Wildfires

Australian Wildfires Shredded the Ozone Layer

Massive wildfires that raged across southeast Australia in 2019–20 unleashed chemicals that chewed through the ozone layer, expanding and prolonging the ozone hole. A study, published today in Nature, describes how smoke combined with chlorine-containing molecules in the stratosphere — remnants of chemicals that are now banned — to cause the destruction of the ozone layer.

The Australian fires produced the largest smoke plume on record, releasing roughly one million tonnes of smoke to heights of up to 30 kilometres. That’s well into the stratosphere, the portion of the atmosphere that contains the ozone layer, which protects Earth from harmful ultraviolet rays. In the months after the wildfires, the hole in the ozone layer, which appears annually over Antarctica, was larger and lasted longer than in previous years.