OSLO, (Thomson Reuters Foundation) – As the world swelters through record temperatures, scientists say an unusual culprit may be partly to blame: an underwater volcanic eruption off Tonga in the South Pacific last year.
While most big blasts cool the planet with a sun-dimming haze, the eruption of Hunga Tonga-Hunga Ha’apai in January 2022 blew the equivalent of 60,000 Olympic swimming pools of water into the stratosphere, high above the planet.
Water vapour is a natural greenhouse gas, trapping heat as it swirls around the globe. By contrast, major land eruptions – such as Pinatubo in the Philippines in 1991 – temporarily dim sunshine with an ashen sunshade before falling back to Earth.