Studies worry: Is Greenland on thin ice?

How much of Greenland's ice melted during past periods of global warming? Two first-of-their-kind studies in Nature look much deeper into the history of Greenland than previous techniques allowed. One of the studies, led by University of Vermont geologist Paul Bierman, concludes that East Greenland -- like the coastal scene shown in this image from near Tasiilaq -- has been actively scoured by glacial ice for much of the last 7.5 million years. The other study presents contrasting results suggesting the disappearance of the ice sheet over the center of Greenland during at least some of the Pleistocene. The two studies improve our understand of Greenland's deep past, while raising questions about both the past and future of its giant ice sheet in a changing climate. CREDIT Joshua Brown/UVM

How much of Greenland’s ice melted during past periods of global warming? Two first-of-their-kind studies in Nature look much deeper into the history of Greenland than previous techniques allowed. One of the studies, led by University of Vermont geologist Paul Bierman, concludes that East Greenland — like the coastal scene shown in this image from near Tasiilaq — has been actively scoured by glacial ice for much of the last 7.5 million years. The other study presents contrasting results suggesting the disappearance of the ice sheet over the center of Greenland during at least some of the Pleistocene. The two studies improve our understand of Greenland’s deep past, while raising questions about both the past and future of its giant ice sheet in a changing climate. CREDIT Joshua Brown/UVM

From the UNIVERSITY OF VERMONT

Greenland on thin ice?

Two studies in Nature open deep history of Greenland’s ice sheet — and raise new questions about its stability

The ice sheet covering Greenland is four times bigger than California — and holds enough water to raise global sea-level more than twenty feet if most of it were to melt. Today, sea levels are rising and the melting of Greenland is a major contributor. Understanding how fast this melting might proceed is a pressing question for policymakers and coastal communities.

To make predictions about the future of the ice sheet, scientists have tried to understand its past, hoping to glean what the ice was doing millions of years ago when the Earth was three or more degrees Fahrenheit warmer than it is now. But our understanding of the ice sheet’s complex behavior before about 125,000 years ago has been fragmentary at best.

Now, two first-of-their-kind studies provide new insight into the deep history of the Greenland Ice Sheet, looking back millions of years farther than previous techniques allowed. However, the two studies present some strongly contrasting evidence about how Greenland’s ice sheet may have responded to past climate change–bringing new urgency to the need to understand if and how the giant ice sheet might dramatically accelerate its melt-off in the near future.

The two new studies were published in the journal Nature on December 8, including one led by University of Vermont geologist Paul Bierman.

In the Video: Paul Bierman, a geologist at the University of Vermont and his colleagues –f rom UVM, Boston College, Lawrence Livermore Laboratory, and Imperial College London–wanted to develop a better understanding of the ancient history of the huge ice sheet that covers Greenland, like this portion of the ice sheet shown from a helicopter on a Bierman-led expedition there. The team studied deep cores of ocean-bottom mud containing bits of bedrock that eroded off of the east side of Greenland. Their results show that East Greenland has been actively scoured by glacial ice for much of the last 7.5 million years–and indicate that the ice sheet on the eastern flank of the island has not completely melted for long, if at all, in the past several million years. Their field-based data also suggest that during major climate cool-downs in the past several million years, the ice sheet expanded into previously ice-free areas, “showing that the ice sheet in East Greenland responds to and tracks global climate change,” Bierman says. “The melting we are seeing today may be out of the bounds of how the Greenland ice sheet has behaved for many millions of years.” CREDIT Joshua Brown/UVM

ICE ON THE EAST

Bierman and four colleagues — from UVM, Boston College, Lawrence Livermore Laboratory, and Imperial College London — studied deep cores of ocean-bottom mud containing bits of bedrock that eroded off of the east side of Greenland. Their results show that East Greenland has been actively scoured by glacial ice for much of the last 7.5 million years–and indicate that the ice sheet on this eastern flank of the island has not completely melted for long, if at all, in the past several million years. This result is consistent with existing computer models.

Their field-based data also suggest that during major climate cool-downs in the past several million years, the ice sheet expanded into previously ice-free areas, “showing that the ice sheet in East Greenland responds to and tracks global climate change,” Bierman says. “The melting we are seeing today may be out of the bounds of how the Greenland ice sheet has behaved for many millions of years.”

Since the data the team collected only came from samples off the east side of Greenland, their results don’t provide a definitive picture of the whole Greenland ice sheet. But their research, with support from the National Science Foundation, provides strong evidence that “an ice sheet has been in East Greenland pretty much continuously for seven million years,” says Jeremy Shakun, a geologist at Boston College who co-led the new study. “It’s been bouncing around and dynamic–but it’s been there nearly all the time.”

CONTRASTING RESULTS

The other study in Nature–led by Joerg Schaefer of Lamont-Doherty Earth Observatory and Columbia University, and colleagues — looked at a small sample of bedrock from one location beneath the middle of the existing ice sheet and came to what appears to be a different conclusion: Greenland was nearly ice-free for at least 280,000 years during the middle Pleistocene — about 1.1 million years ago. This possibility is in contrast to existing computer models.

“These results appear to be contradictory — but they may not be,” UVM’s Bierman says. He notes that both studies have “some blurriness,” he says, in what they are able to resolve about short-term changes and the size of the ancient ice sheet. “Their study is a bit like one needle in a haystack,” he says, “and ours is like having the whole haystack, but not being sure how big it is.”

That’s because Schaefer and colleagues’ data comes from a single point in the middle of Greenland, pointing to a range of possible scenarios of what happened in the past, including several that challenge the image of Greenland being continuously covered by an extensive ice sheet during the Pleistocene. In contrast, Bierman and colleagues’ data provides a record of continuous ice sheet activity over eastern Greenland but can’t distinguish whether this was because there was a remnant in East Greenland or whether the ice sheet remained over the whole island, fluctuating in size as the climate warmed and cooled over millions of years.

