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Ocean currents moving heat are growing closer to collapse, study says

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An abrupt shutdown of Atlantic Ocean currents that could put large parts of Europe in a deep freeze is looking a bit more likely and closer than before as a new complex computer simulation finds a “cliff-like” tipping point looming in the future.

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A long-worried nightmare scenario, triggered by Greenland’s ice sheet melting from global warming, still is at least decades away if not longer, but maybe not the centuries that it once seemed, a new study in Friday’s Science Advances finds. The study, the first to use complex simulations and include multiple factors, uses a key measurement to track the strength of vital overall ocean circulation, which is slowing.

 

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The Atlantic Meridional Overturning Circulation

(Photo: Shutterstock)

A collapse of the current – called the Atlantic Meridional Overturning Circulation or AMOC – would change weather worldwide because it means a shutdown of one of key the climate and ocean forces of the planet.

It would plunge northwestern European temperatures by 9°F to 27°F (5°C to 15°C) over the decades, extend Arctic ice much farther south, turn up the heat even more in the Southern Hemisphere, change global rainfall patterns and disrupt the Amazon, the study said. Other scientists said it would be a catastrophe that could cause worldwide food and water shortages.

“We are moving closer (to the collapse), but we we’re not sure how much closer,” said study lead author Rene van Westen, a climate scientist and oceanographer at Utrecht University in the Netherlands. “We are heading toward a tipping point.”

When this global weather calamity – grossly fictionalized in the movie “The Day After Tomorrow” – may happen is “the million-dollar question, which we unfortunately can’t answer at the moment,” van Westen said. He said it’s likely a century away but still could happen in his lifetime. He just turned 30.

“It also depends on the rate of climate change we are inducing as humanity,” van Westen said.

 

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המסת קרחונים בגרינלנדהמסת קרחונים בגרינלנד

Melting ice sheets in Greenland

(Photo: Shutterstock)

Studies have shown the AMOC to be slowing, but the issue is about a complete collapse or shutdown. The United Nations’ Intergovernmental Panel on Climate Change, which is a group of hundreds of scientists that gives regular authoritative updates on warming, said it has medium confidence that there will not be a collapse before 2100 and generally downplayed disaster scenarios. But van Westen, several outside scientists and a study last year say that may not be right.

Stefan Rahmstorf, head of Earth Systems Analysis at the Potsdam Institute for Climate Research in Germany, was not part of the research, but called it “a major advance in AMOC stability science.”

“The new study adds significantly to the rising concern about an AMOC collapse in the not too distant future,” Rahmstorf said in an email. “We will ignore this at our peril.”

University of Exeter climate scientist Tim Lenton, also not part of the research, said the new study makes him more concerned about a collapse.

An AMOC collapse would cause so many ripples throughout the world’s climate that are “so abrupt and severe that they would be near impossible to adapt to in some locations,” Lenton said.

 

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Atlantic Ocean Atlantic Ocean

Atlantic Ocean

(Photo: Reuters)

There are signs showing that the AMOC has collapsed in the past, but when and how it will change in the future is still uncertain, said U.S. National Oceanic and Atmospheric Administration oceanographer Wei Cheng, who wasn’t part of the research.

The AMOC is part of an intricate global conveyor belt of ocean currents that move different levels of salt and warm water around the globe at different depths in patterns that helps regulate Earth’s temperature, absorbs carbon dioxide and fuels the water cycle, according to NASA.

When the AMOC shuts down, there’s less heat exchanged across the globe and “it really impacts Europe quite severely,” van Westen said.

For thousands of years, Earth’s oceans have relied on a circulation system that runs like a conveyor belt. It’s still going, but slowing.

The engine of this conveyor belt is off the coast of Greenland, where, as more ice melts from climate change, more freshwater flows into the North Atlantic and slows everything down, van Westen said. In the current system, cold, deeper, fresher water heads south past both Americas and then east past Africa.

Meanwhile saltier warmer ocean water, coming from the Pacific and Indian oceans, pushes past the southern tip of Africa, veers to and around Florida and continues up the U.S. East Coast on up to Greenland.

