New research documents a counterintuitive impact of global warming: sea-ice hazards to shipping

By Tom Yulsman | March 21, 2018 1:48 pm

Human-caused warming is popping the frozen corks that normally bottle up thick sea ice in the Arctic Ocean, allowing it to pour south

Sea-ice hazards

NASA’s Aqua satellite captured these two views of different sea ice conditions over the Lincoln Sea, a part of the Arctic Ocean north of Greenland and Ellesmere Island. Breakup here happened much earlier than usual in 2017, allowing huge volumes of thick sea ice to pour south through a narrow passage and ultimately into the North Atlantic Ocean. (Images: NASA Worldview. Animation: Tom Yulsman)

Ships plying the North Atlantic Ocean in spring are facing increased hazards from floating Arctic sea ice as a result of human-caused global warming.

That might seem counterintuitive, but here’s what’s happening, according to a new study published in the journal Geophysical Research Letters:

Warming temperatures are causing ice that normally blocks narrow ocean passages in winter and spring to break up earlier than in the past. Like a cork removed from a champagne bottle, the early break up in these passages is allowing thick, old sea ice to flow south from the Arctic Ocean into the North Atlantic, choking areas used by fishing, shipping and ferry boats.

“Heavy ice conditions along Canada’s east coast during spring 2017 presented hazardous conditions for the maritime industry at a time of year when vessels typically do not need to contend with sea ice,” the researchers note in their paper. As warming has caused Arctic sea ice to shrink and thin overall:

. . . it has become increasingly mobile. This has contributed to increased ice transport through narrow channels along the periphery of the Arctic Ocean . . . and increased the presence of thick multiyear sea ice from the High Arctic at more southern locations that have typically not contended with such sea ice.

I created the animation above to show what this looks like from orbit. It consists of images centered over the Lincoln Sea, part of the Arctic Ocean — both acquired by NASA’s polar-orbiting Aqua satellite.

The image acquired on June 28th, 2015 shows the Lincoln Sea, and the Nares Strait between Greenland and Canada’s Ellesmere Island. Even in early summer, the area is choked with ice.

Compare that with the image captured on May 25, 2017. Ice in the Lincoln Sea has already broken up, and bergs are pouring to the southwestward through the strait.

The video above, consisting of data from the European Space Agency’s Sentinel 1B satellite, shows the evolution of sea ice in the area between the fall of 2016 and spring of 2017. To my eye, it looks like ice pours through the Nares Strait almost through the entire period.

Sea-ice hazards

Source: Mapswire, CC BY 4.0.

“It’s counterintuitive to most people, because it means you can have an increase in local ice hazards because of a changing climate in the high Arctic,” says the University of Manitoba’s David Barber, lead author of the study, quoted in a release from the American Geophysical Union.

“This is something we need to better prepare for in the future, because we expect this phenomenon to go on for at least a couple more decades as we transition to an ice-free Arctic in the summer.”

In the past, southward flow through narrow channels like the Nares Strait has been delayed until well into summer, thanks to features known as “ice arches.”

Sea-ice hazards

Lifeboats, debris and fishing gear are seen at the site where a fishing vessel sank near Newfoundland in 2017 after becoming trapped in thick sea ice. The vessel’s crew was rescued by the Canadian research icebreaker Amundsen. (Source: David G. Barber)

Previous research has shown that reduced formation of these natural corks has allowed increasing amounts of ice to flow from the central Arctic and Lincoln Sea into Baffin Bay.

The new study extends this body of research, showing that sea ice found around Newfoundland in May and June 2017 likely formed in the Lincoln Sea, 1,800 miles to the north. According to the American Geophysical Union, which published the study:

The unusually thick ice cover took ships by surprise. The ice was much thicker than usual – up to 8 meters (26 feet) thick in some cases. Off the Newfoundland coast, an unprecedented number of ships, fishing vessels and ferry boats became trapped in the ice.

In early June, the Canadian coast guard pulled the research icebreaker Amundsen off its scientific expedition to escort ferries caught in the congested seas to open water, and conduct search and rescue operations for stranded passengers of ferry boats and ships trapped in the ice, as it was the only large icebreaker available at the time.

  • OWilson

    I give up!