“It’s quite possible that both of these records are right for different places,” Bierman says. “Both of these studies apply a similar innovative technique and let us look much farther into the past than we have been able to before.”

NEW METHOD

Both teams of scientists used, “a powerful new tool for Earth scientists,” says Dylan Rood, a scientist at Imperial College London and a co-author on the Bierman-led study: isotopes within grains of quartz, produced when bedrock is bombarded by cosmic rays from space. The isotopes come into being when rock is at or near Earth’s surface — but not when it’s buried under an overlying ice sheet. By looking at the ratio of two of these cosmic-ray-made elements — aluminum-26 and beryllium-10 caught in crystals of quartz, and measured in an accelerator mass spectrometer — the scientists were able to calculate how long the rocks in their samples had been exposed to the sky versus covered by ice.

This isotope technique has been used for several decades for measuring land-based erosion, but this is its first application to ocean core samples, said Lee Corbett, a postdoctoral researcher at UVM and co-author with Bierman. “This has never been attempted with marine sediments,” she says. Their results overcome a basic problem of trying to discern the deep history of ice from bedrock: every time an ice sheet retreats and then grows back, it scours away the bedrock and the isotope record of its own past. “It’s hard to discern an ice sheet’s cycles on land because it destroys the evidence,” she says, “but it dumps that evidence in the oceans, archived in layers on the bottom.”

Now Corbett, Shakun, and others are applying this isotope technique to additional cores taken from around the coast of Greenland to get a more complete and in-focus picture of the whole ice sheet’s long history. And they have already applied the new isotope technique far beyond Greenland–particularly in exploring the much larger, more mysterious ice sheets covering Antarctica.

“These two apparently conflicting — but not necessarily conflicting — studies in Nature really force the issue that we don’t know enough about how ice sheets work over deep time,” Bierman says. “We must recognize the importance of advancing polar science to understand how our world works. And, right now, because we’re pumping huge plumes of greenhouse gases into the atmosphere, we really need to know how our world works.”

The dynamics of Antarctica’s giant ice sheet is full of questions and the disastrous potential. “But there’s enough sea-level rise tied-up in Greenland alone to put a lot of cities and long stretches of coastline underwater,” says Paul Bierman, “including Donald Trump’s property in Florida.”

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161 thoughts on “Studies worry: Is Greenland on thin ice?

  1. Obviously, Anthony, these studies are wrong. There were never any past periods of global warming. These people must be deniers!

    • I have a house near the Sierra . I should move it to the higher end of the lot.

      Well they moved the Temples of Abu Simbel up more than 20 feet. Moving my house should be a snap.

      g

      • Oh I see that they have that old climateering bugaboo.

        Remember that famous ” Far Side” comic panel. The gal with the big hairdo is on the phone in her front living room, talking to her neighbor across the street: ” Hey Mabel, take a look out your front window and describe that thing that is on my front lawn ! ”

        Reason for Flo’s concern is her whole living room front window is blocked out by this one huge eye pressed up against it !

        Basic failure mode of sampled data systems. Simply ignore the Nyquist Criterion.

        Our ice-capaders found themselves another Yamal Christmas tree.

        Well yes of course they want some more grant money so they can go bore some more holes somewhere else.

        G

      • And for Piper Paul’s and Anthony’s benefit, I should tell you that it is strictly forbidden to post ANY Larsen Far Side images any place for any reason.

        A) they won’t grant permission to use them for even the purpose I described.

        So Anthony I recommend that you erase that panel.

        For the record, I have a very nice Black and White print of that panel, stashed away somewhere. I paid $75 for the privilege of having a copy. You can’t buy color prints; only B&W.

        They have a team who do nothing but protect the Larsen copyrights. So I suggest we don’t abuse them.

        But PP got it right. And I see my short term memory of the punch line is like climate anomalies; recently adjusted from the original.

        I bought the panel to show persons how Nyquist failure causes trouble. But I can’t legally use it even in a scientific presentation slide show.

        Its the ultimate in Yamal Charlie Brown Christmas trees.

        But please erase.

        G

    • They have two opposing studies full of “maybe/couldbe” claims that contradict each other and explain this as “fuzziness”.

      When results are so “fuzzy” that opposing conclusion are both within the range of mutual fuzziness, neither study is of use in providing any understanding of the past, let alone the future.

      Sorry, this is not science and such uncertain results should not even be publishable. This is not even a negative result, which would be scientifically valid and useful, they are both non-results.

      • “They have two opposing studies full of “maybe/couldbe” claims that contradict each other and explain this as “fuzziness”.”

        I’m not really sure what the problem is with this. They’re different teams studying different areas with different approaches.

        “When results are so “fuzzy” that opposing conclusion are both within the range of mutual fuzziness, neither study is of use in providing any understanding of the past, let alone the future.”

        How do you know that neither of them are useful until they explore the reasons for the APPARENT discrepancies? This is how science works. Part of the process is understanding what processes to use and how to implement them, and they don’t always know that until they try them.

        “Sorry, this is not science . . .”

        Sorry, but it is.

        “. . . and such uncertain results should not even be publishable.”

        Who should prevent them from being published? Gatekeepers of some sort? Or should they instead publish their uncertain results so other scientists can review their methods and figure out how they can be adjusted to reach more certain results? Kind of like how climate modelers should publish their code so other scientists can understand why their models always fail.

        “This is not even a negative result, which would be scientifically valid and useful, they are both non-results.”

        Welcome to the non-binary world of science.

      • Greg on December 9, 2016 at 3:15 am

        That stuff remembers me words like “I have a degree in applied physics” I read somewhere a while ago.

