Somewhere above the planet right now, satellites are scanning oil fields, pipelines, and gas infrastructure — detecting vast plumes of methane that no ground crew would ever spot. When they find one, an automatic alert goes out, free of charge, directly to the government responsible for that territory.
The system has been running since 2023. Governments are receiving the notifications. But as of 2025, roughly 88% of those alerts are going unanswered.
A system built to catch what was once invisible
MARS — the Methane Alert and Response System — was launched in 2023 by UNEP’s International Methane Emissions Observatory (IMEO) as the first global, free satellite-based alert system for major methane emission events. It combines satellite data, scientific expertise, and artificial intelligence to pinpoint large leaks and send direct notifications to the governments and companies responsible for those sites.
The potential benefits of acting on those alerts are real and varied. Swift responses can reduce gas waste, boost domestic energy sales, improve national energy security, and cut local air pollution. More broadly, MARS gives governments a concrete, data-driven tool for meeting national emissions reduction targets — something that was simply out of reach before satellite monitoring reached this level of precision.
Two years in: a widening gap between alerts and action
Since MARS launched, government engagement has grown — but the numbers remain stark. As of 2025, only around 12% of MARS notifications globally have received a response. Nearly nine in ten alerts are going unanswered, even as the infrastructure to deliver them functions exactly as designed.
That low engagement rate reveals something important: receiving an alert and acting on one are still very different things for most governments. The gap isn’t primarily about awareness. It points to deeper structural barriers — unclear legal authority over operators, insufficient staffing at regulatory agencies, and no standardized process for translating a satellite notification into a coordinated mitigation response.
A five-step playbook for governments that want to act
To address this, the IEA and IMEO have jointly developed a five-step sequential framework. The steps: receive and classify the alert; notify the relevant operator; allow the operator to respond; verify and follow up on that response; then review and document the full event. Each step carries a defined role and a recommended timeframe.
Three urgency levels are assigned based on emission rate and whether the source is recurrent. Level 1 events — the largest and most frequently detected — must complete all five steps within 30 days. Level 2 events have a 60-day window, Level 3 events 90 days. Within those windows, individual steps carry their own sub-deadlines, with the earliest actions required within 24 to 72 hours of receiving the alert.
The framework is non-binding. It’s designed as an adaptable guideline, not a regulatory mandate — one that countries can shape to fit their own legal, operational, and financial contexts. The goal is to give governments a workable starting point rather than a rigid prescription.
What makes a response actually work
Effectiveness depends on more than following a checklist. One of the framework’s core requirements is that designated MARS focal points — the officials assigned to receive and act on alerts — must have clear legal authority to compel operators to respond, share data about emission events, and implement mitigation measures. Without that authority, the process stalls at step two.
Adequate resourcing matters just as much. Competent authorities need staff and tools to follow up at each stage; a framework that exists on paper but can’t be executed in practice offers little real-world benefit. Maintaining an open dialogue with IMEO also plays a role. If a government or company implements a mitigation measure, IMEO can confirm whether it actually worked — a feedback loop that turns the process into a learning system rather than a one-way notification. Because IMEO publicly reports which notifications received responses and whether mitigation succeeded, there’s a reputational dimension too: governments that engage can demonstrate credible climate action.
Technical help is available — but governments must reach out
Neither the IEA nor IMEO expects governments to navigate this alone. Both organizations offer direct technical assistance to governments and companies seeking to implement the framework or better understand how MARS works in practice. The guidance document itself is built on lessons from countries that have already responded successfully to MARS notifications — evidence that the system can work when the right structures are in place.
The path forward will likely depend on how many governments move from passive recipients of alerts to active participants in a global methane response system. As satellite coverage improves and public reporting on response rates becomes more visible, the pressure to act — and the tools to do so — will only grow clearer.
