The ominous hole in the ozone layer above the Antarctic is shrinking — but scientists warn not to celebrate just yet.
Once as large as the United States, the gap is now a quarter of the size it was just 12 months ago, a team of British experts found.
The ozone layer is important because it acts as a shield that protects us from the Sun’s harmful radiation.
It’s made up of oxygen atoms and scientists have been tracking a giant hole in it over the South Pole since the 1970s.
Researchers at the EU’s Copernicus Atmosphere Monitoring Service (CAMS) looked at how the ozone hole is progressing using an array of weather satellites.
It now covers an area spanning 1.9 million square miles, down from 7.7 million square miles in September 2018, reports the BBC.
That means the hole is the smallest it’s been in three decades, though scientists warn not to pop the champagne just yet.
Back in 2017, the hole covered 3.9 million square miles — around the size of the United States — so it’s pretty variable from year to year.
This variability means the shrinking of the hole doesn’t necessarily equate to a slowing down of climate change, said Richard Engelen, deputy head of CAMS.
“Right now I think we should view this as an interesting anomaly,” Richard told the BBC.
“We need to find out more about what caused it.”
Ozone is constantly being made and destroyed in the stratosphere, about 18 miles above the Earth’s surface.
Under normal conditions, the protective layer exists in perfect equilibrium.
However, pollution pumped into the air by human activities like the use of aerosol spray cans upsets this balance and causes the ozone to deplete.
The Montreal Protocol signed by governments in 1987 sought to repair some of the damage by banning some of humanity’s most harmful chemicals.
Thinning of the Ozone typically begins just after the Antarctic winter each year.
Losses started earlier than usual in 2019, but a sudden warming of the stratosphere slowed the process down.
Richard said the process is unlikely linked to climate change.
“It’s not really related to the Montreal Protocol where we’ve tried to reduce chlorine and bromine in the atmosphere because they’re still there,” he said.
“It’s much more related to a dynamical event. People will obviously ask questions related to climate change, but we simply can’t answer that at this point.”
A full recovery of the ozone to pre-1970 levels isn’t expected until around 2060.