Parts of Antarctica are doomed to collapse

It will take hundreds of years to fully melt and gradually raise sea levels by nearly 6 feet, but it will be enough to change how and where people live in the future, the study’s lead author said.

Researchers used computer simulations to calculate the future melting of a protective ice shelf that juts into the Amundsen Sea in West Antarctica. The study, published in the journal Nature Climate Change, suggests that even if future warming is limited to just a few tenths of a second, something many scientists say is unlikely to be achieved. (an international goal), we found that our ability to prevent it would be limited. Ocean warming could lead to the collapse of the West Antarctic ice sheet. ”

“Our main question here was: How much can we control ice shelf melting? How much melting can we prevent by reducing emissions?” of the study. Lead author Caitlin Norton, an oceanographer at the British Antarctic Survey, said: “Unfortunately, it’s not great news. Our simulations suggest that we are dealing with a rapid increase in ocean warming and ice shelf melting rates for the rest of the century.”

While past studies have described how dire the situation is, Norton is the first to use computer simulations to study the key dissolved components of the hot water that melts ice from below, and his research shows how the world Four scenarios were considered for how much carbon dioxide would be pumped. atmosphere. In both cases, the study found, ocean warming was too much for this part of the ice sheet to survive.

Norton watched as the Gatekeeper Ice Shelf, which floats above the sea in this part of Antarctica that is already below sea level, melted. When these ice shelves melt, there’s nothing to stop the glaciers behind them from flowing into the ocean.

Norton specifically investigated what would happen if future warming were somehow limited to an international goal of 1.5 degrees Celsius (2.7 degrees Fahrenheit) above mid-19th century levels, and would likely have a runaway melting process anyway. discovered. Global temperatures have already risen by about 1.2 degrees Celsius (nearly 2.2 degrees Fahrenheit) since before the Industrial Revolution, and at one point exceeded 1.5 degrees Celsius for much of this summer.

Norton’s research focused on the part of the West Antarctic ice sheet near the Amundsen Sea that is most at risk of melting from below. These include the massive Thwaites Ice Shelf, which is melting so rapidly that it has earned the nickname “Doomsday Glacier.” Although West Antarctica is only one-tenth the size of the continent’s southern part, it is more unstable than its wider eastern side.

That part of Antarctica is “doomed,” said Eric Rignot, an ice scientist at the University of California, Irvine, who was not involved in the study. “The damage has already been done.”

The ice sheet “will eventually collapse,” said Ted Scambos, an ice scientist at the University of Colorado who was also not involved in the study. That’s not a happy conclusion and I’m just saying it reluctantly. ”

Naughten is reluctant to use the word “doomed.” Because 100 years from now, the world may not only stop atmospheric carbon levels and global warming, but reverse it. But she said what is currently happening on the ground is a slow collapse that cannot be stopped, at least not until this century.

“I think it’s inevitable that we’re going to lose some of this area. It’s inevitable that the problem is going to get worse,” Naughten told The Associated Press. “Sea level rise happens over a very long period of time, so it’s inevitable that we’ll lose everything. In this study, he only looked up to 2100, so we’ll probably still have some control after 2100.”

Regardless of the words used, Norton said she and other scientists who have studied the region in previous studies believe that this part of Antarctica is “unsalvageable, or largely unsalvageable.” He concluded that.

Norton’s study does not calculate how much ice will be lost or how much sea level will rise and how fast. But if it all melted, she estimated that the amount of ice in the most at-risk areas would raise sea levels by about 5.9 feet.

But it will be a slow process and will continue for hundreds of years into the 2300s, 2400s and 2500s, she said.

Norton says it may seem like a long way off, but if the Victorians of the 1800s did something to dramatically change the shape of our world, we He said he wouldn’t look at them in a good light.

If this kind of sea level rise occurred over 200 years, it would be “absolutely catastrophic,” but if it could last for 2,000 years, humans would be able to adapt, Norton said.

“Coastal communities are going to either build around them or be abandoned,” Norton said.

Although this part of the Antarctic ice sheet is destined to be lost, there is still reason to reduce carbon pollution, as other vulnerable parts of the global environment can still be saved by reducing heat-trapping emissions. Naughten said.

Twila Moon, deputy principal investigator at the National Snow and Ice Data Center, who was not involved in the study, said she was concerned that most people would see nothing but pessimism in the study. .

“I don’t see much hope,” Norton said. “But that’s what science has taught me. That’s why I have to tell the world.”

Quoting former NASA scientist Kate Marvell, Norton said, “When it comes to climate change, we need courage, not hope. Courage is the determination to do well, even with no guarantee of a happy ending.” Thing.”