At a Glance
- New research studied satellite images of "The Last Ice Area."
- Seasonal ice that usually holds older ice in place is disappearing sooner each year.
- The region is home to polar bears and narwhals.
The oldest and thickest sea ice in the world might not be as invincible to global warming as scientists once thought.
The region known as "The Last Ice Area" encompasses hundreds of thousands of square miles of ocean along the upper edges of the Canadian Arctic Archipelago and Greenland. It's long believed it could be the only Arctic ice that stays frozen year-round as the impacts of a warmer planet take hold.
But a new analysis of satellite data shows that a seasonal buildup of ice each year in the Nares Strait between Greenland and Canada's Ellesmere Island that usually helps hold the thicker, older ice in place is becoming less stable and not lasting as long as previous years.
The study was published this week in the journal Nature Communications.
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The seasonal ice builds up each year during cooler weather when multiple ice floes converge into the narrow strait, forming huge structures known as arches. When the arches melt in spring and summer, ice can escape through the passage. How much ice is lost each year depends on how long the arches stay in place.
"The duration of arch formation has decreased over the past 20 years, while the mass of ice exported through Nares Strait has increased," study co-author Kent Moore, a professor at the University of Toronto Mississauga, said in a news release.
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"They used to persist for about 200 days and now they’re persisting for about 150 days. There’s quite a remarkable reduction."
Moore added: "We think that it’s related to the fact the ice is just thinner, and thinner ice is less stable."
Last year, Arctic sea ice shrunk to its second-lowest summertime level since satellites began measuring changes in the ice 42 years ago. Only one other year on record, 2012, saw more seasonal ice melt.
The Nares Strait ice arch collapsed early in 2008, 2010, 2017 and 2019, according to NASA's Earth Observatory. The arch didn't form at all in 2007.
Scientists have been counting on The Last Ice Area to last long enough to help buffer against predictions that the Arctic could be ice-free in the summer within the next 30 years due to the impacts of global warming.
"This very old ice is what we’re concerned about," Moore said. "The hope is that this area will persist into the middle part of this century or even longer. And then, hopefully, we'll eventually be able to cool the planet down. The ice will start growing again, and then this area can act as a sort of seed."
In addition to its potential role in climate change, about one-fourth of the world's polar bear population lives in The Last Ice Area and most of the world's narwhals spend at least part of the year there, according to the World Wildlife Fund.
"The scale is so huge and the region is so remote," Moore said. "The only thing we can do is cool the planet down."
The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.
