Researchers studying the 2022 Hunga Tonga-Hunga Ha'apai eruption found that volcanic ash and salt spray created a chemical reaction that destroyed methane in the stratosphere. This process produced formaldehyde as a byproduct, suggesting a natural mechanism for breaking down one of the most potent planet-heating gases. While the discovery offers a theoretical blueprint for geoengineering to reduce atmospheric methane, scientists warn that replicating this process in the lower atmosphere could have unpredictable effects on ecosystems and air quality.
