Australia’s ‘Black Summer’ fires devastated the ozone layer: study

Australia’s catastrophic “Black Summer” bushfires have significantly affected the hole in the earth’s ozone layer, according to a new report released on Friday.

The report, published in Nature journal Scientific Reports, links the unprecedented smoke being released from the fires to the ozone hole over Antarctica.

The fires, which burned 5.8 million hectares in eastern Australia in late 2019 and early 2020, were so intense that dozens of smoke-drenched pyrocumulonimbus clouds formed.

Dubbed the “fire-breathing cloud dragon” by NASA, pyrocumulonimbus clouds are so powerful that they can affect local weather and cause fire tornadoes and thunderstorms.

During the “Black Summer,” these clouds shot up more smoke into the atmosphere than the previous record set by the 2017 North American wildfires.

Around New Year’s Day 2019, uncontrolled fires along the east coast of Australia caused a pyrocumulonimbus event that lasted for days.

The result, according to researchers from the University of Exeter and the University of Manchester, was that “millions of tons of smoke and associated gases were injected into the upper troposphere and lower stratosphere”.

A buildup of smoke particles, in turn, caused the lower stratosphere to warm to levels not seen since Mount Pinatubo erupted in 1991, they found.

Because of this stratospheric warming, the fires also lengthened the Antarctic ozone hole, which appears over Antarctica every spring and “reached record observations in 2020.”

The hole was first created by human pollution — specifically the chlorofluorocarbons (CFCs) that were once emitted by many refrigerators — but in recent decades global collaboration has given the ozone layer a chance to repair itself.

The Montreal Protocol, signed in 1987 and since ratified by 195 countries, greatly reduced the amount of CFCs in the atmosphere and the ozone layer should fully recover by 2060, according to the United Nations model.

However, the researchers warn that similar events – in which pyrocumulonimbus clouds shoot smoke high into the stratosphere – will become more likely as climate change increases the frequency and intensity of bushfires.

Professor James Haywood told AFP that climate change could “absolutely” wipe out the gains made by the Montreal Protocol.

“Our climate models indicate an increase in the frequency and intensity of wildfires in the future under global warming. This could lead to more events like this in 2020, which in turn could lead to more ozone depletion,” he said.

“So the significant efforts we’ve made to protect the ozone hole could be thwarted by global warming.”