        And BTW, thanks to Ditzkrieg for a perfect answer to such arrogant “thoughts”.

    • Whenever I read a comment like “and holds enough water to raise global sea-level more than twenty feet if most of it were to melt” I begin to calculate the sanity of the statement. As I’ve frequently said “Any fool can calculate a number, but it takes an engineer to tell you just how big a sh*t load that really is.”
      By my estimates the entire body of Greenland would need to be covered by almost 1 mile deep in ice to provide enough water to cover the present surface of the earth with 20 more feet of sea level, and that does not account for the volumetric consideration of expansion over existing land masses.
      The earth is pretty big and the oceans cover most of it.
      I might expect that if the ice were disappear that Greenland would start bobbing up after being held down under all that oppressive weight, much like much of Scandinavia is doing presently.

      • ???

        the entire body of Greenland would need to be covered by almost 1 mile deep in ice

        Actually, I think that is just about the size of it. Typical thickness is 1.2 – 1.9 miles.

        if the ice were disappear that Greenland would start bobbing up

        Of course, you would expect glacial rebound. As an aside, for people in the US, a great place to see glacial rebound is Acadia National Park in Maine. Walking paths take you along ancient shorelines at the base of cliffs high above the present shoreline.

        All things considered, I really do not think the ice cap is going to melt any time soon.

      • Not merely the ice sheet 1 mile thick, the entire land mass right down to the coast. I don’t believe the coastal ice sheet rises as a 1 mile high cliff from the ocean. The calving from that would be spectacular!

    • The University of Vermont is a cradle for hopeless retards and sniveling, whining snowflakes. A big chunk of their funding comes from the corporate developers that poison Vermont with industrial wind turbines and useless giant solar arrays. There is no intelligent life at UVM so you can take this “study” and round file it.

  2. Here’s what I got out of it:

    i
    may be out of the bounds
    strong evidence
    pretty much continuously
    nearly all the time.”
    what appears to be
    This possibility
    “These results appear to be
    may not be
    “some blurriness,”
    needle in a haystack,”
    not being sure
    a range of possible scenarios
    can’t distinguish
    “It’s quite possible
    “It’s hard to discern
    “These two apparently conflicting
    we don’t know enough
    “including Donald Trump’s property
    /i

      • Measuring the 26Al/10Be ratio produced by cosmic ray interactions (which because of their different half-lives, changes according to when the nuclides were produced) is an old and developed technique that has been used elsewhere. The data are likely good. The uncertainty lies in what they mean.

      • DonB,

        If the sediments are the result of the ice sheet grinding off the surface of Greenland, I seriously doubt those isotopes have seen a cosmic ray for a long time before they were deposited and thus don’t have much relationship to the age of deposition. Hard to get much gamma ray penetration through half a mile of ice! All the ratios will tell you is when those layers were last ice-free.

      • This makes other climate studies look good by comparison. At least the others don’t extrapolate this much.

    • Please run all future Warmist papers through Steve Case. It’ll save so much time. The shorter his dissection, the more worthy the paper.

    • I think that is reasonable. I am always suspicious of climate research that states something will definitely happen. I think Willis usually calls such people ‘catastrophists’ We can have a good idea with regard to trends, we can also say that if A and B happens, it is likely that the result will be C. If I had not seen the phrases you mention, that would have seriously undermined the validity of the paper in my view.

  3. We are not even close to the Northern Hemisphere temperatures of the 1100-1350s. When Greenland had forests. (It now has a small one)

      • But the big question is, what would it take to melt that much ice during the lifetime of anybody that is alive today?

      • People don’t seem to understand that a rise from -35C to -32C is still far below freezing. I do not concede that such an increase, if it happens, does so because of CO2; but regardless of cause, such a rise does not achieve melt by any stretch of the imagination. What would it take to melt the Greenland ice? I posit a WAG (Wild Ass Guess): 10,000 years at a constant 90 degrees F, which is not possible even in Saudi Arabia, let alone Greenland.

      • So, if this giant melt takes place in the near future, what will happen when all that fresh water hits the oceans? Surely this would affect the heat conveyor system, right?

      • Paul, at the current estimated rate of net ice melt in Greenland, it would take between 100 and 150 centuries to melt it all.

        It doesn’t seem to have been significantly affected by anthropogenic CO2, but even if it were, the anthropogenic spike in CO2 levels will probably last another century or two, at most.

      • The Eemian lasted 5000 years longer than the Holocene has to date, and was hotter, yet the only effect on the GIS was that its Southern Dome lost maybe at most 25% more than it has during the Holocene. So, no worries.

  4. “… there’s enough sea-level rise tied-up in Greenland alone to put a lot of cities and long stretches of coastline underwater,” says Paul Bierman, “including Donald Trump’s property in Florida.

    He’s clearly left the realm of dispassionate science and entered the realm of activism. That’s quite a bad hit to his credibility.

  5. His credibility went out the window with the words “Huge Plumes of greenhouse gasses” , and “Donald Trump”. That’s Activist Hack speak.

      • The science is good, but it is being used to validate, instead of test the current popular theory. That critical approach is what has been falling into disuse since Feynman’s day.

  6. I wish people would understand basic English. It is not four times bigger than California, it is four times as big, or three times bigger

    • It is not four times bigger

      Of course it is. Or, if you agree that “one time bigger” is what you are supposed to say for twice as large, then I’ll just go away. I don’t even speak English as my mother tongue. But the rant you rant is common all around the world, and not really as logical as one might think.

      • I’ll freely admit that English is a living language and that rational logical though seems anathema to many, but simply because others are imprecise and sloppy in their usage is not an excuse for furthering the devolution of intelligence. You should strive to better the world not acquiesce.

