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How satellites could help hold countries to emissions promises made at COP26 summit

‘This is becoming real,’ one scientist says. ‘It is real. And it’s super exciting.’

An illustration of the European Space Agency’s Sentinel-5P satellite, which was launched in 2017 to provide information on atmospheric gases that affect air quality and climate. (Photo illustration by Pierre Carril/European Space Agency)
8 min

GLASGOW, Scotland — On a recent day inside the sprawling conference center where United Nations climate talks are taking place, a small crowd gathered to hear a panel with an intriguing title: “The Space Race to Save the Planet.”

It wasn’t, despite the name, a tale of science fiction. Rather, the event was about satellites and the promising ways that scientists are using them to track greenhouse gas emissions in the atmosphere.

“If you had told me this a decade ago, you could have knocked me over with a feather,” Riley Duren, a University of Arizona research scientist and engineering fellow at NASA’s Jet Propulsion Laboratory, said of the boom in emissions-monitoring satellites.

“This is becoming real,” he said. “It is real. And it’s super exciting.”

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Previously, scientists were forced to rely largely on estimates of greenhouse gas emissions, based on formulas that take into account the burning of fossil fuel and industrial and agricultural activities, among other contributors. But the proliferation of satellites is further enabling measurements of greenhouse gases in the air, around the globe. That’s helping to pinpoint emissions sources and to hold countries and corporations accountable for their climate promises.

“There’s an old cliche that I’m sure you’ve heard a million times: that you can only manage what you can measure,” former vice president Al Gore said at an event on the sidelines of the COP26 climate summit. Gore is behind Climate Trace, a coalition of nonprofits and academic institutions using satellite imagery and machine learning to bring what he told The Washington Post will be “a new regime of radical transparency.”

The halls of COP26, as might be expected, are peppered with new innovations that promise to help combat climate change. There’s a hydrogen-powered ambulance on display, not far from the world’s first electric two-seat Formula racecar. There are technologies aimed at making farms more sustainable and others to help reduce food waste.

But both here and outside in the real world, satellites are increasingly seen as a critical tool to locate, measure and disclose the extent of greenhouse gases in the atmosphere. Governments have launched them and have plans to launch more. Private companies and advocacy groups are pursuing the new frontier, too, as are data analytics firms focused on interpreting vast amounts of atmospheric information.

At its pavilion inside the summit, Japan has a display on the half-dozen satellites its space agency maintains to observe land, ocean and atmospheric changes.

The European Space Agency also used the summit as a chance to showcase the “unprecedented” insights its satellites are already providing about the planet, including reams of data about greenhouse gases in the atmosphere.

“Earth observation is playing a key role in enabling the international community to determine the progress made toward the [Paris] agreement,” the agency said.

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The ever-growing number of sentinels in the sky — with more in the pipeline — has begun to offer revealing glimpses into the sources and scale of greenhouse gas pollution. One key example: methane.

“Our world is rapidly becoming a place in which methane emissions will have nowhere to hide,” Columbia University researchers wrote in October 2020 in a paper detailing the fast-moving push to more accurately monitor emissions from space and to make it tougher for those emitting greenhouse gases to shield them from public view.

In particular, the group wrote, the “poor grasp of methane emissions appears likely to become a thing of the past.” The report found that over the next five years, new satellite systems, in concert with measurements taken from airplanes and ground-based monitors, “can increase markedly the transparency surrounding methane leakage.”

Those planes and monitoring systems on the ground have been helpful in taking measurements within countries and regions. But satellites offer a far more holistic picture.

“If this were a truly local or regional or national problem, you wouldn’t necessarily need a satellite to do this,” said Mark Brownstein, senior vice president of energy at the Environmental Defense Fund advocacy group. “The satellite becomes important because it allows you to gather data efficiently and routinely on a global scale.”

Some methane-detecting satellites act like wide-angle lenses, sweeping around the globe day after day and gathering massive amounts of data that can help scientists flag significant sources of the climate-warming gas.

