Carbon dioxide usually dominates the discussion when it comes to climate change, but slashing methane emissions could have an even bigger effect on global warming over the next few decades. With the help of a satellite that is set to launch as early as 4 March from Vandenberg Space Force Base near Lompoc, California, governments and businesses will at last have a tool to help them to pinpoint methane hotspots on Earth and plug the leaks.

Developed by a coalition of environmentalists, scientists and aerospace engineers at a cost of around US$88 million, MethaneSAT is designed to provide an unparalleled view of methane emanating from oil and gas fields across the planet — as well as from agricultural facilities and landfills. Working with Google, MethaneSAT’s operators will process data from the satellite using an atmospheric model that can track methane in the air back to its sources on the ground. They will then make the data freely available. Google also plans to use artificial-intelligence algorithms to help map oil and gas infrastructure worldwide and identify where the pollution is coming from.

MethaneSAT will enable corporate and government accountability through “radical transparency”, says Steven Hamburg, chief scientist at the Environmental Defense Fund (EDF), an advocacy group based in New York City that led the satellite’s development. “This will be the first time that we have ever had this type of information for any greenhouse gas,” he says.

More than 80 times as potent as CO2 at trapping heat around Earth, methane is collectively responsible for around 30% of global warming since the Industrial Revolution. Methane lasts around 12 years in the atmosphere, whereas CO2 persists for centuries. This means that curbing methane emissions could have a notable cooling effect on global temperatures over the short term.

“We could basically cut warming nearly in half over the next couple of decades if we were to eliminate our methane emissions,” says Ilissa Ocko, an atmospheric scientist at EDF, whose research suggests that the oil and gas sector can reduce the bulk of its emissions at little to no extra cost1, for example by replacing leaky seals or broken valves. “In a lot of cases, fixing the problem is easy,” she says.
An audacious project

MethaneSAT has its roots in pioneering aircraft campaigns that helped to reveal the extent of pollution from US oil and gas fields roughly a decade ago. EDF subsequently worked with academics and those in industry on a series of studies that helped to document emissions across the United States, eventually showing that methane emissions from the oil and gas sector were 60% higher than official estimates2. On the basis of that work, the group then organized a team to design the satellite.

In 2018, EDF and its main scientific partners at Harvard University in Cambridge, Massachusetts, were awarded start-up money through the Audacious Project, a partnership involving the New York non-profit group TED, to develop MethaneSAT. If it succeeds, EDF will be the first environmental group to develop a satellite of such scientific calibre.

What sets MethaneSAT apart is its resolution. Commercial satellites already circling Earth can track major methane sources such as leaking wells and landfills. By contrast, a sensor aboard the European satellite Sentinel-5 Precursor can scan across vast landscapes and measure methane concentrations in the atmosphere, but without pinpointing emission sources. MethaneSAT operates in-between these two extremes, scanning wide swathes of Earth while also providing high-resolution measurements that can locate emitters big and small.

“We’re fitting into a place where nobody else is operating,” says Steve Wofsy, an atmospheric scientist at Harvard University, who is leading MethaneSAT’s technical team.
Having a moment

The spacecraft arrives during what many are calling a ‘methane moment’ for the planet. Last December, US President Joe Biden’s administration finalized regulations designed to slash methane emissions from the oil and gas sector by 80% by 2035. Other governments, such as those of European Union member states, are considering pollution standards for natural gas, meaning that they might impose fees on imports from producers that exceed limits on methane emissions. Industry is also stepping up with commitments: at last year’s United Nations COP28 climate summit in Dubai, for instance, 50 of the world’s largest oil and gas companies committed to eliminating methane emissions altogether by 2030.

“The capabilities of this satellite are phenomenal,” says Róisín Commane, an atmospheric scientist at Columbia University in New York City. But she points out that MethaneSAT is limited: each day, it can transmit imagery to Earth from only around 30 swaths of land measuring 200 square kilometres each. That is enough to accomplish its core mission of monitoring global oil and gas operations, as well as some agricultural sources, but Commane says that it will miss other scientific opportunities.

She has thus proposed putting sensors similar to MethaneSAT’s aboard a future NASA satellite, but with more power and a larger radio antenna. “There’s an awful lot more to be done,” Commane says.

For Wofsy, the big question is whether the data from MethaneSAT will actually push companies and countries to take action. Its operators hold sway over neither industry nor government, but the data showing the methane emissions will be out there in the public sphere, he says. “I hope it’s going to make a difference.”