A ‘once every 7.5 million years’ event is currently unfolding in Antarctica: ‘To say unprecedented isn’t strong enough’

Laurelle Stelle
Thu, August 10, 2023 



In the past eight years, sea ice in Antarctica has reached a new record low four times, the Australian Broadcasting Corporation (ABC) reports. The first three times, ice levels that have dropped in the summer have rebounded in the winter.

But this year — during what is currently winter in Antarctica — scientists have confirmed that the ice is not re-forming, leaving long stretches of the Antarctic coastline bare.
What’s happening?

According to physical oceanographer Edward Doddridge, this is the first time an event like this has been observed, the ABC reports — and it’s extremely unlikely to have happened on its own.

“To say unprecedented isn’t strong enough,” Doddridge told the ABC. “This is a five-sigma event. … Which means that if nothing had changed, we’d expect to see a winter like this about once every 7.5 million years. … There are people saying it could be natural variability … but it’s very unlikely.”

According to Doddridge and others, the most likely cause is human activity. People create air pollution through activities like burning fuel, and that pollution traps heat on our planet, heating up the atmosphere and the ocean. Some combination of warmer water and higher-energy weather patterns is likely what’s melting the ice, scientists told the ABC.
Why does the loss of Antarctic ice matter?

Polar ice is a major factor in the Earth’s “albedo,” which is the amount of light reflected from the surface instead of being absorbed. When there’s more ice, the planet’s albedo is higher, and the sun doesn’t warm it as quickly. When ice melts, the planet starts absorbing more heat.

This also creates “ice-albedo feedback,” the ABC says — a vicious cycle in which melting ice makes the ocean heat up faster, causing even more ice to melt. If too much of the polar ice is lost, it could reach a tipping point that will lead to the Earth heating up much more quickly.

Petra Heil, a sea ice physicist from the Australian Antarctic Division, told the ABC, “We might end up in a new state. That would be quite concerning to the sustainability of human conditions on Earth, I suspect.”

A much hotter environment has frightening implications for human health. It could also destroy the fish we rely on for food, the farmland where we grow crops, and the rainforests we need for oxygen.

What can be done about the vanishing ice?

The best hope for the planet is to stop the runaway air pollution causing our planet to heat up. However, it needs to happen quickly.

“I think a lot of people have the time line too long out, saying this won’t affect them,” Heil told the ABC. “I’m pretty convinced that this is something my generation will experience.”