On 15 January 2022, the underwater volcano Hunga Tonga–Hunga Ha'apai erupted, unleashing a powerful tsunami that destroyed homes and caused four deaths throughout Tonga. Another lasting effect of this event — the largest underwater explosion ever recorded by modern scientific instruments — was the huge amount of aerosol and water vapor plumes it launched skyward.
Schoeberl et al. examined how Hunga's eruption affected climate in the Southern Hemisphere over the following 2 years. They found that in the year following the eruption, the cooling effect from the volcanic aerosols reflecting sunlight into outer space was stronger than the warming caused by water vapors trapping heat in the atmosphere. But most of the volcano's effects had dissipated by the end of 2023.
