New Satellites Revolutionize Detection of Methane Emissions

In a significant advancement for environmental monitoring, two satellites have been launched to track methane emissions from space. The Environmental Defense Fund's MethaneSAT, which was launched in March 2024, and the Carbon Mapper, a public-private partnership initiated later that year, are set to transform the way we identify and address methane super-emitters.

Methane is an exceptionally potent greenhouse gas, with a global warming potential that is 80 times greater than that of carbon dioxide in the initial two decades post-release. Over the past 200 years, methane concentrations have more than doubled, outpacing the increase of carbon dioxide. Alarmingly, current trends indicate that methane levels are rising more rapidly than at any time during the history of record-keeping.

Human activities are predominantly responsible for global methane emissions, contributing to more than 60% of the total. Key sources include fossil fuel extraction, livestock farming, waste disposal in landfills, and wastewater treatment processes. Fortunately, a small number of facilities are accountable for a large portion of these emissions. Approximately 5% of facilities are responsible for over half of the methane emissions in various oil and gas fields, which presents an opportunity to substantially reduce global methane pollution by targeting these super-emitters.

MethaneSAT and Carbon Mapper operate in a polar orbit, moving north-south around the Earth. As the planet rotates beneath them, they are able to monitor different potential emitting sites with each pass. MethaneSAT boasts a broad field of vision, capable of imaging areas as large as 15,000 square miles--comparable to the size of Glacier National Park in Montana. This capability allows it to identify methane hotspots effectively. In contrast, Carbon Mapper functions like a zoom lens, providing detailed images of individual sources at the scale of a football field, enabling the precise attribution of methane plumes to specific facilities and operators.

One limitation of both satellites is their reliance on sunlight for visibility. This dependency raises concerns that some operators in the oil and gas industry may attempt to conduct maintenance during nighttime hours, potentially evading detection. While the majority of industry operators are likely to comply with regulations, there is a risk that some may exploit this gap.

The advent of these satellites marks a pivotal shift in monitoring methane emissions. Unlike past incidents, such as the infamous 2015 Aliso Canyon gas leak in Los Angeles--which led to a massive settlement and was not reported for weeks--future leaks may not go unnoticed. In 2025, these satellites will have the capability to identify the largest methane emitters globally, even in remote locations where access is restricted, such as the Raspadskaya Coal Mine in Russia and the Qingshui Basin in China.

Within the United States, these satellites will also uncover super-emitters, potentially putting pressure on major corporations. Companies such as ExxonMobil and Chevron, along with their subsidiaries, may face scrutiny for their emissions in key regions like the Permian Basin in West Texas and the Bakken Oil Field in North Dakota. Operators of landfills, feedlots, and wastewater treatment facilities may also find themselves in the spotlight. With the capabilities of MethaneSAT and Carbon Mapper, there will soon be nowhere for the most significant methane polluters to hide.