      • This is not about being rational, IMO. It’s about if n times x’er means n times as x as, or n+1 times as x as. Interestingly, all practical examples say the first interpretation, if needed to distinguish, is commonly used, and the second interpretation is only used by people who first take the second interpretation and then say it was wrong.

        The issue is somewhat complex and detailed, but I’m still right :) Don’t be too nerdy, that’s the lesson.

        Yeah, I’m a nerd on linguistics and maths.

      • Hugs, your statement: “Of course it is. Or, if you agree that “one time bigger” is what you are supposed to say for twice as large…”

        Why would anyone agree with that???

        What you are supposed say for “twice as large” is … TWICE AS LARGE. (there’s even one less letter as compared to “two times bigger” … why would anybody want to “bigger letters” when they don’t have to?)

    • This brings up the age old question of who’s bigger. Mr bigger or Mr bigger’s baby.

      Mr biggers baby is a little bigger

      • I had an interesting discussion on these pages about the actual number of thermometers in the arctic. My recollection was that there as few as 11 north of 70*. I wonder how many thermometers there are north of 80*

        Forget skeptical. I’m becoming positively cynical about whether there is any scientific basis at all to all of these graphs.

      • Overall the temperatures above the 80th parallel are obviously consistently , and sometimes markedly, above the average. This suggests, and is born out by observation, that there will be substantially less refreeze this year. Summer temps look pretty normal, but less ice frozen mean less ice to melt, even if summer temps remain within the average range.

      • Isn’t the higher temperature in the fall of 2016 connected with the increased precipitation? For snow to fall and ice to accumulate you HAVE to have somewhat higher temperatures, or the air wouldn’t be able to carry moisture. Also there is latent heat bound into this water content which must be released when it snows. Am I correct?

    • Dave N – I had fun guessing what parameters these graphs might be showing. Perhaps you can tell us so I can see if I guessed right. Clicking on the link doesn’t help BTW.

  7. Greenland is losing some ice every year, but the rate is low and apparently very consistent. If it were accelerating, then the rate of sea-level rise would be accelerating, too. It isn’t, as you can see from any of the long-term sea-level records, like this one:

    http://www.sealevel.info/Honolulu.html

    Note that CO2 level has had no apparent effect on the rate of sea-level rise.

    Greenland is losing net ice mass, but not at an accelerating rate. It has probably been losing ice mass since at least the mid-19th century. It is gaining some ice in the interior, through snow deposition, but losing ice slightly more rapidly at the periphery.

    However, the net rate of ice loss is equivalent to just a few inches of sea-level rise per century.

    Some people make the naive assumption that warmer temperatures must cause accelerated ice loss from Greenland and Antarctica. But that is not necessarily so. Decreased polar ice cover (Arctic & Southern Ocean) increases water evaporation from the ocean. That cools the ocean by evaporative heat loss (a negative/stabilizing feedback). It also increases “lake-effect/ocean-effect” snowfall downwind.

    Some of that snow falls on the ice sheets and glaciers, increasing ice accumulation, and offsetting meltwater losses.

    Other snow falls on land, increasing albedo and snowpack, decreasing land temperatures, and prolonging winter (another negative/stabilizing feedback).

    Note that snow accumulation has a large effect on grounded ice mass, which in turn affects sea-level. The magnitude of ice accretion from snowfall on ice sheets was illustrated by the team which salvaged Glacier Girl from under 268 feet(!) of accumulated ice, 50 years after she landed on the Greenland ice sheet.
    http://p38assn.org/glacier-girl-recovery.htm

    • Ice layer growth was nearly two metres per year. Between 1988, when the aircraft were discovered and 1990 when the recovery began, another 4 metres of snow/ice was deposited.
      Greenland’s ice sheet is not going anywhere, not in our lifetime. The only thing which will affect it is if a volcano erupts under the ice where the field from Iceland goes under Greenland. That might get exciting.

      • A suggestion, kendo: put contact info on your blog-stub, so that folks can figure out how to email you, when they need to tell you about things like this.

        However, I do not recommend that you put your email address there as plain, unobfuscated text, because that’s an invitation to spam. There are “bots” which roam the Web constantly, searching for email addresses to add to spammers’ lists.

        I usually post my email address as a .jpg picture (line the end of this email), to slow down the spam harvesters. Another approach is to use little puzzles, like this:

        In the following mangled address substitute a ‘E’ for each ‘G’ and ‘@’ for the asterisk to get my real email address: ncdavg4lifg*gmail.com

    • I checked AR5 chapter 13 to see what the IPCC has to say. It’s very lengthy (80 pages) and not easy reading. I could have it all wrong. But I think it says the estimated rate of Greenland ice melt is probably around 0.2mm (2000 micron) and not increasing. That’s seems to be a bit less than 10% of total sea level rise. They do seem to think that the Greenland ice cap could largely melt over a time period measured in millenia (I think I saw 30% remaining in there somewhere, but maybe I misread). Overall — They seem to think you can plan on retiring to your beach house without worrying much about Greenland. (I’d say storm surge from the next really big storm is a much more immediate danger). OTOH, in a few thousand years that property may well be part of an underwater marine park.

      Seems plausible and not all that scary.

  8. Greenland was abandoned in the late middle ages because it got cold. There were many viking settlements there, in Newfoundland and as far south as New Brunswick. These weren’t just encampments inhabited during summer raids, rather generational permanent settlements.

    The vikings eventually left as the climate shifted cold.

    So this study ignores the volatile temperature history of Greenland. After all, the name Greenland was labeled as such because it was green~1000 years ago.

    • the name Greenland was labeled as such because it was green~1000 years ago

      And how many times-ago was it also ice-free and green?

