Beavers are gnawing away at the Arctic permafrost, and that's bad for the planet - CTV News | Canada News Media
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Beavers are gnawing away at the Arctic permafrost, and that's bad for the planet – CTV News

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The beaver may be an unlikely agent of climate change, but the cuddly-looking creatures are transforming the Arctic landscape in a way that could be exacerbating global warming, a new study has suggested.

With their sharp teeth, beavers fell trees and shrubs and build dams, which flood small valleys and form new lakes that can cover several hectares of land.

These new water bodies contribute to the thawing of the frozen permafrost soil, which is a huge natural reservoir of methane — a potent greenhouse gas.

Scientists are concerned that as the permafrost degrades, the climate-changing methane and carbon leak into the atmosphere.

In the past few years, scientists have spotted beavers in the Alaskan tundra where they’ve previously never been seen before — and the animals have been enjoying a dam-building boom in their new neighborhood, according to the study of high-resolution satellite imagery published in the journal Environmental Research Letters Monday.

They also seem to be building their dams and creating new lakes in the very locations that are most likely to intensify the thawing of the permafrost.

“We’re seeing exponential growth there. The number of these structures doubles roughly every four years,” said Ingmar Nitze, a researcher from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research in Potsdam, Germany, and author of the study.

“Their methods are extremely effective.”

The study found that the number of beaver dams in a 100-square-kilometer area surrounding the city of Kotzebue, northwest Alaska, increased from just two in 2002 to 98 in 2019 — a 5,000% increase. Beaver dams in the larger, 430-square-kilometer area on Alaska’s Baldwin Peninsula have increased from 94 in 2010 to 174 in 2013 and 409 last year.

“It’s possible to see them and spot them (the dams) in the imagery. It’s also possible to see the development of lakes. They had a distinctive signal,” said Nitze.

 

BLAME IT ON THE BEAVERS?

 

Several different factors explain why the beavers have occupied a region they wouldn’t normally call home, said Nitze. One is climate change, which is altering the typically treeless tundra.

“We see an increase in vegetation. There are more shrubs coming in there so all the stuff beavers need to build their dams, or as food, is there,” he said. Furthermore, the lakes, which used to freeze solid, now offer friendlier conditions for beavers, as a result of their thinner seasonal winter ice cover

The tundra is also not the beavers’ usual habitat so they face no predators or competition for resources, plus the animals are better protected now by U.S. federal law and hunted far less by humans than they used to be.

Because the lakes the beavers create contain water that is warmer than the surrounding soil, the new bodies of water accelerate the permafrost thawing.

“The thing about permafrost is that water interacts very strongly with the frozen ground beneath it,” Nitze said. “The more surface water you have, the worse it is for the permafrost–because in the winter the cold air cannot penetrate again into the ground, and the water stores a lot of the heat and can even penetrate it into the ground,” he said.

Lakes and water bodies influenced by beavers accounted for two-thirds of the 8.3% increase in total surface water area in the Kotzebue study area during a 17-year period, the study found.

The beavers also seemed to intuitively target drained lake basins, turbocharging the impact they had on the landscape and the permafrost.

“It’s a special landscape. There’s typically a lot of lakes but they are dynamic so they can drain and leave a lot of basins … and these beavers are smart enough to block the outlet and refill the basin again. They dam up a lot of area with minimum effort.”

Nitze said the beaver dam-building boom was also likely taking place in the Canadian tundra, and could also be happening in Siberia.

“We’re working to expand the analysis on a bigger scale.”

Some climate scientists think that we are underestimating the warming effect of the thawing permafrost.

“There are a lot of people trying to quantify methane and CO2 emissions from lakes in the Arctic but not specifically yet from beaver lakes,” said Nitze.

“It’s a very new topic and something we have uncovered over the past few years. Beavers can have a quite significant impact on these landscapes, so there’s no real quantification yet for these lakes but it will be done in the future.”

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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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