https://edition.cnn.com/2026/05/30/climate/hunga-tonga-volcano-eruption-methaneA volcano that erupted in the South Pacific in 2022 destroyed some of its own methane emissions, and scientists now think the chemistry behind it could become a new tool against one of the most potent planet-heating gases.
The Hunga Tonga-Hunga Ha'apai eruption on 15 January 2022 was one of the most violent of modern times, hundreds of times more powerful than the Hiroshima bomb, with a sonic boom that circled the planet twice. New research published in Nature Communications found that it also cleaned up after itself.
Studying satellite data, scientists spotted a huge cloud of formaldehyde, a gas that forms when methane is broken down. "We found a huge cloud of formaldehyde that should normally not be there", said study author Maarten van Herpen. They tracked it for 10 days, and since formaldehyde lasts only a few hours, the methane destruction must have continued for over a week.
The eruption blasted enough salty water vapour into the stratosphere to fill around 58,000 Olympic-size swimming pools. Sunlight hitting that salty mixture appears to have produced chlorine, which reacted with methane and broke it down, the same process previously observed when Saharan dust blows over the Atlantic. The team estimates the eruption produced around 330,000 tons of methane, of which roughly 900 tons were destroyed each day.
Why it matters: methane is about 80 times more effective at trapping heat than carbon dioxide over 20 years and accounts for roughly a third of global warming. Because it is short-lived, cutting it could slow warming relatively quickly. The findings raise the possibility of injecting iron-based particles into the air over the ocean to mimic the effect.
Independent scientists are cautious. Pete Edwards of the University of York called the results interesting but "very difficult" to confirm, warning of "potential unintended consequences on climate, air pollution and ecosystem health". Emily Dowd of the University of Leeds said the chemistry still needs thorough testing in atmospheric models before anyone counts on it.