      If it is settled Science that:

      1. The Greenland Ice Sheet (GIS) is up to 4,688 feet thick with the lowest level dating back to roughly 9704 BC (11,700 BP).
      http://www.gfy.ku.dk/~www-glac/papers/pdfs/219.pdf

      2. The accepted start of the warm Holocene Interglacial Period (HIP) began at 11,700 years BP.

      3. The Late Wisconsin Glacier (LWG) covered much of Long Island with ice up to 3,300 feet thick at 18,000 years BP when it stopped advancing.
      http://en.wikipedia.org/wiki/Long_Island_Sound

      4. Via sea level proxies the LWG started to quickly melt at 21,000 years BP.

      Then would someone please answer my following questions which are:

      1. How thick was the Greenland Ice Sheet (GIS) at 18,000 years BP?

      2. Did the GIS also start quickly melting at 21,000 years BP and then exacerbate its melting at 15,000 years BP?

      3. How much of the current GIS is a remnant of the LWG of 18,000 years BP: all, part, or none of it?

      4. If all or part of the current GIS is a remnant of the LWG then does the lowest level actually date much farther back than the settled Science date of 11,704 BP?

      5. If the settled Science date of 11,704 BP for the lowest level of the GIS is correct then is it a scientific fact that the GIS had also completely melted prior to the accepted start of the HIP and has since reformed to its current 4,688 feet thickness?

      6. If the GIS completed melted prior to 11,704 BP then did the earth experience a much more pronounced period of warming prior to the accepted start of the HIP than it is currently experiencing?

      • Samuel. I think you may have mislaid a zero on the age of the Greenland Ice Sheet. GISP-2 cores reached bedrock about 3km down. They have plausibly well dated layers back to 105,000 years BP. There is some additional older ice below that but it’s mechanically disturbed by sliding over uneven bedrock and hasn’t been dated. http://www.iceandclimate.nbi.ku.dk/research/drill_analysing/history_drilling/central_ice_cores/

        Don’t know enough to comment on your other points.

      • 7. How much energy for what period of time would it take to melt the GIS and raise sea levels 20 ft?

      • Don K – December 9, 2016 at 7:04 am

        Samuel. I think you may have mislaid a zero on the age of the Greenland Ice Sheet. GISP-2 cores reached bedrock about 3km down. They have plausibly well dated layers back to 105,000 years BP.

        Don K, one can only assume that I “mislaid a zero” ……. iffen they accept without question what the per se “ice core experts” claim are “well dated layers” in the GIS.

        Thus said, ….. I will post a “statement of fact” that is the basis of my re-stated questions, for your critique of, ….. to wit:

        Beginning around 21,000 BP and continuing almost unabated until around 8,000 BP, ….. or 13,000 continuous years, …… the earth’s glacial ice was melting at an extremely fast pace, …. geologically speaking, ….. that resulted in a 420+- feet rise in sea levels. (see graph below)

        The above “statement of fact” …… begs for the following questions to be addressed, ….. to wit:

        1. How thick (depth) was Greenland’s (GIS) portion of the Late Wisconsin Glacier (LWG) before the “BIG melt” began at 19,500 years BP? (see graph below)

        2. Did the GIS also start quickly melting at 19,500 years BP ,,,,,, and then exacerbate its melting at 15,000 years BP as per noted by the Meltwater Pulse 1A on the Post-Glacial Sea Level Rise proxy graph?

        3. How much of the current GIS is a remnant of the Late Wisconsin Glacier (circa 85K BP to 11K BP) that began its serious melting at 19,500 years BP, …. all of it, ….. part of it, ….. or none of it?

        4. If the rate of glacial ice and snow-pack summertime “melting” during the aforesaid “13K continuous years” was far greater than the wintertime accumulations of snow-pack and/or ice …… then how is it possible for anyone to accurately date the different ice layers that now comprise the GIS?

        5. If only part of the current GIS is a remnant of the LWG then doesn’t the lowest levels of the GIS actually date much farther back than any settled Science date of pre-8,000 BP?

        6. If the GIS completely melted prior to 11,704 BP. …… then didn’t the earth experience a much more pronounced period of warming prior to the accepted start of the Holocene Interglacial Period than it is currently experiencing herein the Late 20th Century Warming Period?

  9. So the large area study shows nothing to worry about, and the small area with iffy data supports the apocalyptic clap-trap of the climate kooks, so of course that is the study that is touted as important.
    And then of course a gratuitous, fact-free visit to Antarctica to add a frisson of scary cliamte stuff just to top things off.

  10. When faced with contradictory results, choose the one that suggests that climate change is worse. Surely?

  11. That is a Glacier flyover in Greenland ? Wow I didn’t know they had helicopters back a 1000 years ago because looking at that it looks more like Norway , Way too much bare and or forested land. Very poor visual. But that is just my viewpoint, to me that doesn’t look like Greenland at all, Norway/ Iceland maybe. Opinions please?

  12. “The melting we are seeing today may be out of the bounds of how the Greenland ice sheet has behaved for many millions of years.” 

    Or not. It depends on how the ice sheet behaved in the past, doesn’t it!

    And we don’t know how it behaved. That’s pretty obvious isn’t it?

    I am impressed by the atomic technique. Well done. The oldest ice in Greenland is much less than 1m years old. That doesn’t mean it didn’t have glaciers the whole time, at least in places.

    It is interesting to think that Greenland may have been ice free for a quarter of the past million years.

    I agree with the estimate of 20 ft sea level rise.

    120 ft for all ice x 5/30 m cu km = 20 ft

    To generate alarm out of that requires imagining a sudden melt, at ‘ridiculous speed’. It would take many centuries to melt. I am quite sure it will. And we will cope.

    • Indeed. The wriggle word may must always be read as may or may not. At that point without further evidence of which alternative is more likely the speculation must be thrown away. Thrown away that is if you wish to make a scientific statement.

