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Australia Never Had An Ozone Hole -- But Antarctica's Is Healing

You thought we had one, didn't you?

01/07/2016 11:18 AM AEST | Updated 15/07/2016 12:56 PM AEST
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Per-Gunnar Ostby
Join this juvenile emperor penguin in taking a moment to pat ourselves on the back.

Remember hearing about that crazy hole in the ozone layer above Australia? You know, the one that means we need to wear more sunscreen or else we'll get burned more easily. The one that we outlawed the use of CFCs in spray cans to protect.

We hate to break it to you, but.... there is no hole in the ozone layer above Australia. Never has been.

What has been observed is a massive hole over Antarctica, which scientists have been observing for many years.

Back in 1987 when the world pulled together for the Montreal Protocol to phase out damaging CFCs, we were warned the hole in Antarctica could extend to Australia, but it never did.

via GIPHY

And today's good news? Human action in the face of an ozone threat has led to the gradual repair of the hole over Antarctica. The hole is healing.

Melbourne Energy Institute deputy director Roger Dargaville said a lot of people had it wrong.

"There is a common misconception that the ozone hole extends over Australia, and that ozone depletion is the reason why we need to be particularly vigilant with sunscreen in the Australian summer," Dargaville said.

"Skin cancer is of serious concern because of the natural high concentrations of UV received in our part of the world.

"But, had the Montreal Protocol not been signed in 1987, beginning the process to phase out CFCs, the ozone hole could well have expanded over Australia which would have had disastrous consequences for humans, animals and plants."

Ho New / Reuters
A NASA visualisation of the hole in the ozone layer in 2000. Note the absence of Australia, like, anywhere nearby.

Australia's ozone was slightly depleted in the 1980s and 1990s (The Bureau of Meteorology estimated a temporary five percent decrease) but the Antarctic hole only occasionally affected us.

As the Bureau of Meteorology's fact sheet says:

The ozone hole has only ever been observed to be well south of the Australian mainland and Tasmania. In fact, during springtime, when the hole is in existence, ozone levels over southern Australian cities are at their highest.

However, after the ozone hole has broken up parcels of ozone depleted air mixed with mid latitude air move northwards. These parcels can move over the southern part of Australia and cause a reduction in total ozone values.

Back to the actual ozone hole in Antarctica. Three decades after the historic Montreal Protocol, where the world agreed to stop using CFCs, researchers from the U.S. and U.K. found the hole's healing was finally observable.

University of Melbourne honorary professorial fellow Ian D. Rae said it was a great start, even if it did take several decades.

"Are we there yet? Well, not quite but this is a good news story that's been coming for some time.

"Regular monitoring first showed a decrease in the rate of growth of the ozone hole and then a 'plateau' that suggested that the being actions taken under the protocol on substances that deplete the ozone layer were doing the job.

What's The Ozone Layer And How Do CFCs Affect It?

Ozone is a type of oxygen gas that blankets the planet, mostly about 15-20km from Earth's surface.

It's naturally occurring and is thicker and thinner over different parts of the globe.

Ozone absorbs ultraviolet radiant energy from the sun, saving the Earth's plants and animals from trauma, including an increase in skin cancers for people and a hotter climate.

A thicker ozone layer means less ultraviolet energy reaches Earth.

In the 1970's, researchers first discovered man-made chemicals called chloroflourocarbons (CFCs) could damage ozone, and by the 1980's the hole in Antarctica's ozone was discovered.

CFCs were once used in industries like refrigeration, air-conditioning and in commercial spray-on aerosols but the Montreal Protocol, signed in 1987, phased out their use.

"Complete recovery will take a long time, perhaps half a century," Rae said.

"Many of the ozone-depleting substances that we put into the atmosphere are still there and will be there for decades until natural processes destroy them."

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