    Cold weather is global warming! Ice blocking Canada’s shipping lanes is global warming! More snow is global warming! More rain is global warming! More droughts are global warming!

    Send me the T-Shirt!

    But on my island paradise it may be hard. Where I am, there are no street numbers, no post office, some streets have no name, but everybody is smiling.

    I don’t have the heart to tell them we are all going to be washed away :)

    And to the true believers out there who tell me I live in a “cult commune”, or get paid to post here, or I “am a danger to the continuation of humanity”, I say,

    %$#@%$#$ !!!

    I’m going for a beer!

    Come and get me!


    • TEAB

      We can at least establish trolls like you are not going to be part of the solution – and please leave it to science to explain the problem to anyone else.
      Enjoy your paradise.

      • OWilson

        I’m the problem remember? In your AGW delusional echo chamber world, I’m a deplorable, fascist supporting, Koch paid, cult commune living, danger to the continuation of humanity!

        Even though, in the real world I live quietly in retirement among wonderful friends, with no vehicle, I walk to everything, and eat only locally grown produce, with just about a zero carbon footprint!

        But for the true belivers, whatever makes you feel good and gets you through the day!

        It’s healthy to get those delusional feelings out in the open, so at least I’m serving a good purpose by posting here!

        May you too, find peace!

        • TEAB

          Whoa! Were you waiting for someone to respond to unleash this? If you are agitated because you hardly contribute to the problem, I can relate. But let me explain; your OP you come across as: “I’ve had enough of all the climate change theories. It’s supposed to affect my island, but I don’t feel like sharing the science since this is outside our bubble. Maybe I’m a denier, but you sort it out.”
          Hope that clears up my response. I apologise if I misunderstood you.

          • OWilson

            You may be new here, so you may not be familiar with the last couple of years of conversations here.

            I have been called all those names above, and worse, in the last few weeks, and even told I belong in jail.

            I don’t see that as adding to a solution of any scientific problem!

            My reply was intended to be a wry, sarcastic and satirical comment. Sorry you missed that, maybe I should have put my trademark smiley after it :)

            I can assure you that I am not “agitated” :)

            Anymore than I, an old retired gentleman of modest means, is “a danger to the continuation of humanity” as some have agreed in the previous article :)

            What is it about AGW advocates that makes them so unbalanced?


          • TEAB

            Yeah, use emojis.

          • juanmeden

            Not to worry, OWilson. Global warming enthusiasts think that name-calling is a scientific argument. They do it with anyone who disagrees with them.

          • OWilson

            They believe what their lying politicans tell them to believe!

            The biggest tool any politician ever had is fear! With that you can raise enough money to build a giant military machine to keep you in power!

            From Stalin, through Castro to Kim il Un! :)

          • Rick S.

            OWilson, “they” believe it because “they” want to !


            You forgot “Mao” in the above post ?

            I mean, as the perfect Socialist (Marxist), Mao did murder over [ 100,000,000 (Thats 100 “Million) ] of his “own” people, with Stalin a some what distant second…

            Say what you will though, but those Marxists (Socialists) do a damn fine job of Murdering their “own” people, and in fact it does reduce their own “Carbon” footprint ??? !

            I mean that of the Murderer one’s of course !

            Perfect !

            World Workers [ UNITE ]

            Sincerely yours,

            Ex-President of the United States of America…

            Barack Insane Obama

          • Tom Yulsman

            Rick: I have been dealing with a health issue and so I am just catching up to comments on this thread…. I am not writing to respond substantively to your political comments here. But I do wish to respectfully request that in future comments you focus primarily on science, not politics. I have generally given a wide berth to political diatribes, but Discover is a science magazine, and I would like the comments section to reflect that more than it has. With that in mind, I ask that if you want to equate people with a different political perspective than yourself with Maoism and Stalinism, please do it somewhere else. By contrast, if you have a science-based insight into something I write about here, by all means share it with us. I am asking this respectfully, and I hope you will act in the same spirit by abiding by my request. Thank you.

      • Not_that_anyone_cares, but…

        👎 ᠎

    • robert2365

      You live on an island? Enjoy your short lived delusion.

    • Tom Yulsman

      Mr. OWilson: It is time for you to take a time out from commenting. You are saying the same things over and over again and adding nothing constructive. Let’s give it a couple of weeks.

