MARS Frequently Asked Questions

Methane emissions from human sources (including the energy, waste and agricultural sectors) drive about 30% of today’s global warming. Because methane is a short-lived but powerful greenhouse gas, with over 80 times more warming potential than CO2, emission reductions now can deliver immediate climate progress and buy us time to pursue broader decarbonization.

Reducing methane emissions also carries significant benefits for public health, economic livelihoods and energy security. 

A report from the International Energy Agency, UNEP and the Climate and Clean Air Coalition finds that in the fossil fuel sector alone, where reductions are overwhelmingly cost-effective and readily available, targeted action could avert nearly 1 million premature deaths from ozone pollution, 90 million tonnes of crop losses and about 85 billion hours of lost labor from heat exposure by 2050—all while providing roughly USD 260 billion in direct economic benefits.

The Methane Alert and Response System (MARS) is a data-to-action platform set up as part of UNEP’s International Methane Emissions Observatory (IMEO) mission to put open, reliable and actionable data into the hands of those who can reduce emissions. 

MARS takes advantage of a wealth of satellite imagery/data to scan the globe for major emission sources and alerts countries and companies so that they can take methane action and accelerate progress. In doing so, MARS supports the implementation of the Paris Agreement and Global Methane Pledge.

Through MARS, notifications of detected emissions events are shared directly with governments and, if possible, facility operators who are members of UNEP’s Oil and Gas Methane Partnership 2.0 (OGMP 2.0). 

Governments may nominate focal points to receive MARS notifications directly from IMEO. Alternatively, the notification is shared with the UNEP Permanent Representative. Facility operators that are members of OGMP 2.0 will also receive notifications directly from IMEO. More information on the notification process is below. 

MARS brings together four critical components to drive transparency and enable emission reductions: 

1. Detection of large sources of human-caused methane emissions.
2. Notification of relevant countries and companies about these detected emissions.
3. Response from notified stakeholders to address the emissions.
4. Tracking progress of actions taken to reduce emissions and collaboration to prevent future methane emissions.

MARS is the first global system that provides actionable and transparent data from satellites, directly enabling governments and companies to credibly reduce their methane emissions and drive progress to limit the rise of global temperatures.

MARS plays a unique role by drawing data from nearly a dozen satellite instruments and providing it in an accessible and actionable form. The system leverages UNEP’s global reach across governments, civil society and the private sector to put this data in the hands of stakeholders who can use it to drive down methane emissions.​

MARS was announced at the 27th United Nations Climate Change Conference in November 2022 and began its initial pilot phase in January 2023. The pilot phase presented an opportunity for UNEP’s IMEO to engage with partners, countries and operators to refine MARS processes and procedures before making data public.

MARS became operational on December 1,2023.  Data is available at: https://methanedata.unep.org 

At COP29 in November 2024, IMEO announced the Eye on Methane, where MARS notifications can be viewed, will offer increasing levels of detail and functionality.

Currently, the focus of MARS is on detection and alert of emissions in the oil and gas sector, with the goal of eventually incorporating additional methane-emitting sectors as detection technologies improve.

Any questions about MARS data or process should be directed to unep-mars@un.org

MARS combines the capabilities of satellites with a broad view of emissions across a large area with high-resolution satellites that can monitor methane emissions down to a small area on the ground. This enables a “tip-and-cue” approach.

1. Regions of Interest (ROIs) are determined through:
   1. Averaging observations from lower-resolution satellites like TROPOMI, GOSAT/GOSAT-2 or MethaneSAT, which cover much of the globe on a daily basis, to identify “hotspots.” These are regions of higher methane concentrations that indicate emissions from one or more significant sources.
   2. Analyzing individual methane plumes detected from a non-targeted, continuously observing satellite instrument such as TROPOMI, Sentinel-2, Landsat or EMIT.
2. Once a ROI is determined, UNEP’s IMEO will do one or more of the following:
   1. Search available high-resolution satellite records for recent emissions from the ROI.
   2. Search available high-resolution satellite records for indication of long-term emissions from the ROI.
   3. Target high-resolution satellites, such as PRISMA and EnMAP, to look at the ROI to find current emissions.
3. After a ROI has been investigated once, MARS utilizes deep learning models to monitor data from continuously observing high-resolution satellites for future emissions from the region.
4. Notifications are sent to governments and companies once high-resolution satellites can locate emissions at the facility-level. These notifications may be “batched,” meaning they may contain emissions from one or more facilities over a recent time period.

More information on the satellite methodology can be found here.