    • The ice age ended 10,000 years ago and the general warming, whatever caused it, will continue, interspersed with periods of cold, for again, unknown reasons.

  13. Here’s what I got out of it

    ” blah,blah,blah…. enough water to raise sea level 20 ft. Blah,blah, out of bounds, never seen before melting, blah, blah, warning you Donald Trump, your property will be under water… “

      • It looses the scare factor if they tell us when. We’re warning you Donald Trump, change you views or else. Of course, the climate scientist Al Gore, Nobel prize winner I might add, bought property just a few feet above sea level years ago now right after his famous speech. It should have been already under water… I wanted to buy the property next to his but I missed out on the cap and trade carbon scam. I wonder what they are trading at now. It was down from $35/ton to $3/ton.. and plenty of fraudulent credits as well….

        I did buy some, as I too thought the climate change agenda would keep steamrollering ahead. I had this deep dark fear of freezing to death, unfounded of course based on climate science that there might be run a way warming any day now.

  14. In the year 982 AD a rather turbulent Viking Erik the Red sailed west and found a green land covered in lush grass which he called ‘Greenland‘. He then began to colonise Greenland. It was then green with grass and virtually no ice. Over next four or five hundred years the colony built up to over 4000 – 5000 people with over 150 farms and was more or less self sustaining. The ice returned at the beginning of the Little Ice Age and the colony then failed. During this period there were no cars, factories, central heating or other significant sources of man made CO2. Mick G

    From: Watts Up With That? To: mickgreenhough@yahoo.co.uk Sent: Friday, 9 December 2016, 2:01 Subject: [New post] Studies worry: Is Greenland on thin ice? #yiv5278942884 a:hover {color:red;}#yiv5278942884 a {text-decoration:none;color:#0088cc;}#yiv5278942884 a.yiv5278942884primaryactionlink:link, #yiv5278942884 a.yiv5278942884primaryactionlink:visited {background-color:#2585B2;color:#fff;}#yiv5278942884 a.yiv5278942884primaryactionlink:hover, #yiv5278942884 a.yiv5278942884primaryactionlink:active {background-color:#11729E;color:#fff;}#yiv5278942884 WordPress.com | Anthony Watts posted: “From the UNIVERSITY OF VERMONTGreenland on thin ice?Two studies in Nature open deep history of Greenland’s ice sheet — and raise new questions about its stabilityThe ice sheet covering Greenland is four times bigger than California — and” | |

    • Those colonies were limited to the shoreline and perhaps a very few miles inland. Doubtless the inland portion was glaciated even then. The main livelihoods then were sheepherding and fishing, so the warm, green coastal edge was quite sufficient. The colonies had to leave when ice closed the harbors year-round.

      • Actually the Norse weren’t that into fishing. They were mainly dairymen. They had sheep, too, but their main industry was milk cows.

      • @ John M. Ware
        December 9, 2016 at 8:16 am: Recent ivory analysis suggests they may have earned a lot from Walrus hunting too. Harbour loss, yes, but may have evacuated then rather than dying out.

  15. Just for the sake of the argument. How much time would it take for Greenland to become completely ice-free?
    How much time would it take until the expected rise of sea-level becomes a real threat for mankind living on the shorelines? I suppose that by then the years will be counted as five-digit numbers, if there is anyone left to count.
    So it is either adaptation – or forget it. I’ll choose the second.

    • You are right; it is an inconceivably long time. The greatest ice loss measurement is 100 cubic kilometers per year. Given the enormous volume of ice, Greenland could lose ice at this rate for 400 years and still have 99% of it’s ice sheet left.

  16. Methinks the uncertainty monster has been gorging itself of random data and has shat a pile in front of some ‘lucky’ scientists who have naturally just had to study the phenomoneon. They obviously got funding so good on them. No need to take any notice though, crap is crap.

  17. Two things.
    First – ice melts if it gets warm , realllllllllllllly .
    Second – good chance I will have waterfront property if it all melts which won’t do the realestate values any harm all .

  18. Surely to melt ice you need more than a few degrees of global warming. Latent heat folks. It takes more energy than we have to actually melt all that stuff.

    • Not relevant. The energy needed to melt the ice is constantly being replaced by the sun.
      What matters is the actual temperature.

  19. I don’t know, from the studies which were measuring similar isotopes, I don’t see a very good correlation in the AL26/Be10 measurements versus the other comparative stats we have like the dO18 isotopes from near-by ocean cores. The AL26/Be10 data appears to have really wide error margins and is not a good indicator.

    I would stick with the dO18 history shown in panel “d” in this large image from one of the studies which is also backed-up by sea level estimates panel “e” (versus their estimates shown in the top 3 panels “a, b, c”)

    .

  20. How is everyone enjoying their cold fusion powered cars?
    Lol.
    I always find it hilarious when people put ANY weight to a few scientists using some new method to come to a conclusion..

    • Please criticize the method itself.
      Not everything new is invalid. If that were the case we’d still by driving horse drawn buggies.

      • “… we’d still by driving horse drawn buggies.”

        Speak for yourself … I would have happily given up my horses, for walking, to save New York (20 feet), London (9 feet), and the rest of the world from the great depths of manure that would have piled up in the streets.

        Damn stubborn manure deniers (like you) would have just kept on letting your horses poop in the streets; not caring that linear extrapolation of the recently measured shit piles would surely lead to Catastrophic Anthropomorphic Gutter Waste that would reach the third story windows (you & your damn greedy capitalist fourth story friends don’t care at all about the rest of us).

        We’re all just very lucky that the urban planners recognized the problem, that we all pooled our resources and sacrificed to come up with a replacement for the horse. (that Ford guy didn’t do it … he didn’t create that business … it was the planners and the government that created the streets and the transportation infrastructure that allowed him to thrive …).

