly 38 percent, and waste industries, especially landfills and wastewater, add another 20 percent. Even with new policies and voluntary pledges, projections suggest emissions could be several percent higher by 2030 than they were in 2020 unless governments and companies deploy available abatement measures much more aggressively.
Against this backdrop, MARS is no longer just a technical experiment—it is a barometer of how seriously the world treats a “super pollutant” that can be cut relatively quickly with existing technologies.
From oil and gas to coal, waste, and beyond
Initially, MARS focused on the energy sector, particularly large methane pulses from oil and gas infrastructure. During its pilot phase, the system identified more than 600 significant plumes from energy‑sector facilities and formally notified stakeholders for over a hundred of them. That early work helped refine the way alerts are formulated, who receives them, and how MARS interacts with industry confidentiality concerns while still pushing for transparency.
Now the system is expanding its gaze. In 2024, IMEO and partner agencies flagged that MARS would be extended to coal mines and municipal‑waste sites, broadening the reach of its satellite‑driven alerts. By May 2026, UNEP had announced that MARS was being rolled out across coal and waste sectors worldwide, after satellite data highlighted, for example, a major Indian landfill among the world’s largest methane‑emitting sites.
This expansion matters because many of the world’s fastest‑growing methane sources sit in these sectors. Coal mines steadily leak methane as seams are drilled and coal is extracted; landfills, especially in rapidly urbanising regions, decompose organic waste and generate methane unless modern gas‑capture systems are installed and maintained. MARS can now point to specific coal mines or waste dumps, alert national regulators, and eventually help track whether new capture infrastructure or operational changes are actually reducing emissions on the ground.
India and the weight of “survival emissions”
For India, MARS’ evolution comes at a delicate moment. The country is now recognised as the third‑largest methane emitter globally, with roughly 31 million tonnes emitted in 2020, or about 9 percent of the world’s total. Within that, agriculture dominates, especially enteric fermentation in livestock and rice cultivation, which together account for the bulk of India’s methane profile.
Experts within India’s own policy ecosystem describe much of this as “survival emissions”—activities carried out by small and marginal farmers that underpin food security for hundreds of millions of people. This raises a hard question: how can a country meet methane‑reduction targets without penalising the poorest producers or jeopardising food supplies?
At the same time, India also faces rising emissions from coal mining and waste management. Landfills around major cities, many of which still lack proper gas‑capture systems, are increasingly visible in satellite imagery. When a landfill in India shows up as one of the planet’s top methane hotspots, MARS alerts are not just a technical report card; they become a signal that India’s rapid urbanisation has not yet been matched by a commensurate waste‑management overhaul.
For policymakers in Delhi and state capitals, MARS thus embodies both a challenge and an opportunity. It can help identify where the biggest leaks lie—whether in coal‑belt mines or metropolitan dumpsites—and guide investments in leak‑repair programmes, gas‑capture infrastructure, and better agricultural practices. But it also forces a conversation about how India balances its climate obligations with energy security and rural livelihoods.
A test of transparency and accountability
One of the most striking aspects of MARS is how rarely receiving countries and companies actually respond in detail. A UN‑backed snapshot of the system’s early operation found that of more than 1,200 major methane plumes flagged globally, less than 1 percent of cases included proper follow‑up information explaining the cause and what was being done to fix it. That gap between detection and documented action underscores a simple truth: technology can reveal the problem, but it cannot by itself force solutions.
To address this, IMEO has begun rolling out a “MARS Response Blueprint,” a set of guidelines aimed at helping countries build internal response frameworks—identifying which agencies own which data, how to verify emissions, how to engage operators, and how to track mitigation progress over time. The blueprint is not legally binding, but it does shift the conversation from “we didn’t know” to “here is how we are expected to respond.” In a world where climate‑pledge gaps are widely documented, MARS is becoming a tool to measure whether those pledges are being translated into verifiable action.
UNEP’s “MARS” System Turns Global Methane Tracker into a Climate Wake‑Up Call
