“Tonga’s Underwater Volcano Eruption in 2022 Could Push Global Temperatures Above 1.5C Threshold, New Research Reveals”

The eruption of Tonga’s underwater volcano in 2022 has raised concerns about global temperatures rising and potentially exceeding the 1.5C warming threshold. A new study published in Nature Climate Change has found that the eruption of the Hunga Tonga–Hunga Ha’apai volcano in Tonga released an unprecedented amount of water vapor into the atmosphere, which could lead to a temporary increase in global surface temperatures.

The eruption, which occurred on 15 January 2022, was one of the most violent eruptions in recent history, ranking a six on the volcanic explosivity index. The eruption sent ash, gas, and water vapor high into the atmosphere, with the plume reaching a record height of 57km. The eruption also triggered tsunami waves that reached as far as Russia, the US, and Chile, impacting around 84% of Tonga’s population and resulting in two fatalities.

Unlike typical volcanic eruptions that cool the planet temporarily by reflecting sunlight away, the Tonga eruption had the opposite effect due to the large amount of water vapor it released. The study found that the eruption projected cooling sulfur dioxide aerosols into the stratosphere, but also expelled a significant amount of water vapor, leading to a warming effect on global temperatures.

The study also assessed the impact of the eruption on global temperature thresholds, specifically the 1.5C warming threshold set by the Paris Agreement. The research found that the eruption increased the likelihood of global temperatures exceeding the 1.5C threshold by seven percentage points, making it more likely to occur in the next five years.

While the temporary warming caused by the eruption may garner media attention, the study emphasizes that the Paris Agreement’s temperature limits are focused on long-term global warming attributable to human influence, not natural climate variability like volcanic eruptions. The researchers suggest that the impact of the Tonga eruption on global temperatures will be temporary and will fade over the next five to ten years.

Overall, the study highlights the complex interplay between natural events like volcanic eruptions and human-induced climate change, underscoring the need for further research to better understand and quantify these interactions.