A massive underwater volcanic eruption in the South Pacific, climaxing in January 2022, is offering new hope for an “emergency brake” on climate change, after it surprisingly cleaned up its own methane release.
The volcano Hunga Tonga–Hunga Ha’apai lies 40 miles north of the Kingdom of Tonga’s main island, which was hard hit by a tsunami resulting from the 2022 eruption. Now, in a recent paper published in Nature Communications, researchers have identified an unexpected process where the eruption removed methane from the atmosphere, offering a possible tool to slow climate change.
Volcanic Evidence
Satellite data on the massive 2022 volcanic eruption provided researchers with important new information, revealing the presence of formaldehyde in the plume. This was noteworthy because formaldehyde results from intermediate stages of methane destruction, suggesting that the material was breaking down at an extremely rapid rate.
“When we analysed the satellite images, we were surprised to see a cloud with a record-high concentration of formaldehyde,” said first author Dr. Maarten van Herpen from Acacia Impact Innovation BV. “We were able to track the cloud for 10 days, all the way to South America. Because formaldehyde only exists for a few hours, this showed that the cloud must have been destroying methane continuously for more than a week.”
While prior research identified methane emissions during volcanic eruptions, never before has one been observed cleaning up its own mess. This could offer an important new technique to mitigate anthropogenic climate change.
Reviewing the Climate Change Data
The process at play here is a recent discovery, only coming to light in 2023, during analyses of Saharan dust storms. That research identified how dust blown from the Sahara would mix with salt as it drifted over the Atlantic Ocean, producing iron salt aerosols, which then converted into chlorine atoms when impacted by sunlight.
That airborne chlorine, in turn, would break down atmospheric methane, a surprising chain of events that restructured scientists’ understanding of tropospheric chemistry.
“What is new—and completely surprising—is that the same mechanism appears to occur in a volcanic plume high up in the stratosphere, where the physical conditions are entirely different,” said Professor Matthew Johnson from the Department of Chemistry at the University of Copenhagen, who worked on both discoveries.
The Hunga Tonga–Hunga Ha’apai event mirrored this, but instead of dust drifting over the ocean, the event’s force pushed large amounts of saltwater into the atmosphere alongside volcanic ash. Again, sunlight piercing the ash plume produced chlorine, which broke down the methane, as evidenced by the formaldehyde detections.
Halting Climate Change
While methane is far more potent than CO2, the leading cause of climate change, it breaks down much more rapidly—in just about a decade. In this balance, methane accounts for roughly a third of all global warming.
Given its short lifespan, reducing methane emissions would have a more immediate effect on climate change than reducing CO2, which persists longer. While CO2 reduction is a long-term goal, the relatively quick results have led some researchers to dub methane reductions as an “emergency brake” on climate change. The team says their findings could be an essential key to this new field of methane reduction research, although more work remains to quantify the rate of removal.
“How do you prove that methane has been removed from the atmosphere? How do you know your method works? It’s very difficult, said senior author Dr. Jos de Laat from the Royal Netherlands Meteorological Institute. “But here we address that problem by showing that methane breakdown can in fact be observed using satellites.”
“It’s an obvious idea for industry to try to replicate this natural phenomenon—but only if it can be proven to be safe and effective, “Johnson concluded. “Our satellite method could offer a way to help figure out how humans might slow global warming.”
The paper, “Satellite Quantification of Enhanced Methane Oxidation Applied to the Stratospheric Plume Following Hunga Tonga-Hunga Ha’apai Eruption,” appeared in Nature Communications on May 7, 2026.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.