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The ocean is about to flip a switch that could permanently disrupt life on Earth: study – Salon

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A massive Atlantic Ocean current system, which affects climate, sea levels and weather systems around the world, may be about to be fatally disrupted.

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.

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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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