Saturday, November 06, 2021

Ice on the edge of survival: Warming is changing the Arctic


By SETH BORENSTEIN
today

1 of 7
FILE - Broken blocks of sea ice emerge from under the hull of the Finnish icebreaker MSV Nordica as it sails through the Victoria Strait while traversing the Arctic's Northwest Passage, Friday, July 21, 2017. The Arctic is warming three times faster than the rest of the planet and is on such a knife’s edge of survival that the 2021 U.N. climate negotiations in Scotland could make the difference between ice and water at the top of the world in the same way that a couple of tenths of a degree matter around the freezing mark, scientists say. (AP Photo/David Goldman, File)

While conducting research in Greenland, ice scientist Twila Moon was struck this summer by what climate change has doomed Earth to lose and what could still be saved.

The Arctic is warming three times faster than the rest of the planet and is on such a knife’s edge of survival that the U.N. climate negotiations underway in Scotland this week could make the difference between ice and water at the top of the world in the same way that a couple of tenths of a degree matter around the freezing mark, scientists say.

Arctic ice sheets and glaciers are shrinking, with some glaciers already gone. Permafrost, the icy soil that traps the potent greenhouse gas methane, is thawing. Wildfires have broken out in the Arctic. Siberia even hit 100 degrees Fahrenheit (38 degrees Celsius). Even a region called the Last Ice Area showed unexpected melting this year.

In the next couple of decades, the Arctic is likely to see summers with no sea ice.

As she returns regularly to Greenland, Moon, a researcher with the U.S. National Snow and Ice Data Center, said she finds herself “mourning and grieving for the things we have lost already” because of past carbon dioxide emissions that trap heat.

But the decisions we make now about how much more carbon pollution Earth emits will mean “an incredibly large difference between how much ice we keep and how much we lose and how quickly,” she said.

The fate of the Arctic looms large during the climate talks in Glasgow — the farthest north the negotiations have taken place — because what happens in the Arctic doesn’t stay in the Arctic. Scientists believe the warming there is already contributing to weather calamities elsewhere around the world.

“If we end up in a seasonally sea ice-free Arctic in the summertime, that’s something human civilization has never known,” said former NASA chief scientist Waleed Abdalati, who runs the University of Colorado’s environment program. “That’s like taking a sledgehammer to the climate system.”

What’s happening in the Arctic is a runaway effect.

“Once you start melting, that kind of enhances more melt,” said University of Manitoba ice scientist Julienne Stroeve.

When covered with snow and ice, the Arctic reflects sunlight and heat. But that blanket is dwindling. And as more sea ice melts in the summer, “you’re revealing really dark ocean surfaces, just like a black T-shirt,” Moon said. Like dark clothing, the open patches of sea soak up heat from the sun more readily

Between 1971 and 2019, the surface of the Arctic warmed three times faster than the rest of the world, according to the Arctic Monitoring and Assessment Program.


An iceberg delivered by members of Arctic Basecamp is placed on show near the COP26 U.N. Climate Summit in Glasgow, Scotland, Friday, Nov. 5, 2021. The four ton block of ice, originally part of a larger glacier, was brought from Greenland to Glasgow by climate scientists from Arctic Basecamp as a statement to world leaders of the scale of the climate crisis and a visible reminder of what Arctic warming means for the planet. (AP Photo/Alastair Grant)
 

The result?


“The Arctic isn’t just changing in temperature,” Abdalati said. “It’s changing in state. It’s becoming a different place.”

The 2015 Paris climate agreement set a goal of limiting the warming of the Earth to 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-industrial temperatures, or, failing that, keeping it under 2 degrees Celsius (3.6 degrees Fahrenheit). The world has already gotten 1.1 degrees Celsius (2 degrees Fahrenheit) warmer since the late 1800s.

The difference between what happens at 1.5 degrees and 2 degrees can hit the Arctic harder than the rest of the world, University of Alaska Fairbanks climate scientist John Walsh, a member of the Arctic monitoring team. “We can save the Arctic, or at least preserve it in many ways, but we’re going to lose that if we go above 1.5.”

