Volcanic Activity Linked to Global Warming, Destruction of the Ozone Layer; may have doomed habitability on Mars and Venus | The Weather Channel – Articles from The Weather Channel
Extremely large volcanic eruptions called “flood basalt eruptions” could dramatically alter Earth’s temperature and demolish the ozone layer that protects life from the Sun’s ultraviolet rays, according to a new NASA climate simulation.
The research has been published in Geophysical Research Letters and contradicts previous studies indicating that these volcanoes cool the climate.
“We expected intense cooling in our simulations,” said Scott Guzewich of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “However, we found that a brief cooling period was overwhelmed by a warming effect,” they explained.
Although the loss of ozone was not a surprise, the simulations indicated the potential magnitude of the destruction, “a reduction of about two-thirds from global mean values, roughly equivalent to the whole of the planet having a thinning of the ozone layer comparable to a severe ozone hole in Antarctica,” Guzewich said.
Flood basalts are regions with a series of secular eruptive episodes and occur over time periods of hundreds of thousands of years, sometimes even longer.
Some of these eruption events occurred around the same time as mass extinction events, and many are associated with extremely hot periods in Earth’s history. They also appear to have been common on other terrestrial worlds in our solar system, such as Mars and Venus.
The research suggests that while extensive basalt eruptions on Mars and Venus may have helped warm their climates, they may have doomed the long-term habitability of those worlds by contributing to water loss.
The team used the Goddard Earth Observing System’s chemistry-climate model to simulate a four-year phase of the Columbia River Basalt (CRB) eruption that occurred between 15 and 17 years ago. million years ago in the Pacific Northwest of the United States.
The CRB eruptions were likely a mix of explosive events that sent material high into the upper troposphere and lower stratosphere (about 13 to 17 kilometers a.s.l.) and effusive eruptions that did not extend above 3 kilometers in altitude.
The simulation assumed that explosive events occurred four times a year and released about 80% of the sulfur dioxide gas from the eruption.
The team found that globally there was a net cooling for about two years before the warming overwhelmed the cooling effect.
“The warming persists for about 15 years (the last two years of the eruption, then another 13 years or so),” Guzewich said.
The predicted influx of water vapor into the stratosphere also helps explain the severity of ozone depletion.
“Ozone depletion happens in different ways,” says Guzewich. “After the eruption, the circulation of the stratosphere changes in a way that discourages the formation of ozone. Second, all that water in the stratosphere also helps destroy ozone with the hydroxyl (OH) radical.”
Flood basalts also release carbon dioxide, a greenhouse gas as well, but they don’t seem to release enough to cause the extreme warming associated with some eruptions. Excessive warming of stratospheric water vapor could also provide an explanation for this.
The new simulation is the most comprehensive ever for basalt eruptions and incorporates the effects of atmospheric chemistry and climate dynamics on each other, revealing an important feedback mechanism that previous simulations had missed.
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