        Also, we all need to thank the guy (I don’t remember his name) who gave us time to solve the problem by creating that shit cap/trade system (the stepping stone to the shit tax) that allowed & encouraged us to transition away from horses. And don’t say the pogo stick subsidies that the shit tax funded were a boondoggle; pogo stick transportation was a great idea that was just ahead of its time … we just needed to wait for the technology to catch up and continue with the tax breaks.

        Anyway … speak for yourself … the pogo stick era only stalled because of naysayers like you.

  21. Bierman says. “The melting we are seeing today may be out of the bounds of how the Greenland ice sheet has behaved for many millions of years.”

    Absolute unmitigated rubbish!

    The northern-most lobe of the Greenland ice cap, the Hans Tausen ice cap, melted away completely down to bedrock during the Holocene Maximum, 8,000 – 6,000 years ago. It has reformed over the past 4,000 – 3,500 years, consistent with the decline in Holocene temperatures up to the present, and is currently about 345 metres thick.

    Given that Hans Tausen is at 82-83 degrees north, and is situated on the closest land mass to the North Pole, it is highly likely that the Arctic Ocean was, at least, seasonally ice free during the Holocene Optimum.

    The Danes and Norwegians have conducted detailed studies of the natural history of the region, so Bierman is wasting his time.

    • The northern-most lobe of the Greenland ice cap, …… melted away completely down to bedrock during the Holocene Maximum, 8,000 – 6,000 years ago.

      YUP, and that is pretty much confirmed by this study, to wit:

      Holocene Treeline History and Climate Change Across Northern Eurasia

      Radiocarbon-dated macrofossils are used to document Holocene treeline history across northern Russia (including Siberia). Boreal forest development in this region commenced by 10,000 yr B.P. Over most of Russia, forest advanced to or near the current arctic coastline between 9000 and 7000 yr B.P. and retreated to its present position by between 4000 and 3000 yr B.P. Forest establishment and retreat was roughly synchronous across most of northern Russia. Treeline advance on the Kola Peninsula, however, appears to have occurred later than in other regions.

      During the period of maximum forest extension, the mean July temperatures along the northern coastline of Russia may have been 2.5° to 7.0°C warmer than modern. The development of forest and expansion of treeline likely reflects a number of complimentary environmental conditions, including heightened summer insolation, the demise of Eurasian ice sheets, reduced sea-ice cover, greater continentality with eustatically lower sea level, and extreme Arctic penetration of warm North Atlantic waters. The late Holocene retreat of Eurasian treeline coincides with declining summer insolation, cooling arctic waters, and neoglaciation.

      Read more @ http://www.sciencedirect.com/science/article/pii/S0033589499921233

    • Well, what was happening in the early Holocene which is not happening now to create warm conditions in that part of the world?

      The orbital effects from the part of the Milankovitch cycle the Earth was then in of course.

      and now we see meting without the additional warming effects from that…

      • We’ll let you know when the world warms up another 5C in order to catch up with the Holocene Optimum.

  22. I see people showing the surface mass balance charts above…

    But the “surface mass balance” technique for assessing the ice sheet refers to the amount of snow and ice that accumulates and melts each year. This only accounts for about two-thirds of the losses from the ice sheet.

    Given that it doesn’t include the remaining third of ice that is lost through calving icebergs and ocean melting, it is usually strongly positive at the end of the year

    Once the rate of calving icebergs and ocean driven melting is factored in, the total mass balance will almost certainly be negative – that is, more ice lost than snowfall gained. Since 2003 the GRACE satellite mission has shown a consistent overall net loss of ice from Greenland each year.

    Greenland is definitely still losing ice.

    The main glacial outflows – ice rivers – have shown accelerating retreat in the last 15 years.

      • “AS usual Griff,you ignore posted evidence from earlier in the thread,”

        Griff always ignores evidence, that’s what he does.

        If he didn’t, he’d never have anything to post.

      • Sunsettommy on December 9, 2016 at 7:44 am

        Well, I’m no warmista and do not appreciate Griff’s attitude very much, but…
        As usual Griff, you ignore posted evidence from earlier in the thread…

        Evidence? Which evidence? What about a look at DMI’s Greenland site…
        http://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/
        … and above all carefully reading everything on it?

        Over the year, it snows more than it melts, but calving of icebergs also adds to the total mass budget of the ice sheet. Satellite observations over the last decade show that the ice sheet is not in balance. The calving loss is greater than the gain from surface mass balance, and Greenland is losing mass at about 200 Gt/yr.

        That’s not much of course: compared with the ice sheet’s volume, like a drop in the bucket. But that in turn isn’t a reason to ignore the fact.

        P.S. I watch this DMI page since longer time. A few years ago, we still could read in the text a “1” where now the “2” stands…

    • Griff,
      Calving icebergs and the resulting melting in the sea are the result of advancing glaciers and glacier advance is fed by snow accumulation at higher elevations. So calving glaciers show the opposite to what you allege.

    • Griff, they are also ignoring the two to three feet of ice that is added every year from snow fall.
      Are you finished embarrasing yourself yet?

      • Indeed.

        Operational History
        On 15 July 1942, due to poor weather and limited visibility, six P-38 fighters of 94th Fighter Squadron/1st FG and two B-17 bombers of a bombardment squadron were forced to return to Greenland en route to the British Isles during Operation Bolero. The aircraft were forced to make emergency landings on the ice field. All the crew members were subsequently rescued. However, Glacier Girl, along with the unit’s five other fighters and the two B-17s, were eventually buried under 268 feet of snow and ice that had built up over the ensuing decades.