The Arctic itself has blown past 2 degrees Celsius of warming, Stroeve said. It’s approaching 9 degrees Celsius (16 degrees Fahrenheit) of warming in November, she said.

For John Waghiyi Jr., the Arctic is not a number or an abstraction. It’s been home for 67 years, and he and other native Bering Sea elders have watched the Arctic change because of warming. The sea ice, which allows humans and polar bears to hunt, is shrinking in the summer.

“The ice is very dangerous nowadays. It’s very unpredictable,” said Waghiyi of Savoonga, Alaska. “The ice pack affects us all, spiritually, culturally and physically, as we need to have it in order to keep harvesting.”

The ice is “at the core of our identity,” said Dalee Sambo Dorough, international chair of the Inuit Circumpolar Council, representing 165,000 people in several nations.

This isn’t just a problem for people living in the Arctic. It spells trouble for regions much farther south.

An increasingly large number of studies link Arctic changes to alterations of the jet stream — the river of air that moves weather from west to east — and other weather systems. And those changes, scientists say, can contribute to more extreme weather events, such as floods, drought, the February Texas freeze, or more severe wildfires.

Also, the melting of ice sheets and glaciers can add considerably to rising sea levels.

“The fate of places like Miami are tied very closely to the fate of the Greenland,” said David Balton, director of the U.S. Arctic Executive Steering Committee, which coordinates U.S. domestic regulations involving the Arctic and deals with other northern nations. “If you live in Topeka, Kansas, or if you live in California. If you live in Nigeria, your life is going to be affected. ... The Arctic matters on all sorts of levels.”

___

Read stories on climate issues by The Associated Press at https://apnews.com/hub/climate.

___

Follow Seth Borenstein on Twitter at @borenbears.

___

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

EXPLAINER: How warming affects Arctic sea ice, polar bears

By SETH BORENSTEIN, CAMILLE FASSETT and KATI PERRY


This 2020 photo provided by Polar Bears International shows a polar bear in Churchill, Manitoba, Canada during migration. At risk of disappearing, the polar bear is dependent on something melting away on our warming planet: sea ice. 
(Kieran McIver/Polar Bears International via AP)

Majestic, increasingly hungry and at risk of disappearing, the polar bear is dependent on something melting away on our warming planet: sea ice.

In the harsh and unforgiving Arctic, where frigid cold is not just a way of life but a necessity, the polar bear stands out. But where it lives, where it hunts, where it eats — it’s disappearing underfoot in the crucial summertime.

“They have just always been a revered species by people, going back hundreds and hundreds of years,” said longtime government polar bear researcher Steve Amstrup, now chief scientist for Polar Bear International. “There’s just something special about polar bears.”

Scientists and advocates point to polar bears, marked as “threatened” on the endangered species list, as the white-hot warning signal for the rest of the planet — “the canary in the cryosphere.” As world leaders meet in Glasgow, Scotland, to try to ramp up efforts to curb climate change, the specter of polar bears looms over them.

United Nations Environment Program head Inger Andersen used to lead the International Union for the Conservation of Nature, which monitors and classifies species in trouble. She asks: “Do we really want to be the generation that saw the end of the ability of something as majestic as the polar bear to survive?”

THE STATE OF SEA ICE

Arctic sea ice — frozen ocean water — shrinks during the summer as it gets warmer, then forms again in the long winter. How much it shrinks is where global warming kicks in, scientists say. The more the sea ice shrinks in the summer, the thinner the ice is overall, because the ice is weaker first-year ice.

Julienne Stroeve, a University of Manitoba researcher, says summers without sea ice are inevitable. Many other experts agree with her.

Former NASA chief scientist Waleed Abdalati, now a top University of Colorado environmental researcher, is one of them.

“That’s something human civilization has never known,” Abdalati said. “That’s like taking a sledgehammer to the climate system and doing something huge about it.”

The warming already in the oceans and in the air is committed — like a freight train in motion. So, no matter what, the Earth will soon see a summer with less than 1 million square kilometers of sea ice scattered in tiny bits across the Arctic.

