A massive Atlantic Ocean current system, which affects climate, sea levels and weather systems around the world, may be about to be fatally disrupted.
A new report in the journal Nature Climate Change describes how a series of Atlantic Ocean currents have reached “an almost complete loss of stability over the last century” as the planet continues to warm. The report, authored by Dr. Niklas Boers, specifically analyzes data on ocean temperature and salinity to demonstrate that their circulation has weakened over the past few decades. If current trends continue unabated, they may slow to a dangerous level or even shut down entirely.
The series of currents in question is known as the Atlantic Meridional Overturning Circulation, or AMOC for short. The current system is sometimes likened to a series of conveyer belts: one “belt” flows north with warm water that, upon reaching the northern Atlantic, cools and evaporates, in the process increasing the salinity of water in that region. The saltier water becomes colder and heavier, sinking and flowing south to create a second “belt.” Those two currents are in turn connected by other oceanic features in the Southern Ocean, the Labrador Sea and the Nordic Sea.
The study reinforces earlier scientific studies which found the Atlantic Meridional Overturning Circulation system to be at its weakest in 1,600 years.
This so-called conveyer belt system has been in place for thousands of years or more, and ocean life is adapted to its rhythms. Indeed, AMOC, which scientists believe can slow down or turn off abruptly when temperatures increase, is also vital to maintaining humanity’s way of life. If it shuts down, temperature will plummet in Europe while the number of storms increases; changing weather conditions will lead to food shortages in South America, India and Western Africa; and rising sea levels along the North American eastern seaboard will force millions to flee their homes. Considering that AMOC is already starting to decline, this is a serious threat that could radically alter our planet in a matter of mere decades.
“This decline may be associated with an almost complete loss of stability over the course of the last century, and the AMOC could be close to a critical transition to its weak circulation mode,” the analysis explains.
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This is not the first troubling news which has emerged about AMOC. In February another study disclosed that AMOC could be weakened by 34% to 45% by the end of the century as Arctic ice and the Greenland Ice Sheet continue to melt. The new report, however, increases the growing sense of scientific alarm about AMOC’s integrity.
“This work provides provides additional support for our earlier work in the same journal Nature Climate Change suggesting that a climate change-induced slowdown of the ocean ‘conveyer belt’ circulation already underway, decades ahead of schedule, yet another reminder that uncertainty is not our friend,” Dr. Michael E. Mann, a distinguished professor of atmospheric science at Penn State University, wrote to Salon. “There are surprises in store, and they are likely to be unpleasant ones, when it comes to the climate crisis.”
Cristian Proistosescu, an assistant professor at the University of Illinois–Urbana-Champaign who studies climate dynamics and global warming consequences, was more measured in his assessment.
“If the worst-case scenario comes to pass — and that’s a big if — we can certainly expect to see dramatic changes in climate in the far north of Europe,” Proistosescu told Salon by email. He described a world in which Scandinavian winters are no longer mild, where precipitation patterns shift as far south as central Africa and in which other meteorological patterns alter radically. The worst case scenarios may be “somewhat unlikely,” he added, noting that the majority of updated climate models predict a gradual deterioration over the 21st century rather than an abrupt showdown.
“The data we have is too short to say with any real confidence whether the collapse of the North Atlantic Overturning Circulation is truly imminent,” Proistosescu concluded. “The question for me is how risk-averse should we be in the face of uncertainty, and how much do we want to avoid a high cost–low probability worst-case scenario? Given the how high the costs would be, we should be fairly risk averse.”
Not every climate expert is impressed with the new study’s conclusions. Kevin Trenberth, who is part of the Climate Analysis Section at the US National Center for Atmospheric Research, told Salon by email that the new report is “a bunch of total BS. They do not refer to any of our publications about the Atlantic and what is going on there and they get it all wrong.” He added that based on “the best and longe[st] record than they have, the N[orth] Atlantic is dominated by natural variability and they can not say anything about the longer term changes.”
American atmospheric scientist Ken Caldeira also warned against overstating the situation with AMOC. He wrote to Salon that “it should also be noted that paleo-climate data indicates that a shut-down of the North Atlantic circulation may have more widespread consequences than is predicted by the climate models.” The problem is that even our most sophisticated climate models do not contain enough details to be able to anticipate with certainty what is going to happen in our climate system.
Like Proistosescu, Caldeira urged erring on the side of being safe. “In this case, uncertainty means risk, and, because effects of our CO2 emissions are effectively irreversible, this risk should motivate a high degree of caution,” he concluded.
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.