        Recovery and Restoration
        Fifty years later, in 1992, the plane was brought to the surface by members of the Greenland Expedition Society after years of searching and excavation. The aircraft was eventually transported to Middlesboro, Kentucky, where it was restored to flying condition. The excavation of Glacier Girl was documented in an episode of The History Channel’s “Mega Movers” series, titled “Extreme Aircraft Recovery”.
        The Lightning returned to the air in October 2002.

        https://en.wikipedia.org/wiki/Glacier_Girl

        http://www.airspacemag.com/history-of-flight/glacier-girl-the-back-story-19218360/

        That’s 268 feet of ice build-up in 50 years.

        Doesn’t look like the Greenland icecap is melting to me.

  23. I wonder how all the holes that have been bored in the Greenland Ice Sheet have affected the its melting. Heisenberg or something like that.

  24. The reason no one should care about all this is that any massive ice melt that might be partially due to CO2 is way, way into the future (Trump won’t have to worry about his coastal real estate,I’m quite sure) , a future in which only the technologically ignorant believe will still be powered by gasoline and coal/natural gas, just due to simple economics : 1) given the cost of batteries were are approaching in the near future, electric automobiles are far simpler machines (and lots more reliable) than anything powered by an internal combustion engine. I’ve been an amateur mechanic for decades and would love to convert my 57 Thunderbird to electic – no transmission to worry about, or exhaust system, or cooling system of fuel system, ot the hundreds of machined arts that make up an engine, or for newer cars, the elaborate and complicated electronic control systems that are used by gas powered vehicles. The ability to refuel at home when used for around town transportation, etc etc. Easier to repair (unless it’s an absurdly complicated Tesla Motors vehicle, that is). With multiple electric propulsion motors, even the unlikely event of a motor going bad won’t leave you stranded. 2) Molten salt nuclear reactors are the future. Peiod. Of that I’m quite certain. Once again, the reason is sheer economics plus all of its other major benefits (using nuclear wastes
    for fuel and eliminating them as any major storage concern), totally safe operations, ability to load follow, no need to shut down for refueling, etc etc etc Peter Thiel is backing Transatomic’s version of this new technology, but it is getting all the competition it can handel from Moltex’s innovative and potentially more cost effective and earlier to market design. Not to mention Terrestrial Energy’s design or the unknown design being pursued by the crash program the Chinese govt is backing.
    Peter Thiel is part of the Trump team. Suspect that the Trump administration will get behind the new technology, unlike the corrupt Obama political machine, which threw hundreds of millions into technologically primitive renewable crap owned by his good buddies and political contributors
    to his Democratic Party.

    • Yep. And if Venus pops out of its orbit and smacks into the Earth, it’ll be really bad for the stock market. The two scenarios are probably about equally likely.

  25. From the U of V article, “Today, sea levels are rising and the melting of Greenland is a major contributor.”

    Surprising the article didn’t mention Al Gores average 5″ rise per year sea rise his documentary is Oscar-winning propaganda “An Inconvenient Truth”. I guess they didn’t want to appear too stupid.

    Sea levels are rising, but minimally at about the same rate as the end of the 19th century. Greenland is potentially a greater contributor due to much of the ice being land based. Their studies may indicate Greenland is a major contributor, however to assert that without proving it, is poisoning the well instead of following the evidence wherever it may lead.

  26. Has anyone looked at the uniqueness of weather patterns around Greenland to explain its ice cap? Weather not climate

    • Greenland was largely ice free during the Pliocene and preceding epochs. There is some evidence of a small ice cap on its southern tip at that time. The research cited here also suggests at least montane glaciers along its east coast even in the late Miocene.

      Its present ice sheet is due to new WX patterns, ie climate, established after the formation of the Isthmus of Panama, which caused more warm water to reach the North Atlantic.

  27. I think the scientific techniques they are developing here are interesting and worth pursuing, but are obviously in a very early stage. The problem is they are prematurely trying to reach conclusions about what their results so far mean and how they apply to global warming — such conclusions are not nearly justified given the “fuzziness”. I suspect they know this but feel they need to do it to get more grant support.

  28. Wow this could be way worse than we thought. Then again aren’t we supposed to get rid of millions of people to save gaia.

  29. And of course, the “time to give me another grant” demand is predictably there:

    ““These two apparently conflicting — but not necessarily conflicting — studies in Nature really force the issue that we don’t know enough about how ice sheets work over deep time,” Bierman says. “We must recognize the importance of advancing polar science to understand how our world works. And, right now, because we’re pumping huge plumes of greenhouse gases into the atmosphere, we really need to know how our world works.””

  30. I’d like to see where the interior site is located.

    The Southern Dome of Greenland probably has melted in the past. The Northern, not so much.

    Also wonder if the East Greenland coastal area surveyed is in the north or south.

  31. Given a few millenia to protect his property from 20 feet of Greenland-induced sea level rise, I think Donald Trump would have ample time to….

    Build a wall.

  32. First they say 1. :

    “To make predictions about the future of the ice sheet, scientists have tried to understand its past, hoping to glean what the ice was doing millions of years ago when the Earth was three or more degrees Fahrenheit warmer than it is now.

    and then they say 2. :

    ““The melting we are seeing today may be out of the bounds of how the Greenland ice sheet has behaved for many millions of years.” CREDIT Joshua Brown/UVM

    So I started wondering how in the world they got from 1. to 2. ??

    And then Samuel C Cogar says:

    Samuel C Cogar @
    December 9, 2016 at 6:07 am says:
    During the period of maximum forest extension, the mean July temperatures along the northern coastline of Russia may have been 2.5° to 7.0°C warmer than modern.

    So, I reckon they got from 1. to 2. by reading their grant application and the requisite alarmism phrases required to meet the wording in the grant application.

    (And yes, I have done government consulting work once upon a long time ago where requisite phrases were a must.)

  33. Interesting studies – devalued by

    “And, right now, because we’re pumping huge plumes of greenhouse gases into the atmosphere, we really need to know how our world works.”

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