The 2022 eruption of the Hunga Tonga Hunga Haapa submarine volcano blasted approximately 2.9 billion tons of ash and gas into the South Pacific. Notably, researchers found that while the eruption released about 330 gigagrams of methane—more than the annual emissions of 2 million cows—it simultaneously destroyed about 900 megagrams of methane each day through chemical reactions within the plume. This process, observed for 10 days as the plume drifted toward South America, highlighted volcanoes’ potential role in mitigating their own methane emissions.
Methane is a potent greenhouse gas, contributing to approximately 30% of global warming. Although it breaks down within about 10 years in the atmosphere, some emissions come from natural sources, like volcanic eruptions. This study, published in Nature Communications, revealed high concentrations of formaldehyde in the plume, indicating ongoing methane decomposition.
Researchers believe that reactions within the volcanic ash, similar to those involving Saharan dust, facilitated the breakdown of methane through sunlight-induced chlorine atoms. This mechanism could be leveraged to develop new strategies for reducing atmospheric methane levels, such as creating reactors to extract methane or using controlled atmospheric releases of chlorine.
Accurately measuring methane reduction remains a challenge, but satellite data can help validate these methods. The researchers encourage further exploration of chlorine atoms as potential methane scavengers, addressing the urgent need for innovative solutions as global warming accelerates.
