Steve Connor / The Guardian & Associated Press & Lars Ostenfeld / The Guardian – 2017-01-12 02:03:01
Thawing Arctic Is Turning Oceans into Graveyards
Steve Connor / The Guardian
(January 8, 2017) â€“ Something is happening to the floating sea ice of the Arctic, other than the well-documented retreat in its surface coverage each summer. Scientists are finding that Arctic sea ice is getting younger and thinner, which is set to continue in March, when US research reveals the winter maximum, and September, when it reveals the summer minimum, making it more vulnerable to a catastrophic and unprecedented break-up.
NASA researchers have found that the thicker multi-year ice, which has survived several summer melt seasons, is being rapidly replaced by thinner, more ephemeral one-year ice formed over a single winter. This change makes the polar region increasingly vulnerable to storms that could smash their way through the final remnants of thinner, one-year sea ice, making a completely ice-free summer in the Arctic increasingly likely.
An unpublished study of changes to the multi-year ice over the past few decades has revealed that a part of the Arctic that should be a “nursery” for older ice has in recent years turned into a “graveyard”. Instead of multi-year ice forming within the Beaufort Gyre, a huge circular movement of ice off the coast of northern Alaska and Canada, it is now melting away within this critical region.
The result is that while older, multi-year ice typically made up more than 20% of Arctic sea ice in the 1980s, it now comprises just 3% and what little multi-year ice is left behind is behaving like the crushed ice of a cocktail, more prone to being pushed about and melting compared to a solid ice cube.
The loss of multi-year ice is important because it forms an important bulwark against further ice loss as the region gets warmer, says Walt Meier, a sea ice specialist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who studies the loss of multi-year ice with the help of satellite imagery.
“In the past, the seasonal ice loss in summer would tend to stop when it got to the multi-year ice because it’s three to four metres thick. You couldn’t melt that much ice in summertime, but now what’s happening is that things are getting more broken up,” Meier said.
“Multi-year ice is more fragmented so now you are getting warm water attacking it from all sides. Previously, it was a consolidated ice pack, like a wall of multi-year ice where warm water may melt it a little bit at the edges. But now you are getting big chunks of individual floes sitting there, floating round, surrounded by water that has been warmed by summer sunlight.
“The ice is getting thinner and the winds can more easily break it up. Once broken up, the winds can push it more easily. That just breaks things even further.”
Arctic sea ice, the vital seal-hunting platform of the polar bear, is considered important for the wider climate because it reflects sunlight back into space. The more it melts, the more open ocean there is to soak up sunlight, raising regional temperatures even further.
The Beaufort Gyre is traditionally where much of the multi-year ice forms, Meier said. Its circular winds and currents spin in a clockwise direction, keeping sea ice confined within the colder Arctic region, preventing it from slipping out into the warmer north Atlantic via the Fram Strait, separating Greenland and Svalbard.
Since about the mid-2000s, the circular movement of sea ice in the Beaufort Gyre has speeded up, indicating that this multi-year ice is more “slushy” and fragmented. At the same time, older ice within the gyre has melted, attacked in different directions by warm water.
“Now we’re seeing the thicker, multi-year ice melting out completely, particularly in the Beaufort and Chukchi seas, so it’s getting harder for that multi-year ice to survive. The Beaufort Gyre was like a nursery for the older ice and now it has become sort of like a graveyard where the ice is spinningâ€¦ surrounded by warm water,” he said.
Computer models in the past predicted the first sea ice-free summers in the Arctic occurring mid-century, but these models have assumed a smooth loss of ice as it melts, rather than a catastrophic break-up. Now many scientists predict the first summers free of Arctic sea ice could occur within the next 10 to 15 years.
“You’re going to get the first ice-free summer when you have an extreme summer, almost by definition. But with this break-up of ice cover and loss of multi-year ice, the system is becoming more vulnerable to extreme summers,” Meier said.
“The ice has become more vulnerable to the weather and so more vulnerable to extremes. In that sense, things have definitely changed and it makes things less predictable in many ways because you can’t predict when or where the next storm is going to hit.
“We’re obviously heading for a sea ice-free Arctic at some point, but which year it happens may very much depend on a big enough storm happening in the right year at the right time.”
Although we may not see a sea ice-free Arctic this summer, we are likely to see the continued loss of multi-year ice that makes that event more and more imminent.
