Largest Arctic ozone hole ever recorded opens up over the North Pole

A new hole has opened up in the ozone layer — but it's not where scientists would expect to find it. The huge hole has been spotted in the Arctic, on the other side of the planet from the infamous hole that forms each year above Antarctica.

Scientists from the European Space Agency said this week that this rare hole is the largest of its kind ever recorded over the planet's northern hemisphere. It covers an area about three times the size of Greenland, according to the journal Nature. 

"From my point of view, this is the first time you can speak about a real ozone hole in the Arctic," Martin Dameris, an atmospheric scientist at the German Aerospace Center in Oberpfaffenhofen told Nature.

Earth's atmospheric ozone layer acts as a protective barrier between the sun's harmful rays and the Earth's surface. Human-made chemicals called chlorofluorocarbons have been destroying the layer for the past century, causing thinning, and eventually, the massive hole that formed in Antarctica in the 1980s. 

Experts point to "unusual atmospheric conditions" as the cause of the massive hole, including freezing temperatures that bring high-altitude clouds together. Industrial chemicals interact with these clouds to eat away at the ozone layer. 

While temperatures consistently plummet in the South Pole each year, these conditions are rare in the North, making ozone depletion much less common. 

According to Markus Rex, an atmospheric scientist at the Alfred Wegener Institute in Potsdam, Germany, powerful winds created a polar vortex this year, causing more cold air above the Arctic than in any winter recorded since 1979. Lower temperatures mean high-altitude clouds — and the destruction of the ozone. 

After signing the Montreal Protocol in 1987, 197 countries agreed to phase out chemicals like chlorofluorocarbons in order to protect the ozone from further damage, which has contributed to a decrease in the size of the hole over Antarctica. 

While the newest hole is concerning, scientists say it is expected to heal within the next month as temperatures get warmer. The hole is still nowhere near as worrisome as its southern counterpart and doesn't currently threaten human health. 

If it were to drift to lower latitudes in the coming months, Rex said people would just need to be a bit more careful and apply sunscreen to avoid burns. "It wouldn't be difficult to deal with," he said. 

"Right now, we're just eagerly watching what happens," says Ross Salawitch, an atmospheric scientist at the University of Maryland in College Park. "The game is not totally over."

In 2018, NASA announced the first direct connection between the ban on chemicals and ozone-hole recovery in the Southern Hemisphere. However, it will still take decades for the layer to repair and the chemicals to completely vanish from the atmosphere.