A crucial system of currents in the Atlantic Ocean that helps control temperatures in the Northern Hemisphere and has implications for the entire planet’s weather systems is showing signs of instability due to human-made climate change, scientists say.
Its collapse would have dire consequences for our weather and life on Earth.
The Atlantic Meridional Overturning Circulation (AMOC) — which the Gulf Stream is a major part of — helps maintain the energy balance in the Atlantic Ocean. It is often described as a “conveyor belt” that takes warm surface water from the tropics and distributes it to the north Atlantic. The colder, saltier water then sinks and flows south.
A study, published Thursday in Nature and Climate Change, warned of “an almost complete loss of stability of the AMOC over the course of the last century. Researchers say it could be close to a collapse from a strong circulation to a weak circulation, though the threshold for such a collapse is still uncertain.
Scientists have warned for years that the circulation is weakening. Heavy rain and melting ice sheets are making the water in the North Atlantic Ocean less salty, which makes it lighter and less likely to sink. If the water in this region becomes too light, the entire circulation could be disrupted.
Global weather patterns are critically linked to the circulation and its transport of heat and nutrients around the planet. A collapse of this system would result in significant and abrupt changes, including fast sea level rise, more extreme winters in Western Europe and disruptions to monsoon systems in the tropics.
It could also have a cascading effect and destabilize other components of the Earth’s climate system, including the Antarctic ice sheet and the Amazon rainforest.
This scenario was the premise for the 2004 climate science fiction film “The Day After Tomorrow,” in which a series of extreme weather disasters strike after climate change caused the AMOC to collapse.
The circulation is weaker than it has been in around 1,000 years, scientists had previously said, but they did not know whether it had actually been destabilized or undergoing natural changes. This week’s study used eight datasets looking at surface temperatures and salinity in the North Atlantic over a period of 150 years, and found global warming was driving the destabilization.
“The difference is crucial,” the study’s author, Niklas Boers from the Potsdam Institute for Climate Impact Research, told CNN in an email.
“Imagine a chair, which can be either shifted (with all four legs remaining on the ground) or tilted. Both change the position of the chair (corresponding to the change in mean AMOC strength), but in the first case the stability of the chair won’t be affected, while in the latter case there exists a critical point. If we tilt the chair just slightly further, it will fall down. My results suggest that what is happening to the AMOC is more likely to be a tilting than only a shifting, so the AMOC has moved toward the critical threshold at which it may collapse,” he said.
Boers added that he himself was surprised by his findings that the AMOC had been destabilized and was “moving toward its critical threshold, at which it could abruptly collapse.”
A collapse of the circulation would mean significant cooling in Europe, Beors said, “but maybe more concerning is the effect of an AMOC collapse on the tropical monsoon systems of South America, Western Africa, and India; especially in Western Africa, an AMOC collapse could lead to permanent drought conditions.”
Boers recognizes in his study that he and other scientists still don’t know if and when the current might collapse, but he called on the world to reduce greenhouse gas emissions “as much and as quickly as possible.”
“Every gram of extra greenhouse gas in the atmosphere will increase to the probability of an AMOC collapse in the future, so emitting as little as possible, both on individual but of course also on collective and international level, is the key.”
The study comes ahead of a major report by the UN’s International Panel on Climate Change on Monday, which has been years in the making and is expected to provide the most conclusive look yet at the extent of human-made climate change. It will also likely paint a picture of what the future could look like, depending on what action the world takes to reduce its greenhouse gas emissions.
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.
