“We can’t do much”: scientists drilled into the ice of Antarctica and were horrified

According to a study published Wednesday in the journal Nature Geoscience, parts of Antarctica’s ice sheet thinned by 450 meters—a height greater than the Empire State Building—in just 200 years at the end of the last ice age, CNN reported.

According to the study authors, this is the first direct evidence of such rapid ice loss anywhere in Antarctica.

While scientists knew that there was more ice cover at the end of the last ice age than it is today, much less was known about exactly when this reduction occurred, explains Eric Wolf, a glaciologist at the University of Cambridge in the UK and an author of the study.

This study changes that, the glaciologist told CNN: “We were able to tell exactly when it retreated, but we were also able to tell how quickly it retreated.”

It’s now clear that the ice sheet has retreated and thinned very quickly in the past, says Eric Wolf, but the danger is that it could start again. “If he does start to retreat, he will do so very quickly indeed,” he added.

This could have catastrophic consequences for global sea level rise. The West Antarctic ice sheet contains enough water to raise sea levels by about 5 meters – more than 16 feet – which would cause devastating floods in coastal cities around the world.

The study is “great detective work” about much of the Antarctic ice sheet, said Ted Scambos, a glaciologist at the University of Colorado Boulder.

The key message is that “the amount of ice stored in Antarctica can change very quickly – at a pace that would be difficult for many coastal cities to cope with,” he told CNN.

Ice cores are historical archives of the Earth’s atmosphere, CNN explains. Composed of layers of ice that were formed by snowfall and compacted over thousands of years, they contain bubbles of ancient air as well as pollutants that provide a record of environmental changes over millennia.

The ice core analyzed in the study was drilled from the Skytrain Ice Rise, located at the edge of the ice sheet, near the point where the ice begins to float and becomes part of the Ronne Ice Shelf.

Scientists recovered it in 2019 through a painstaking process that involved constant drilling over 40 days, lifting the thin cylinder of ice several feet at a time. They then cut the core into sections, packed them into insulated boxes kept at minus 20 degrees Celsius, and shipped them to the UK by plane and then by ship.

Once in the UK, the scientists measured water isotopes in the ice core, which provide information about past temperatures. Warmer temperatures indicate lower ice levels—think of it like a mountain, Wolf said, the higher you go, the colder it gets.

The researchers also measured the pressure of trapped air bubbles in the ice. The underlying, thinner ice contains higher pressure air bubbles.

It was a surprise when the data showed how quickly the ice thinned at the end of the last ice age, notes Eric Wolf. “We actually spent a lot of time checking to make sure we didn’t make any mistakes in the analysis.”

The West Antarctic ice sheet is particularly vulnerable to climate change because the land underneath is below sea level and slopes downwards. When warm water gets underneath it, it can melt very quickly. “This could be a runaway process, and this is obviously what happened 8,000 years ago,” Wolff emphasizes.

What makes the findings so alarming, said Isabel Rowell, an ice core specialist with the British Antarctic Survey and co-author of the study, is that once it happens, “there’s really very little we can do to stop it,” she said. CNN.

According to Wolf, it is important “not to go too far,” and that means combating climate change. “We can still avoid these tipping points,” he said.

The new data will help improve the accuracy of the models scientists use to predict how the ice sheet will respond to future global warming, the report says.

David Thornalley, an ocean and climate scientist at University College London, said the findings were “astonishing.” He cautioned that because the study looked at a period 8,000 years ago when climate conditions were different, the results are not a direct example of what might happen today. But, he added, they are still able to provide “insight into how ice sheets might break down.”

The study comes as scientists continue to sound the alarm about what is happening to Earth’s most isolated continent.

For example, the Thwaites Glacier, also located in West Antarctica, is melting rapidly. A 2022 study says the Thwaites Glacier, dubbed the Doomsday Glacier because of the catastrophic impact its collapse would have on sea level rise, is hanging on by a thread as the planet warms.

This new study reinforces those concerns, Scambos says. “This shows that the same processes we are seeing now beginning in areas like Thwaites Glacier were previously occurring in similar areas of Antarctica, and indeed the rate of ice loss was consistent with our worst fears of rampant ice loss.”