 

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קרחון נמס בקנגרטיטיווק שבגרינלנד, שם הטמפרטורות עולות פי ארבעה מהר מהממוצע העולמיקרחון נמס בקנגרטיטיווק שבגרינלנד, שם הטמפרטורות עולות פי ארבעה מהר מהממוצע העולמי

Meltin ice sheet in Greenland

(Photo: AFP)

The Dutch team simulated 2,200 years of its flow, adding in what human-caused climate change does to it. They found after 1,750 years “an abrupt AMOC collapse,” but so far are unable to translate that simulated timeline to Earth’s real future. Key to monitoring what happens is a complicated measurement of flow around the tip of Africa. The more negative that measurement, the slower AMOC runs.

“This value is getting more negative under climate change,” van Westen said. When it reaches a certain point it’s not a gradual stop but something that is “cliff-like,” he said.

The world should pay attention to potential AMOC collapse, said Joel Hirschi, division leader at the United Kingdom’s National Oceanography Centre. But there’s a bigger global priority, he said.

“To me, the rapidly increasing temperatures we have been witnessing in recent years and associated temperature extremes are of more immediate concern than the AMOC shutting down,” Hirschi said. “The warming is not hypothetical but is already happening and impacting society now.”

 

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Here’s how Helene and other storms dumped a whopping 40 trillion gallons of rain on the South

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More than 40 trillion gallons of rain drenched the Southeast United States in the last week from Hurricane Helene and a run-of-the-mill rainstorm that sloshed in ahead of it — an unheard of amount of water that has stunned experts.

That’s enough to fill the Dallas Cowboys’ stadium 51,000 times, or Lake Tahoe just once. If it was concentrated just on the state of North Carolina that much water would be 3.5 feet deep (more than 1 meter). It’s enough to fill more than 60 million Olympic-size swimming pools.

“That’s an astronomical amount of precipitation,” said Ed Clark, head of the National Oceanic and Atmospheric Administration’s National Water Center in Tuscaloosa, Alabama. “I have not seen something in my 25 years of working at the weather service that is this geographically large of an extent and the sheer volume of water that fell from the sky.”

The flood damage from the rain is apocalyptic, meteorologists said. More than 100 people are dead, according to officials.

Private meteorologist Ryan Maue, a former NOAA chief scientist, calculated the amount of rain, using precipitation measurements made in 2.5-mile-by-2.5 mile grids as measured by satellites and ground observations. He came up with 40 trillion gallons through Sunday for the eastern United States, with 20 trillion gallons of that hitting just Georgia, Tennessee, the Carolinas and Florida from Hurricane Helene.

Clark did the calculations independently and said the 40 trillion gallon figure (151 trillion liters) is about right and, if anything, conservative. Maue said maybe 1 to 2 trillion more gallons of rain had fallen, much if it in Virginia, since his calculations.

Clark, who spends much of his work on issues of shrinking western water supplies, said to put the amount of rain in perspective, it’s more than twice the combined amount of water stored by two key Colorado River basin reservoirs: Lake Powell and Lake Mead.

Several meteorologists said this was a combination of two, maybe three storm systems. Before Helene struck, rain had fallen heavily for days because a low pressure system had “cut off” from the jet stream — which moves weather systems along west to east — and stalled over the Southeast. That funneled plenty of warm water from the Gulf of Mexico. And a storm that fell just short of named status parked along North Carolina’s Atlantic coast, dumping as much as 20 inches of rain, said North Carolina state climatologist Kathie Dello.

Then add Helene, one of the largest storms in the last couple decades and one that held plenty of rain because it was young and moved fast before it hit the Appalachians, said University of Albany hurricane expert Kristen Corbosiero.

“It was not just a perfect storm, but it was a combination of multiple storms that that led to the enormous amount of rain,” Maue said. “That collected at high elevation, we’re talking 3,000 to 6000 feet. And when you drop trillions of gallons on a mountain, that has to go down.”

The fact that these storms hit the mountains made everything worse, and not just because of runoff. The interaction between the mountains and the storm systems wrings more moisture out of the air, Clark, Maue and Corbosiero said.

North Carolina weather officials said their top measurement total was 31.33 inches in the tiny town of Busick. Mount Mitchell also got more than 2 feet of rainfall.

