Dr Fommel said any estimates of how much additional warming the Tonga eruption would add was highly speculative at this point. “But I wouldn’t be surprised if they were the same size” as Pinatubo, he said, just the opposite. He added that the additional warming will likely last longer than the cooling after Pinatubo.
Susan Solomon, an MIT atmospheric scientist who described the temperature effects of changes in stratospheric water vapor in a 2010 study, said the Tonga eruption “could add something on the order of 0.05 degrees of warming to the global mean temperature “. at five years.
“It is lower than we would expect from carbon dioxide, which is closer to 0.1-0.2 degrees per decade,” he said. Dr. Solomon was not involved in the research on Tonga.
All of this water vapor will also likely change the chemistry of the atmosphere that destroys ozone, the oxygen molecule that protects life on Earth from the sun’s harmful ultraviolet rays.
‘By significantly increasing the amount of water vapor, this should reduce the amount of ozone,’ said Dr Fommel. But this would be temporary, he said, because the formation and destruction of ozone is a “continuing cycle”.
Dr Solomon said that any loss of ozone near the boundary of the stratosphere and lower atmosphere would also likely lead to some surface cooling, which would counteract the warming of the added water vapor.
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