For the first time ever, a major leak of the highly potent greenhouse gas methane has been detected from space in the UK.
Its satellite detection raises hope that future losses can be stopped more quickly.
Methane has 28 times the warming potential of CO2 and is a major contributor to global warming.
In energy terms, the gas leaked over the three months before it was stopped could have powered 7,500 homes for a year.
The leak from an oil pipeline in Cheltenham, revealed exclusively to the BBC, was discovered in March.
It was detected by the University of Leeds with the help of specialized satellites.
Methane, a greenhouse gas, is responsible for about 30% of global temperature increases.
Emily Dowd, PhD researcher at the School of Earth and Environment and the National Center for Earth Observation, University of Leeds, has used satellite imagery to assess methane leaks from landfill sites. But she noticed on the images the distinctive sign of a methane leak a few kilometers away, coming from a pipeline owned by Wales and West Utilities.
Methane has 28 times the global warming potential of carbon dioxide in 100 years.
Identifying and tackling methane emissions is a crucial objective of the UK and other countries seeking to tackle climate change.
After discovering the leak, Dowd teamed up with GHGSat – whose satellites provided the original images – to make further detections from space, while a team from Royal Holloway University took round measurements on the ground.
Dowd said: “Finding this leak leads to the question of how many are out there and maybe we need to look a little harder to find them and take advantage of the technology we have.”
Wales and West Utilities said they became aware of the leak after a member of the public reported the smell of gas. They said they were obtaining the necessary permits to replace the gas mains when the leak was detected by satellite.
But the satellite detection process has demonstrated the potential to quickly locate methane leaks.
The main sources of methane are the oil and gas industry, agriculture and landfills. Methane emissions in the UK have fallen significantly since 1990, but progress has slowed in recent years.
Currently methane leaks are detected through routine field investigations – a very challenging prospect when there are thousands of kilometers of pipes and sites. And the UK’s methane emissions are just an estimate drawn from data on economic activity.
Jean-Francois Gauthier, senior vice president for strategy at GHGSat, told the BBC: “It’s important to emphasize that satellites are only one piece of the puzzle. But satellites have a very unique value… that they can go back to.” [and collect more images] very frequently and they can do it without the need to deploy people on the ground, so they can do it effectively and economically.”
The company has nine satellites in its constellation, which orbit at 500 km altitude, and are some of the highest resolution devices capable of seeing gases with a resolution of 25 m.
The company recently signed a £5.5 million partnership with the UK – funded by the British Space Agency – to provide satellite data on methane emissions to UK organizations such as Ordnance Survey.
British Space Agency chief executive Paul Bate said: “Satellites are becoming smaller and more powerful, giving us an ideal vantage point from which to monitor global greenhouse gas emissions and inform decision-making on the path towards Net Zero”.
There are still limitations with the satellites that will need to be developed.
Professor Grant Allen, professor of atmospheric sciences at the University of Manchester, told the BBC: ‘There is still work to be done to fully validate the precise magnitude of such emissions estimated by satellites such as GHGSat, but the capacity is already proving extremely useful in identifying where large (preventable) sources may be located.”