Scientists have looked back in time to reconstruct the past life of Antarctica’s “Doomsday Glacier” — nicknamed because its collapse could cause catastrophic sea level rise. They have discovered it started retreating rapidly in the 1940s, according to a new study that provides an alarming insight into future melting.
The Thwaites Glacier in West Antarctica is the world’s widest and roughly the size of Florida. Scientists knew it had been losing ice at an accelerating rate since the 1970s, but because satellite data only goes back a few decades, they didn’t know exactly when significant melting began.
Now there is an answer to this question, according to a study published Monday in the journal Proceedings of the National Academy of Sciences.
By analyzing marine sediment cores extracted from beneath the ocean floor, researchers found the glacier began to significantly retreat in the 1940s, likely kicked off by a very strong El Nino event — a natural climate fluctuation which tends to have a warming impact.
Since then, the glacier has been unable to recover, which may reflect the increasing impact of human-caused global warming, according to the report.
What happens to Thwaites will have global reverberations. The glacier already contributes four per cent of sea level rise as it sheds billions of tons of ice a year into the ocean. Its complete collapse could raise sea levels by more than two feet.
But it also plays a vital role in the stability of the West Antarctic Ice Sheet, acting like a cork holding back the vast stretch of ice behind it. Thwaites’ collapse would undermine the stability of the ice sheet, which holds enough water to raise sea levels by at least 10 feet, causing catastrophic global flooding.
The study’s findings match previous research on the neighbouring Pine Island Glacier, one of the largest ice streams in Antarctica, which scientists also found started retreating rapidly in the 1940s.
This makes the research significant, said Julia Wellner, an associate professor of geology at the University of Houston and one of the study’s authors. What’s happening to Thwaites is not specific to one glacier, but part of the bigger context of a changing climate, she told CNN.
“If both glaciers are retreating at the same time, that’s further evidence that they’re actually being forced by something,” Wellner said.
To build a picture of Thwaites’ life over the past nearly 12,000 years, the scientists took an icebreaker vessel up close to the edge of the glacier to collect ocean sediment cores from a range of depths.
These cores provide a historical timeline. Each layer yields information about the ocean and ice going back thousands of years. By scanning and dating the sediments, the scientists were able to pinpoint when the substantial melting began.
From this information, they believe Thwaites’ retreat was set off by an extreme El Nino that happened at a time when the glacier was likely already in a phase of melting, knocking it off balance. “It’s sort of like if you get kicked when you’re already sick, it’s going to have a much bigger impact,” Wellner said.
The findings are alarming because they suggest that once big changes are triggered, it’s very hard to stop them, said James Smith, a marine geologist at the British Antarctic Survey and a study co-author.
“Once an ice sheet retreat is set in motion it can continue for decades, even if what started it gets no worse,” he told CNN.
While similar retreats have happened much further back in the past, the ice sheet recovered and regrew, Smith said. But these glaciers “show no signs of recovery, which likely reflects the growing influence of human-caused climate change.”
Ted Scambos, a glaciologist at the University of Colorado Boulder who was not involved in the research, said the study confirms and adds detail to our understanding of how Thwaites’ retreat began.
A system that was already close to being unstable “took a big shot from a mostly natural event,” said Scambos, referring to the El Nino. “Further events arising more from the warming climate trend took things further, and started the widespread retreat we’re seeing today,” he told CNN.
Martin Truffer, a physics professor at the University of Alaska Fairbanks, said the research shows if a glacier is in a sensitive state, “a single event can knock it into a retreat from which it is difficult to recover.”
“Humans are changing the climate and this study shows that small continuous changes in climate can lead to step changes in glacier state,” said Truffer, who was not involved in the research.
Antarctica is sometimes called the “sleeping giant,” because scientists are still trying to understand how vulnerable this icy, isolated continent may be as humans heat up the atmosphere and oceans.
Wellner is a geologist — she focuses on the past not the future — but she said this study gives important and alarming context for what might happen to the ice in this vital stretch of Antarctica.
It shows that even if a trigger for rapid melting has ended, that doesn’t mean the response stops. “So if the ice is already in retreat today,” she said, “just because we might stop warming, it might not stop its retreat.”
NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.
Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.
She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.
Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.
“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.
It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.
Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.
Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.
“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.
He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.
Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
