Discoveries

March 14, 2023

Delaying Recovery

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The bushfires in Australia over the summer of 2019-2020 were catastrophic for the continent’s environment and wildlife, harming around three billion animals.

Now, a new study is suggesting that smoke from the deadly blazes is depleting the Earth’s ozone layer, the Guardian reported.

The planet’s protective layer – part of the stratosphere – is made up of ozone gas that absorbs high-energy ultraviolet rays from the Sun. This decreases the amount of radiation that reaches the Earth’s surface.

A research team studied smoke aerosols released from the fires, which had reached the stratosphere via pyrocumulonimbus cloud – a “fire storm cloud” that forms when a blaze is big and intense.

The team found that smoke particles can activate chlorine to form compounds that then degrade ozone molecules. More specifically, they determined that the ozone-destruction process occurred through hydrochloric acid in the stratosphere dissolving in the smoke aerosols.

Their findings show that the wildfires temporarily degraded the protective layer by three to five percent in 2020.

Lead author Susan Solomon and other researchers explained that these findings could put into jeopardy the recovery of the ozone layer: A United Nations panel of scientists estimated earlier this year that the ozone layer is on track to recover within four decades, Axios added.

But Solomon warns that this recovery could be delayed because of increased levels of wildfire smoke in the atmosphere. Climate scientists predict that wildfires will become more frequent and intense over the coming decades because of global warming and land-use change.

“The question in my mind is: Is the man-made chlorine going to get … diluted and destroyed out of the atmosphere faster than global climate change is going to increase the frequency and intensity of this kind of fire?” Solomon noted. “I think it’s going to be a race.”

This story originally appeared in the March 14, 2023 newsletter, Coming Due.