When Hunga Tonga–Hunga Ha‘apai (HTHH) erupted in January 2022, it shot the standard volcanic cocktail of ash, gas, and pulverized rock into the sky. But the eruption included one extra ingredient that’s now causing climate concerns: a significant splash of ocean water. The underwater caldera shot 146 metric megatons of water into the stratosphere like a geyser, potentially contributing to atmospheric warming over the next 5 years, according to a new study published in Nature Climate Change.
Earth’s average temperature is teetering on the edge of surpassing its preindustrial level by 1.5°C—the target set by the United Nations in the Paris Agreement. In May 2022, the World Meteorological Organization announced there was a 50% chance of exceeding the 1.5°C threshold over the next 5 years. The new study showed that slight warming caused by the HTHH eruption increased the likelihood of Earth temporarily tipping past that mark by another 7%.