  • Charlotte Copp

    Are you interested how climate change and remote sensing relate? or want to learn more? If so, please participate in this project, Stories Through the Bird’s Eye: Engaging with Remote Sensing. The aim of this project is to engage around a topic that could be considered debatable, and I want to hear (I really do) what you have to say! So please contribute your ideas!

  • Mike Richardson

    I wouldn’t exactly consider it counterintuitive that warming sea ice would break up and add to the navigational hazards of the northern ocean, but it’s good to see a detailed explanation of the process. Judging from the reaction of the first poster, it’s apparently necessary, since this seems to be a distressing fact to him. Perhaps it should be.

    • Rick S.

      “You” have got to be joking” ???

      Right ?

      Global Warming produces more Sea Ice ?????

      No one can be born this stupid, it must “evolve” over time !

      I’ve got a bridge for sale in Northern California, $10,000 down and it is yours !!!

      Cash Only !

      Purchase Agreement not necessary…

      • Bluetooth

        These AGW people are nuts…they are off their rockers.

      • Mike Richardson

        Read the article. It isn’t making more sea ice — it’s allowing it to break up faster and spread south to become a sea hazard. Reading comprehension is an important skill to develop if you’re going to contribute an informed opinion.

        • Damn Nitpicker

          Nothing new, here. In 2012, cyclonic activity busted up the floating sea-ice and exported it (in iceberg form), a lot out through the Fram Strait. Contrary to popular opinion, it did not melt in the Arctic. That’s the real cause for the abnormal low in Arctic ice in 2012.

          Parkinson & Comiso 2013: ”A new record low Arctic sea ice extent…on 13 September 2012; … Preconditioning, through decades of overall ice reductions, made the ice pack more vulnerable to a strong storm that entered the central Arctic in early August 2012. … left the main pack more exposed to wind and waves, facilitating the main pack’s further decay.”

          Parkinson & Comiso 2013. “On the 2012 record low Arctic sea ice cover: Combined impact of preconditioning and an August storm.” Geophysical Research Letters

          Krumpen 2016: ”Fram Strait is the main gateway for sea ice export out of the Arctic Ocean, … satellite data show that monthly ice area export had positive trends since 1980 (10.9 × 10^3 km^2/decade), the summer (July and August) ice … average volume export amounts to 16.78 km^3. …”

          ”One aspect of the mass balance of Arctic sea ice are changes of ice volume export rates through Fram Strait, the major sea ice outflow gate of the Arctic.”

          ”… the increase in ice export is the consequence of a positive trend in the local pressure gradient, related to intensification of cyclones over the Nordic Seas. … sea ice area export has increased by about 25 % since the 1960s.”

          Krumpen, Thomas, et al. 2016 “Recent summer sea ice thickness surveys in Fram Strait and associated ice volume fluxes.” The Cryosphere

          NSIDC: ”For example, during a positive Arctic Oscillation phase, changes in the wind field help to push ice away from the coast of Siberia, allowing new ice to form, and increasing the transport of ice out of Fram Strait. In the winters of the late 1980s and early 1990s, the Arctic Oscillation was in a persistent positive phase, helping to transport a large amount of thick, multiyear ice out of the Arctic through Fram Strait and leaving behind thinner ice that more easily melted the following summers.”

      • Tom Yulsman

        Rick: As a follow up to my earlier comments, I would also like to request that you refrain from calling people “stupid” and engaging in other forms of name calling and ad hominem attacks. I do ImaGeo in my spare time, so I cannot police things perfectly. But to the extent that I can, I want to elevate the discussion here in ways that are more in keeping with a science magazine. So when you find your anger rising and are tempted to attack people here, please take a breath and try to channel that anger toward being constructive, not destructive. If that’s just not for you, then you should find another outlet for your comments. And I would be remiss in saying that if you cannot find it within yourself to abide by my reasonable requests then you will no longer be allowed to comment here. Please be clear: I am not trying to censor viewpoints with which I disagree. I am trying to maintain some reasonable standards.

  • Joan Galt

    Science uses the scientific method.
    Climate “science” does not use the scientific method.
    Climate “science” uses anecdotal evidence.
    Anecdotal evidence is not science.
    Any questions?

    • Charles Barnard

      Actually, you are so badly mistaken, I wonder where you “learned” what you think you know.

