Recent research from a team including Dr. Andrew Dessler, an atmospheric scientist at Texas A&M University, is challenging the widely held belief that the 2022 Hunga Tonga volcano eruption contributed to Earth’s recent extreme warmth. Contrary to initial assumptions, their findings indicate that the eruption actually had a cooling effect on the global climate.
The Hunga Tonga eruption, occurring over two days in mid-January 2022, was a significant event, releasing vast amounts of volcanic aerosols and water vapor into the atmosphere. Unlike past volcanic eruptions, such as Tambora in 1815 and Mt. Pinatubo in 1991, which led to global cooling by blocking sunlight with aerosols, Hunga Tonga’s underwater eruption added an unprecedented amount of water vapor to the stratosphere, increasing its total water content by about 10%.
Initial Speculation and New Findings
Given that water vapor is a potent greenhouse gas, there was initial speculation that this might explain the extreme global warmth observed in 2023 and 2024. However, the team’s research, published in the Journal of Geophysical Research: Atmospheres, reveals the opposite. Their analysis shows that the eruption resulted in more energy leaving the Earth’s climate system than entering it, thus inducing a slight cooling effect.
Dr. Dessler emphasized, “Our paper pours cold water on the explanation that the eruption caused the extreme warmth of 2023 and 2024. Instead, we need to focus primarily on greenhouse gases from human activities as the main cause of the warming, with a big assist from the ongoing El Nino.”
The research, titled “Evolution of the Climate Forcing During the Two Years after the Hunga Tonga-Hunga Ha’apai Eruption,” was a collaborative effort involving NASA and NOAA scientists. The team utilized satellite data to analyze aerosols and water vapor, among other variables, to estimate the Earth’s climate system’s energy balance. Their findings support the conclusion that the eruption contributed to cooling, similar to other major volcanic events.
Dr. Mark Schoeberl, the paper’s first author and chief scientist at the Science and Technology Corporation in Hamburg, Virginia, highlighted the importance of this research for future climate studies. “Our understanding of the Hunga Tonga eruption is largely thanks to the investment in stratospheric satellite measurements by NOAA and NASA over the past two decades.”
This research has significant implications for climate science and public understanding. By debunking the notion that the Hunga Tonga eruption was a major factor in recent warming, the study reinforces the role of human-induced greenhouse gas emissions as the primary driver of climate change. This is particularly crucial amid ongoing debates and misinformation about global warming causes.
Moreover, Schoeberl stressed the importance of continued investment in satellite-based stratospheric measurements to prevent a “stratospheric data desert,” as some critical instruments are not being replaced.
Future Research Directions
While the study provides crucial insights, it also raises new questions. Unresolved issues include the low levels of sulfur dioxide produced by the eruption and its minimal impact on the 2023 ozone hole over Antarctica. Additionally, the persistence of water vapor in the stratosphere beyond model predictions suggests more to learn about stratospheric circulation processes.
As scientists continue to investigate these phenomena, Dessler and Schoeberl’s work underscores the need for ongoing research and precise data to address the complex challenges of climate change.
Reference: https://www.preventionweb.net/news/new-study-disputes-hunga-tonga-volcanos-role-2023-24-global-warm