Scientists discover volcano cloud destroyed methane for days after blast

A massive volcanic eruption in the South Pacific in 2022 may have partially cleaned up its own climate pollution, according to a new study published in Nature Communications.

Researchers found that the eruption of the Hunga Tonga–Hunga Ha’apai submarine volcano released around 330 gigagrams of methane — a potent greenhouse gas — but also triggered chemical reactions that destroyed large amounts of it in the atmosphere, according to Gizmodo.

The eruption sent nearly 2.9 billion tons of ash and gas into the air above the South Pacific. Scientists estimate the volcanic plume removed around 900 megagrams of methane per day over a 10-day period as it drifted toward South America.

“It is known that volcanoes emit methane during eruptions, but until now it was not known that volcanic ash is also capable of partially cleaning up this pollution,” first author Maarten van Herpen of Acacia Impact Innovation BV said in a statement.

Methane traps around 80 times more heat than carbon dioxide over a 20-year period and is believed to drive about 30% of global warming. Although methane naturally breaks down in the atmosphere within about a decade, scientists are searching for ways to accelerate that process.

Using the TROPOMI imaging spectrometer aboard the European Space Agency’s Sentinel-5P satellite, researchers detected unusually high levels of formaldehyde inside the volcanic cloud — a sign that methane was continuously decomposing.

The team believes seawater blasted into the atmosphere mixed with volcanic ash and sunlight to generate highly reactive chlorine atoms, which accelerated methane breakdown.

The findings could help scientists develop new technologies aimed at removing methane from the atmosphere, though major challenges remain in proving how much methane such methods can eliminate.

“How do you prove that methane has been removed from the atmosphere? How do you know your method works? It’s very difficult,” co-author Jos de Laat said in the statement. “But here we address that problem by showing that methane breakdown can in fact be observed using satellites.”

By Sabina Mammadli