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NASA warns that some volcanoes could warm the climate and destroy the ozone layer

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New[{” attribute=””>NASA climate simulation suggests that extremely large volcanic eruptions called “flood basalt eruptions” could significantly warm Earth’s climate and devastate the ozone layer that shields life from the Sun’s ultraviolet radiation.

The findings contradict prior research that found these volcanoes cool the climate. The simulation also suggests that while extensive flood-basalt eruptions on Mars and Venus may have helped warm their climates, they may have also doomed the long-term habitability of these worlds by contributing to water loss.


NASA’s new climate modeling shows that extremely large volcanic eruptions, called “flood basaltic eruptions”, can significantly warm the Earth’s climate and destroy the ozone layer, which protects life from solar UV radiation. Credit: NASA / GSFC / James Traley

Unlike short, explosive volcanic eruptions such as Pinatube or January Hunga Tonga-Hunga Haapai occurring over hours or days, flood basalts are regions with a series of episode eruptions that last, perhaps, centuries each, and that occur over hundreds of thousands of years, sometimes even longer. Some of them occurred at about the same time as the events of the mass extinction, and many of them are associated with extremely warm periods in the history of the Earth. They also seem to have been common in other terrestrial worlds of our solar system, such as Mars and Venus.

“We’ve been expecting intense cooling in our simulations,” said Scott Guzevich of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “However, we found that the short cooling period was overwhelmed by the warming effect.” Guzevich is the lead author of an article on this study published February 1, 2022 in the Journal Letters of geophysical research.

Flood-basalt deposit on Mars

Image of the flooding of basalt on Mars in the Marte Wallis area, made by the High Resolution Science Imaging Experiment (HiRISE) aboard the NASA Mars Reconnaissance Orbiter spacecraft. Author: NASA / University of Arizona / HiRISE

Although ozone loss did not come as a surprise, the simulation showed a potential magnitude of destruction, “a decrease of about two-thirds compared to world averages, roughly equivalent to the depletion of global ozone comparable to a serious ozone hole” in Anta. . Guzevich.

The researchers used Goddard Earth Observation System is a chemical-climatic model to simulate a four-year phase Colombia River Basalt Eruption (CRB). which occurred 15 to 17 million years ago in the Northwest Pacific of the United States. The model calculated the impact of the eruption on the troposphere, the turbulent lower atmosphere with most of the water vapor and weather, and the stratosphere, the next layer of the atmosphere that is mostly dry and calm. The CRB eruptions were probably a mixture of explosive events that sent material high into the upper troposphere and lower stratosphere (approximately 8 to 10.5 miles or 13 to 17 kilometers altitude) and effusive eruptions that did not extend above 1.9 miles (about 3 kilometers) in height. The simulation estimated that the blasts occurred four times a year and emitted about 80% of the sulfur dioxide gas as a result of the eruption. They found that on a global scale there was pure cooling for about two years before warming overcame the cooling effect. “Warming has been going on for about 15 years (the last two years of the eruption, and then another 13 years),” Guzevich said.

“We were expecting intense cooling in our simulations. However, we found that the short cooling period was overwhelmed by the warming effect. ” – Scott Guzevich

The new simulation is the most complete that has been done for flood basaltic eruptions, and combines the effects of atmospheric chemistry and climate dynamics on each other, revealing an important feedback mechanism that was not present in previous simulations.

“Such eruptions, which we simulated, emit huge amounts of sulfur dioxide gas,” said Guzevich. “Chemistry in the atmosphere quickly converts these gas molecules into solid sulfate aerosols. These aerosols reflect visible sunlight, which causes the initial cooling effect, but also absorb infrared radiation, which heats the atmosphere in the upper troposphere and lower stratosphere. Warming of this area of ​​the atmosphere allows water vapor (which is usually near the surface) to mix in the stratosphere (which is usually very dry). We see an increase in water vapor in the stratosphere by 10,000%. Water vapor is very effective greenhouse gasand emits infrared radiation that heats the surface of the planet ”.

The predicted surge of water vapor into the stratosphere also helps explain the severity of ozone depletion. “Ozone depletion occurs in several different ways,” Guzevich said. “After the eruption, the circulation of the stratosphere changes in a way that prevents the formation of ozone. Second, all the water in the stratosphere also helps destroy ozone by the hydroxyl radical (OH).

Flood basalts also emit carbon dioxide, greenhouse gas, but they don’t seem to emit enough to cause the extreme warming associated with some eruptions. The explanation may give an excess of stratospheric water vapor heating.

Although in the distant past Mars and Venus could have oceans of water, now both are very dry. Scientists are investigating how these worlds lost most of their water to become inhospitable to life. If the surge of water vapor in the upper atmosphere of the atmosphere predicted by the simulation, realistic, extensive flood volcanism could contribute to their arid fate. When water vapor rises high in the atmosphere, it becomes prone to rupture by sunlight, and light hydrogen atoms from water molecules can escape into space (water is two hydrogen atoms associated with oxygen[{” attribute=””>atom). If sustained over long periods, this could deplete oceans.

Reference: “Volcanic Climate Warming Through Radiative and Dynamical Feedbacks of SO2 Emissions” by Scott D. Guzewich, Luke D. Oman, Jacob A. Richardson, Patrick L. Whelley, Sandra T. Bastelberger, Kelsey E. Young, Jacob E. Bleacher, Thomas J. Fauchez and Ravi K. Kopparapu, 1 February 2022, Geophysical Research Letters.
DOI: 10.1029/2021GL096612

The research was funded by the NASA Goddard Sellers Exoplanet Environments Collaboration and NASA’s Center for Research and Exploration in Space Science and Technology, NASA Cooperative Agreement Award #80GSFC17M0002.

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