When the Hunga Tonga–Hunga Ha’apai volcano erupted in 2022, it released a staggering 2.9 billion tons of ash and gas into the South Pacific. Surprisingly, this eruption also had a surprising side effect: it helped clear some of its own pollution.
A recent study found that the eruption emitted around 330 gigagrams of methane, equivalent to what over 2 million cows produce annually. Yet, in a fascinating twist, the ash plume managed to destroy about 900 megagrams of methane daily, equal to the daily emissions from another 2 million cows. Even more astonishing, this cleanup continued for 10 days as the cloud drifted toward South America.
Maarten van Herpen, the study’s lead author from Acacia Impact Innovation BV, remarked, “While it’s known that volcanoes emit methane, it was surprising to find that the ash could also help reduce this pollution.”
Methane is a powerful greenhouse gas, trapping around 80 times more heat than carbon dioxide over a 20-year period. It’s estimated to contribute to about 30% of global warming. Fortunately, methane doesn’t linger long in the atmosphere, usually breaking down within about 10 years.
Beyond industrial sources, methane also comes from natural events, including volcanic eruptions. To combat methane emissions effectively, researchers are studying methods to quicken its natural breakdown.
The study revealed a potential new method for this. By using the TROPOMI imaging spectrometer aboard Europe’s Sentinel-5P satellite, scientists detected high concentrations of formaldehyde within the volcano’s plume. This compound forms when methane breaks down. Notably, formaldehyde stayed at elevated levels for over a week, indicating ongoing methane reduction.
Van Herpen’s previous studies showed that when Saharan dust crosses the Atlantic, it interacts with seawater to create aerosols. Sunlight catalyzes reactions that lead to chlorine atoms, which speed up methane breakdown. A similar process might occur in volcanic plumes, where seawater and ash mix and react under sunlight.
Overall, these findings may guide new strategies for methane reduction. Researchers are considering designs for reactors that could extract methane from the air, utilizing chlorine-rich brine or other solutions. However, potential environmental impacts from direct chlorine release are still a concern.
One major challenge is accurately measuring how much methane these methods remove. Jos de Laat, a co-author and senior scientist, highlighted the difficulty: “How can you prove that methane has been removed from the atmosphere? With satellites, we can observe changes, which is promising.”
As global warming progresses, innovative methods for reducing methane emissions will become crucial. The research suggests that understanding nature’s solutions could inspire engineers to develop effective, safe strategies to combat climate change. For more on methane’s role in climate change, check out the EPA’s overview.
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atmospheric science,Chemistry,Global warming,methane,Volcanic eruptions
