If 142,000 tons of methane escape into the atmosphere above western Turkmenistan, and nobody is around to see it, did it really happen?
That is a hypothetical question, because someone did see it — from space.
While scanning for emissions from a mud volcano in a Balkan province in western Turkmenistan in January this year, a satellite controlled by a Canadian company called GHGSat noticed “an anomalously large methane plume” coming from a nearby gas facility and pipeline. It was the first time ever that a methane leak has been detected and confirmed from space, GHGSat said.
The breakthrough could herald a revolution in the way methane leaks from oil and gas facilities are detected, helping to stanch a major source of greenhouse gas pollution around the world.
GHGSat couldn’t explain what was causing that much methane to escape from the site, the Korpezhe oil and gas field. But it did estimate that the total volume of escaped methane over the period February 2018 to January 2019 was around 142,000 tons. The leak was equivalent to the greenhouse gas footprint of one million cars, or to the infamous Aliso Canyon methane leak that lasted for four months in California starting in late October 2015.
Invisible to the naked eye, methane leaks are a scourge that oil and gas companies around the world are under pressure to do something about. Methane is both a powerful greenhouse gas — it is dozens of times stronger than carbon dioxide as a heat-trapping gas, although it dissipates more quickly — and difficult to detect when it escapes into the air. So pervasive is the problem that the International Energy Agency (IEA) estimates total methane emissions from the oil and gas sector hit 80 megatons in 2017, or 6% of the energy sector’s global greenhouse gas emissions.
Monitoring for leaks is typically done on-site or, occasionally, by airplane. When groundwater corroded the metal lining of a well nearly 900 feet beneath the ground in California in October 2015, setting off the Aliso Canyon leak, an atmospheric scientist named Stephen Conley obtained the definitive measurements by flying a specially equipped airplane through the plume of methane over the site.
Conley says that methane detection from space needs to be done faster and more cheaply, but it has the potential to be a game changer. “[The] ability to detect leaks from space could be huge,” he said.
Airplanes outfitted with the right equipment can detect leaks at much finer levels of detail than satellites can — around 10 kilograms per hour rather than about 500 kilograms per hour at best for satellites, said Conley — but there are limits to what they can do. For one thing, many countries with extensive oil and gas operations might not allow emissions-detecting planes to enter their airspace. Satellites would hardly face such a prohibition.
The Turkmenistan leak was spotted by the Canadian company’s GHGSat‐D satellite and subsequently examined over a longer span by the TROPOMI satellite instrument, a bundle of equipment aboard another satellite. They are among the first of what could be a fleet of such space-based emissions detectors. For example, the non-profit Environmental Defense Fund is developing a satellite called MethaneSAT, while others are also in the works.
Ultimately, the most effective way to reduce methane leaks may come from a combination of solutions, said Greg Rieker, a professor at the University of Colorado, Boulder and head of the Precision Laser Diagnostics Laboratory.
“I think the true breakthrough is going to come from a stack of technologies – perhaps satellites catching very large, remote emissions in countries without regulation that requires periodic monitoring, but also very sensitive ground and near-ground systems that can pick up the bulk of the small, medium, and large emissions and differentiate between leaks and planned process-related emissions,” said Rieker.