Forest fires harmful to the ozone layer – MO*

Smoke from forest fires is harmful to the ozone layer, according to a study published in the scientific journal Nature. The 2020 massive bushfires in Australia increased the gap over Antarctica by 10%.

In large wildfires, smoke is pumped high into the stratosphere to linger for more than a year, research shows. Scientists from the Massachusetts Institute of Technology (MIT) have now shown how smoke can cause a chemical reaction that damages the ozone layer.

The study focuses specifically on the black summerfires in Australia, in December 2019 and January 2020. Tens of millions of hectares of forest went up in smoke, and more than a million tonnes of particles were pumped into the atmosphere.

Ozone layer

MIT researchers have discovered a previously unknown chemical reaction between the particles and hydrochloric acid, a substance resulting from the breakdown of CFCs (publisher: cchlorofluorocarbons). Hydrochloric acid is harmless to ozone, but reaction with the particles can produce chlorine monoxide, which breaks down ozone.

The forest fires thus widened the hole in the ozone layer above Antarctica by 2.5 million square kilometres.

MIT has calculated that the Australian fires are likely to have depleted 3-5% of the ozone layer in regions over Australia, New Zealand and parts of Africa and South America.

The fires also have an effect on the polar regions. Forest fires have gouged the hole in the ozone layer above Antarctica by 2.5 million square kilometres, or about 10%.

Long term

It’s unclear what long-term effect wildfires will have on ozone recovery, the team said. The United Nations recently reported that the ozone layer is slowly recovering, thanks to international efforts to eliminate harmful chemicals.

But the MIT study shows that, as long as CFCs continue to circulate in the atmosphere, large fires can trigger a reaction that at least temporarily affects the ozone layer.