The most prominent example is the European Space Agency’s Sentinel-5P, which was launched in 2017. The hexagonal device, weighing in at nearly 500 pounds, relies on solar wings in orbit. It circles the globe 14 times a day from 500 miles above the surface, continuously taking measurements of a 1,600-mile swath of the Earth’s surface. It covers the entire surface of the Earth roughly twice a month, providing key information on a range of atmospheric gases that affect air quality and climate.

Other satellites act more like a telephoto lens, able to zoom in on a more granular level to pinpoint emissions from particular facilities. One company pioneering that approach is Canada-based GHGSat, which in January launched the second in a fleet of 10 high-resolution satellites it plans to eventually have in orbit.

“We’re literally seeing individual sites,” including a single coal mine or gas well, the company’s chief executive, Stephane Germain, said in an interview with The Post this year.

That sort of close-up view can help the company’s customers, which include oil and gas companies, identify and repair existing methane leaks. But it also can help offer regulators more visibility into sites in need of oversight.

At the COP26 event, Germain added that the private firm recently released a collection of its data from its first five years in operation.

“It starts to show some pretty alarming trends,” Germain said. “We have seen, just in the last year, dramatic acceleration in emissions of methane from oil and gas, and a dramatic acceleration in emissions of coal. … The patterns are very clear.”

The proliferation of satellites is set to continue at a dizzying pace over the coming years.

In 2022, after years of planning and construction, EDF plans to launch MethaneSat, a system able to identify methane emissions across a broad geographic area, as well as measure leaks at predetermined locations. The group says the satellite will be able to regularly monitor regions that account for more than 80 percent of global oil and gas production and quantify the emissions rate of specific sources of methane.

In April, California announced Carbon Mapper, a public-private partnership with NASA’s Jet Propulsion Laboratory and the Earth observation firm Planet that plans to launch satellites into orbit to track emissions of greenhouse gases. Duren, who is in charge of the project, says he believes it will help fill in gaps in knowledge and lead to actionable information about specific sources — from landfills and dairy farms to leaky oil and gas wells.

The U.S. government also has plans to step up monitoring. This spring, President Biden announced a NASA-led effort to collect more-sophisticated climate data in coming years. NASA already has plans in 2024 to launch the Geostationary Carbon Observatory, or GeoCarb — a satellite that will be perched 22,000 miles above the Americas and will collect millions of daily observations about concentrations of carbon dioxide, methane and other gases.

It is not just the physical satellites that have led to more insight into the world’s emissions, but also more-sophisticated analyses of the data they collect.

The French firm Kayrros, for example, has used data from Europe’s Sentinel-5P to spot methane “super-emitters” in different parts of the globe — including a massive, leaking landfill in Bangladesh and a startling methane plume over gas fields in Alberta, Canada, and Appalachian coal mines.

Less than a decade ago, “you had no clue where the methane was coming from,” Antoine Halff, Kayrros’s chief analyst and co-founder, told The Post. “Now, it’s really night and day. … The technology is a game changer.”

He and others acknowledge that plenty of work remains and limitations exist.

Cloud cover can thwart satellite measurements. And no one device covers every corner of the Earth all the time, potentially allowing large but intermittent leaks to go undetected. The surveillance system, for now, also remains a patchwork of sorts, but one that is quickly improving.

“There is no Swiss army knife to solve this problem; these sources are so different,” Duren said at the Glasgow panel. “You need different observing systems to be able to get the whole elephant.”

But with each passing year, scientists are doing more to bring the elephant into view and to provide what EDF’s chief scientist, Steven Hamburg, calls “policy-relevant” data that leaders cannot ignore.

“That isn’t to say the technology is totally there, but over the last few years, it’s gotten so much better,” said Hamburg. “In two years, it will look different than it does now. The revolution is ongoing and rapid.”

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