US Plans to Save Polar Bears are Toothless, Says Climate Scientist
The Guardian & Associated Press
ANCHORAGE (January 9, 2017) — The US Fish and Wildlife Service has released its plan for the recovery of threatened polar bears, acknowledging it will take no direct action to address the primary threat of greenhouse gases on the decline of sea ice habitat.
Polar bears, the first species to be declared threatened or endangered because of climate change, rely on sea ice for hunting seals and raising their young. Climate models project that rising temperatures will continue to diminish sea ice throughout this century.
The plan announced on Monday calls for reduced greenhouse gas emissions but focuses on action to be taken by the agency on other conservation strategies, such as preventing contamination from spills, protecting dens, or reducing conflicts with humans.
Shaye Wolf, climate science director for the Centre for Biological Diversity, which filed the petition to list polar bears in 2005, called the recovery plan toothless.
The plan, she said, acknowledges polar bears will not survive without cuts in large-scale greenhouse gas pollution. The science in the plan shows the need to keep global temperature rise well below 2C for polar bears to have any reasonable chance of survival, she said.
The agency’s job, she said, is to outline the steps needed to be taken for polar bears to survive. “It acknowledges the problem but fails to put the solution in the core strategy for the bear,” she said.
The agency said addressing increased atmospheric levels of greenhouse gases that result in Arctic warming will require global action. Until that happens, the focus of recovery will be on US wildlife management actions that will contribute to polar bear survival in the interim “so that they are in a position to recover once Arctic warming has been abated”, the plan said.
Dirk Kempthorne, who was secretary of the interior under George Bush, announced in 2008 that polar bears would be listed as threatened under the Endangered Species Act. But he added immediately that endangered species law would not be used to set climate policy or limit greenhouse gas emissions.
This Is the Polar Bear Capital of the World, but the Snow Has Gone
Lars Ostenfeld / The Guardian
(December 20, 2016) — Churchill, on the banks of the Hudson Bay in Canada, is known as the polar bear capital of the world. Hundreds of bears gather there each year before the sea freezes over in October and November so they can hunt seals again from the ice for the first time since the summer.
I first went there 12 years ago at this time of year. The place was white, the temperature was -20C, and the bears were out feeding.
This year I came back to make a film for Danish TV and set up live feeds of the bears. It was so different. In mid-November there was no snow or sea ice or ice; the land was green or brown and the temperature was 2C. The bears were walking around on the land waiting for the ice to form. It was like summer.
October had seen unprecedented temperatures all around the Arctic leading to a record-breaking slowdown of sea ice formation. Local people told me they had never seen it like this before.
With Geoff York, director of conservation at Polar Bears International, we pored over satellite maps every day. It was shocking. The whole 470,000 sq mile bay was completely ice-free.
This is the southernmost colony of polar bears in the world and in the past about 1,000 bears would be there. But studies have shown that in the last 20 years the surface temperature of Hudson Bay has warmed by about 3C.
This has had a massive effect on the bear. The western Hudson Bay population has declined by more than 20% in 30 years. It’s the same elsewhere. New analysis of data from the southern Beaufort Sea in north-west Canada and Alaska suggest even greater population declines there.
We saw about 20 bears around Churchill in the 10 days I was there. That’s actually a few more than I saw last time, when I was there 12 years ago, but that was because most of the bears were out on the ice then. The ones we did see this year appeared thin, restless and hungry, and were starting to be more aggressive.
There was a mum and a cub and it was very emotional because it looked pretty certain that the cub would not survive much longer. The days of bears in this region having triplets seem to be over. The declining sea ice has decreased hunting opportunities, so the bears are smaller and fewer cubs are being born in this area.
Every year, York told us, the bears spend one day more on land and one day less on the ice. That does not sound much, but it’s one day less hunting, and over 30 years they are getting one months’ less food.
The ice is getting thinner; it’s melting earlier and it’s coming later. New studies suggest that polar bears can only survive for about 180 days on shore.
York was clear: “If sea ice loss continues at the same pace or faster than we have seen here over the last 30 years, this is definitely not sustainable and researchers predict polar bears could become regionally extinct by mid- to end of this century.”
The polar bear is an icon of climate change. What is happening near Churchill is a clear sign that change is taking place now. When I returned to Europe, the frost finally came. It should have been one month earlier. This is about much more than polar bears. If an animal that is designed to survive here can’t make it, we are in trouble. It’s really about us.
Lars Ostenfeld was talking to John Vidal
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