Before 2017’s Hurricane Harvey, “I said to our colleagues, you know, I never thought in my career that we would measure rainfall in feet,” Clark said. “And after Harvey, Florence, the more isolated events in eastern Kentucky, portions of South Dakota. We’re seeing events year in and year out where we are measuring rainfall in feet.”

Storms are getting wetter as the climate change s, said Corbosiero and Dello. A basic law of physics says the air holds nearly 4% more moisture for every degree Fahrenheit warmer (7% for every degree Celsius) and the world has warmed more than 2 degrees (1.2 degrees Celsius) since pre-industrial times.

Corbosiero said meteorologists are vigorously debating how much of Helene is due to worsening climate change and how much is random.

For Dello, the “fingerprints of climate change” were clear.

“We’ve seen tropical storm impacts in western North Carolina. But these storms are wetter and these storms are warmer. And there would have been a time when a tropical storm would have been heading toward North Carolina and would have caused some rain and some damage, but not apocalyptic destruction. ”

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Follow AP’s climate coverage at https://apnews.com/hub/climate

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Follow Seth Borenstein on Twitter at @borenbears

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Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.

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‘Big Sam’: Paleontologists unearth giant skull of Pachyrhinosaurus in Alberta

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It’s a dinosaur that roamed Alberta’s badlands more than 70 million years ago, sporting a big, bumpy, bony head the size of a baby elephant.

On Wednesday, paleontologists near Grande Prairie pulled its 272-kilogram skull from the ground.

They call it “Big Sam.”

The adult Pachyrhinosaurus is the second plant-eating dinosaur to be unearthed from a dense bonebed belonging to a herd that died together on the edge of a valley that now sits 450 kilometres northwest of Edmonton.

It didn’t die alone.

“We have hundreds of juvenile bones in the bonebed, so we know that there are many babies and some adults among all of the big adults,” Emily Bamforth, a paleontologist with the nearby Philip J. Currie Dinosaur Museum, said in an interview on the way to the dig site.

She described the horned Pachyrhinosaurus as “the smaller, older cousin of the triceratops.”

“This species of dinosaur is endemic to the Grand Prairie area, so it’s found here and nowhere else in the world. They are … kind of about the size of an Indian elephant and a rhino,” she added.

The head alone, she said, is about the size of a baby elephant.

The discovery was a long time coming.

The bonebed was first discovered by a high school teacher out for a walk about 50 years ago. It took the teacher a decade to get anyone from southern Alberta to come to take a look.

“At the time, sort of in the ’70s and ’80s, paleontology in northern Alberta was virtually unknown,” said Bamforth.

When paleontogists eventually got to the site, Bamforth said, they learned “it’s actually one of the densest dinosaur bonebeds in North America.”

“It contains about 100 to 300 bones per square metre,” she said.

Paleontologists have been at the site sporadically ever since, combing through bones belonging to turtles, dinosaurs and lizards. Sixteen years ago, they discovered a large skull of an approximately 30-year-old Pachyrhinosaurus, which is now at the museum.

About a year ago, they found the second adult: Big Sam.

Bamforth said both dinosaurs are believed to have been the elders in the herd.

“Their distinguishing feature is that, instead of having a horn on their nose like a triceratops, they had this big, bony bump called a boss. And they have big, bony bumps over their eyes as well,” she said.

“It makes them look a little strange. It’s the one dinosaur that if you find it, it’s the only possible thing it can be.”

The genders of the two adults are unknown.

Bamforth said the extraction was difficult because Big Sam was intertwined in a cluster of about 300 other bones.

The skull was found upside down, “as if the animal was lying on its back,” but was well preserved, she said.

She said the excavation process involved putting plaster on the skull and wooden planks around if for stability. From there, it was lifted out — very carefully — with a crane, and was to be shipped on a trolley to the museum for study.

“I have extracted skulls in the past. This is probably the biggest one I’ve ever done though,” said Bamforth.

“It’s pretty exciting.”

This report by The Canadian Press was first published Sept. 25, 2024.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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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.”

The Canadian Press. All rights reserved.

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