Satellites accurately detect methane emissions in large-scale test

Researchers Adam Brandt, Josh Romo, and Taylor Adams set up a meteorology station during preparations for controlled methane releases. Image: Frances Reuland

Monitoring the harmful and potent greenhouse gas using satellites could help slow global temperature increases

Researchers have conducted the largest-ever controlled test of space-based methane monitoring, helping to detect super-emitters of the planet-polluting gas.

‘There has been significant scepticism over the years about whether methane tracking really works because it’s a challenging technical problem to detect the gas from space,’ said senior study author Adam Brandt. ‘Our results should give regulators, policymakers, producers of methane, and the general public a lot of confidence moving forward.’

The study, published in Nature, found that dedicated methane sensors can correctly detect nearly all methane plumes released on clear days.

To reach their conclusions, researchers timed 481 methane releases at a Stanford research site in Casa Grande, Arizona, to overpasses by 11 government, non-profit and commercial satellites through 2025. Fifteen research teams across nine countries then independently analysed the observations, assessing whether each satellite image showed a methane plume and how much of the gas was released.

They compared with the known releases. Under ideal conditions, with few clouds and moderate wind, the satellite instruments reliably detected plumes when methane flowed at rates of about 50–200 kilograms per hour.

Methane Gas Fire High Flare Stack Flaring Tower Platform in Refinery Petroleum Plant or Flame Burn On Offshore Oil Extraction Process. — During its first 20 years in Earth’s atmosphere, methane is 80 times more potent than carbon dioxide at trapping heat. Image: Quality Stock Arts/Shutterstock

Satellite monitoring systems detect methane using infrared light reflected off Earth’s surface, so they can struggle to detect plumes through clouds.

‘This poses problems in some key methane-emitting regions,’ the authors write, ‘including tropical oil and gas producers Nigeria and Venezuela, as well as cold, cloudy climates like Canada and Russia.’

Methane is the world’s biggest driver of climate change after carbon dioxide. While carbon dioxide lasts longer, methane is 80 times more potent at trapping heat during its first 20 years in Earth’s atmosphere.

In 2023, the oil and gas sector accounted for about 78 million tonnes of anthropogenic methane emissions worldwide, making the industry a major source of this planet-polluting gas.

In 2022, the UK signed a global methane pledge to collectively reduce global methane emissions by at least 30 per cent by 2030, compared with 2020 levels. In the UK alone, methane represented 14 per cent of the total greenhouse gas emissions in 2022, with the main sources originating from agriculture, waste and the fuel supply sectors.