2019 and 2020 Australian bushfires have depleted the ozone layer

The devastating bushfires that hit Australia in 2019 and 2020 had a significant impact on the hole in the ozone layer, according to work published on Friday.

The study, published in the journal “Scientific Reports” affiliated with the Nature group, establishes a link between the fires in the ozone layer above Antarctica and the unprecedented smoke emitted by the hole.

According to researchers from the Universities of Exeter and Manchester (United Kingdom), “millions of tons of smoke and gas (…) were injected into the upper troposphere and lower stratosphere”.

According to their work, smoke particles accumulated as the lower stratosphere warmed from the 1991 eruption of Pinatubo in the Philippines.

Because of this warming, fires have widened the holes in the ozone layer that appear every spring in Antarctica and “reached record levels in 2020”.

The fires, which burned 5.8 million hectares in eastern Australia from late 2019 to early 2020, were so intense they produced dozens of pyrocumulonimbus clouds, clouds formed by smoke rings.

Pyrocumulonimbus clouds, which the US space agency NASA calls “fire-breathing cloud dragons”, are so powerful that they influence local weather conditions, causing fire tornadoes and thunderstorms.

The hole in the ozone layer was created by anthropogenic pollution, particularly chlorofluorocarbons (CFCs) emitted by many refrigerators.

However, over the past few decades, global cooperation has provided an opportunity to restore the ozone layer.

The Montreal Protocol (Canada), signed in 1987 and ratified by 195 countries, has drastically reduced the amount of CFCs in the atmosphere, and the ozone layer can be fully recovered by 2060, according to UN estimates.

However, researchers warn that increasing climate change will increase the frequency and intensity of wildfires, making similar events — where pyrocumulonimbus clouds shoot smoke into the stratosphere — more likely.

“Our massive efforts to protect the hole in the ozone layer could be overturned by global warming,” Professor James Haywood told AFP.