  • Joan Galt

    CORROLARY: Hot weather is climate, cold weather is just weather.

    • Charles Barnard

      Climate is weather history projected forward–you only know what you expect, not what may happen.

      If you knew what the terms meant, you would be much better informed.

  • Terrence Jeffrey Johnson

    More alarmist BS
    Sorry…GloBULL Warling is a HOAX…….

  • Chris Norman

    For years many perfectly respectable scientist have told us that starting in mid solar cycle 24 the planet would begin to cool. Evidence of that cooling started first in the Northern hemisphere and then in mid 2015 we had record cold events in Australia, New Zealand and South America. Record cold events have continue unabated all over the planet are now reported almost daily by local news organisations.
    Many of the afore mentioned scientists tell us we are heading into a full blown Maunder Minimum. That the ocean is now filling with ice is just further evidence that they were right and that AGW is far from the primary driver of climate, if any driver at all.
    I live in NZ were we have enjoyed a fine summer. But even with that we have had summer snow for the last two years. Most of our glaciers are growing again. Tasmania has had two summer blizzards. Perth one of the coldest summer on record. South America has had repeated summer frosts doing much crop damage.
    To those of you convinced of AGW consider this. The Sun consists of 99.8-9% of all of the mass of the solar system. Human mass consist of a number with so many noughts in front of it it could be confused with Absolute zero. It always was no contest.

    • Charles Barnard

      Mass is not a significant indicator of ability to change.

      Prehistoric humans managed to change the climate of the Middle-East and elsewhere quite drastically.

      All it took was time, people, and their livestock.

      If you don’t believe things are changing for the worse, I suggest you latch onto some nice land in the Maldives.

      Places where sea levels have already risen don’t have non-believers…

  • Freddy Boom-Boom

    Yes, Good to have such counterintuitivity so readily explained (and believed w/o question). I knew there had to be an explanation why the AGW theory just keeps plugging along despite what other theories would experience as a falsification of its claims and the actual theory itself. Never mind that such claims where never part of the shrill warnings projected ad nauseum for decades now (until the increase in N. Hemisphere snow cover became impossible to hide over the past decade). Never mind that the IPCC official reports claimed exactly the opposite of this – that snow cover and ice would decline. Never mind that the Sun is now in the quietest minimum phase in the past 200 years. Never mind that solar physicists have been warning since 2009 that this may match one of the historically deep, protracted minima known as (either) the Dalton Minimum (about 1780-1850), or worse still, the Maunder Minimum (abt 1645-1715). Never mind that this toasty little Holocene Period of ours is about 1000 years overdue to end, or that all cooling periods are preceded by a warming period. Or that for the 60 years or so leading up to the year 2000, the Sun had been in it’s most active period in the past 9,500 years. Never mind about any of these things. The simply don’t matter. After all, I obviously hate science and all other good in the world. So never mind.

  • Joop Eelvelt

    More fake news, consider this, there is more snow and ice on Greenland then ever before and the water in the North Atlantic is cooling. And then the term “manmade”, please look for an other occupation.

    • Charles Barnard

      I don’t know where you get your information, but the people living in Greenland disagree as to those scientists studying the ice there.

      N Atlantic water is cooling because it is largely fresh water from melted ice…and it is a problem because it is sitting on top of warmer salt water which will adversely affect both the life and the weather patterns.

      Yes, it’s confusing, changing climate to warm the planet as a whole actually can create colder areas–which is why scientists look at the planet as a whole instead of just outside their windows.

      NOBODY is saying “climate change is all mankind’s fault.”

      Except those who deny that there is change.

      Those who study climate agree that humans are a significant factor in such change–a VERY different statement.

  • Richard Fanning

    Stupid is as stupid publishes!

    • Charles Barnard

      Given your useless and meaning-free comment, you are an expert.

  • Alec Rawls

    “Human-caused warming is popping the frozen corks…”

    To describe the small amount of post 1975 warming as “human caused” is a lunatic fraud. The 100% politically funded IPCC makes the radically unsupported claim that this small amount of warming has been HALF caused by human increments to CO2.l, and it arrives at this claim by baldly assuming that the 80 year grand maximum of solar activity that ended in the early 2000s had no significant warming effect.

