Study - Particles From Extreme Australian Bushfires Temporarily Depleted Earth's Ozone Layer By 3-5%
Particles in bushfire smoke can activate molecules that destroy the ozone layer, according to new research that suggests future ozone recovery may be delayed by increasingly intense and frequent fires. A study published in the journal Nature has found that smoke from the 2019-20 Australian bushfires temporarily depleted the ozone layer by 3% to 5% in 2020.
Smoke from the fires, which circulated around the globe, was ejected into the stratosphere, the second layer in Earth’s atmosphere, by a pyrocumulonimbus cloud.
In the ozone layer – part of the stratosphere – molecules of ozone gas absorb high-energy ultraviolet rays from the sun. This lessens the amount of radiation that reaches the Earth’s surface.
The lead researcher, Prof Susan Solomon, an atmospheric scientist at the Massachusetts Institute of Technology in the US, said the ozone destruction by smoke particles was similar to the process of the Antarctic ozone hole forming each spring, “but at much warmer temperatures”. Smoke aerosols, the researchers found, can activate chlorine to form compounds that then destroy ozone molecules.
Solomon said chlorine in the stratosphere had been decreasing since the 1987 Montreal protocol phased out the use of ozone-depleting chlorofluorocarbons. “There’s a tremendous science policy success story there,” she said. “The slow recovery of the ozone layer is on the order of 1% per decade in the mid-latitudes.” But she warned that more frequent fires could delay ozone recovery. “All of a sudden, in one year [2020], we had a 3% to 5% loss. It’ll recover if that’s the only year that it happens, but not if it keeps happening.
EDIT
https://www.theguardian.com/environment/2023/mar/08/smoke-from-australian-bushfires-depleted-ozone-layer-by-up-to-5-in-2020-study-finds
