The massive eruption of the undersea volcano off Tonga was in all likelihood the strongest in three decades. Now the eruption turns out to be the driver of climate change.
The January 2022 eruption of the Hunga Tonga-Hunga Ha’apai submarine volcano in the South Pacific is likely to become the global warming booster. This is the result of a study in the journal “Nature Climate Change”. The eruption increased the probability of exceeding the 1.5 degree temperature increase by seven percent.
The Tonga eruption is one of the best-documented such events in human history, write the scientists led by Stuart Jenkins from the University of Oxford (UK) in the study published on Thursday. It is estimated that the eruption ejected 146 megatons of water vapor and around 0.42 megatons of sulfur dioxide into the stratosphere.
Most volcanic eruptions mainly heave sulfur dioxide into high layers of air. The researchers write that this leads to a cooling of the temperature, because the aerosol particles scatter sunlight. Over several years, however, it is possible that the Tonga eruption will have the opposite effect.
After volcanic eruption in the Pacific: Here a tsunami wave hits Tonga(00:54)
Volcanic eruption as a driver of climate change
This is due to the high water vapor emissions, which have increased the water content in the stratosphere by 10 to 15 percent. Water vapor acts as a greenhouse gas. So if the vapor stays there for a long time, it leads to an increase in the surface temperature on Earth. Since the eruption on January 15, 2022 also emitted relatively small amounts of sulfur dioxide, which counteract the increase in temperature, the volcanic eruption could become a driver of climate change – at least for a limited period of time.
The scientists’ analyzes refer to the fact that the global average temperature has exceeded the pre-industrial level by 1.5 degrees Celsius. According to the calculations, the chance that the world will experience its first year in which this mark is actually exceeded in the next five years will increase by around seven percent as a result of the consequences of the Tonga eruption. But that doesn’t change the fact that by far the strongest driver of this development remains man-made greenhouse gas emissions, the researchers write in the study.