    This when the leading theory, before Al Gore’s political funding of climate science took over, was that the Little Ice Age had been caused by the 70 year absence of sunspots called the Maunder Minimum. See Eddy’s 1975 Science article titled “The Maunder Minimum.”

    That theory is supported by the slowdown/pause/cessation of warming since the sun went quiet starting in 2005, while the CO2 theory has been or is on the verge of being falsified by the lack of warming, in contrast to the accelerating warming that the CO2-dominated theory predicts.

    • Charles Barnard

      Actually, no reputable climate people work from “post-1975 warming” as their starting point.

      Please, study the subject before you post.

      Yes, theories change, but that reflects our increases in understanding–not our ignorance.

      Change today is far faster than the Maunder Minimum.

      Also, remember that our solar insolation dropped drastically during the first 80 years of the past century due to pollution–hiding a 2 degree C increase in temperature.

      Human affects on weather provably go back at least 4,000 years, to the beginning of the deforestation of the Middle East.

      Are they the ONLY effects? No, of course not, however tiny, a planetary climate system is affected by thousands of different factors–including how many krill and shrimp are swimming around, the various amounts of heat released from the Earth itself, solar insolation which varies due to the Sun, interstellar dust and weather patterns.

      Do we know for certain what the weather patterns will be? Of course not! Climate is what we expect based upon past weather, what we can expect is changing, since our ability to predict based upon past patterns no longer is very accurate, we KNOW that patterns have and are changing.

      We also know that humans are a large part of the equation–our changes to vegetation cover alone have modified climate heavily since we invented agriculture.

      What we do are also the simplest things to change.

      We are idiots though, because despite the fact that we have known for thousands of years that piling up our waste products is dangerous to us and to other life we depend upon, we continue to poison ourselves.

      If we are unable to change things and they get worse, then we’ll have to deal with it. But failing to even attempt to make changes we know may help, simply because “we don’t know for certain” is insane!

      We cannot know for certain until long after most actions we can take at reasonable cost will be unavailable to us.

      I expect at least another 90 cm sea level rise by 2027–most of that will occur within the last few months. It could go as high as 5 m…much depends upon Antarctic melt which is propelled by both warm ocean water and subsurface volcanic heating.

      If sea levels rise, would you rather have everyone already moved to safe ground in advance–or try to deal with tens of millions of refugees? Because those are the choices, and right now, people like yourself are prefering to risk the refugee problem to avoid the much less expensive option of preparation. Refugees are thousands of times more expensive than orderly relocation.

      Right now, the USA is preparing for less than the most optimistic predictions of sea level rise–5 feet by 2100 (most optimistic* is 2 m by 2100.)

      I prefer to be ready for disasters BEFORE they are supposed to occur–not afterwards. The costs of preparing are so much lower than the costs of being caught unperpared, and most changes are cost effective in any case!

      E.G. the USA should have a building code requiring buildings to withstand a tornado–since nearly all of the country is subject to tornadic storms; no buildings should be built on flood plains, and existing structures should be removed; no destroyed building should be rebuilt as it was without addressing the issues which caused it to be destroyed (current homeowners insurance usually REQUIRES that the home be rebuild exactly as it was–ensuring that the next time that type of disaster hits, the building will be destroyed again; flood insurance should be prohibited from being used to rebuild on the same site, and no insured should be able to collect more than once–flood insurance was supposed to enable people to move off of the flooding area–not rebuild every few years!

      *most optimistic, outside of those few who believe that there is going to be NO sea level rise.



ImaGeo is a visual blog focusing on the intersection of imagery, imagination and Earth. It focuses on spectacular visuals related to the science of our planet, with an emphasis (although not an exclusive one) on the unfolding Anthropocene Epoch.

About Tom Yulsman

Tom Yulsman is Director of the Center for Environmental Journalism and a Professor of Journalism at the University of Colorado, Boulder. He also continues to work as a science and environmental journalist with more than 30 years of experience producing content for major publications. His work has appeared in the New York Times, Washington Post, Audubon, Climate Central, Columbia Journalism Review, Discover, Nieman Reports, and many other publications. He has held a variety of editorial positions over the years, including a stint as editor-in-chief of Earth magazine. Yulsman has written one book: Origins: the Quest for Our Cosmic Roots, published by the Institute of Physics in 2003.


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