The big question is when the Arctic will “look like a blue ocean,” said Mark Serreze, director of the National Snow and Ice Data Center.

Maybe as early as the 2030s, most likely in the 2040s and almost assuredly by the 2050s, experts say.

The Arctic has been warming twice as fast as the rest of the world. In some seasons, it has warmed three times faster than the rest of the globe, said University of Alaska at Fairbanks scientist John Walsh.

That’s because of something called “Arctic amplification.” Essentially, white ice in the Arctic reflects heat. When it melts, the dark sea absorbs much more heat, which warms the oceans even more quickly, scientists say.

THE POLAR BEAR CONNECTION


There are 19 different subpopulations of polar bears in the Arctic. Each is a bit different. Some are really in trouble, especially the southernmost ones, while others are pretty close to stable. But their survival from place to place is linked heavily to sea ice.

“As you go to the Arctic and see what’s happening with your own eyes ... it’s depressing,” said University of Washington marine biologist Kristin Laidre, who has studied polar bears in Baffin Bay.

Shrinking sea ice means shrinking polar bears, literally.

In the summertime, polar bears go out on the ice to hunt and eat, feasting and putting on weight to sustain them through the winter. They prefer areas that are more than half covered with ice because it’s the most productive hunting and feeding grounds, Amstrup said. The more ice, the more they can move around and the more they can eat.

Just 30 or 40 years ago, the bears feasted on a buffet of seals and walrus on the ice.

In the 1980s, “the males were huge, females were reproducing regularly and cubs were surviving well,” Amstrup said. “The population looked good.”

With ice loss, the bears haven’t been doing as well, Amstrup said. One sign: A higher proportion of cubs are dying before their first birthdays.

Polar bears are land mammals that have adapted to the sea. The animals they eat — seals and walruses mostly — are aquatic.

The bears fare best when they can hunt in shallow water, which is typically close to land.

“When sea ice is present over those near-shore waters, polar bears can make hay,” Amstrup said.

But in recent years the sea ice has retreated far offshore in most summers. That has forced the bears to drift on the ice into deep waters — sometimes nearly a mile deep — that are devoid of their prey, Amstrup said.

Off Alaska, the Beaufort Sea and Chukchi Sea polar bears provide a telling contrast.

Go 30 to 40 miles offshore from Prudhoe Bay in the Beaufort Sea “and you’re in very unproductive waters,” Amstrup said.

Further south in the Chukchi, it’s shallower, which allows bottom-feeding walruses to thrive. That provides food for polar bears, he said.

“The bears in the Chukchi seem to be faring pretty well because of that additional productivity,” Amstrup said. But the bears of the Beaufort “give us a real good early warning of where this is all coming to.”

THE FUTURE

Even as world leaders meet in Scotland to try to ratchet up the effort to curb climate change, the scientists who monitor sea ice and watch the polar bears know so much warming is already set in motion.

There’s a chance, if negotiators succeed and everything turns out just right, that the world will once again see an Arctic with significant sea ice in the summer late this century and in the 22nd century, experts said. But until then “that door has been closed,” said Twila Moon, a National Snow and Ice Data Center scientist.

So hope is melting too.

“It’s near impossible for us to see a place where we don’t reach an essentially sea ice-free Arctic, even if we’re able to do the work to create much, much lower emissions” of heat-trapping gases, Moon said. “Sea ice is one of those things that we’ll see reach some pretty devastating lows along that path. And we can already see those influences for polar bears.”


VIDEO
Second Quote_2.mp4 from AP Enterprise and Investigations on Vimeo

MULTIMEDIA PRESENTATION
Arctic sea ice is disappearing and it’s harming polar bears (apnews.com)


___

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

Fassett, a data journalist based in Oakland, California, is a corps member for The Associated Press/Report for America Statehouse News Initiative. Report for America is a nonprofit national service program that places journalists in local newsrooms to report on under-covered topics.




No comments:

Post a Comment