Study: Greenland Ice Sheet was smaller 3000-5000 years ago than today

From the University of Buffalo

Clues in the Arctic fossil record suggest that 3-5,000 years ago, the ice sheet was the smallest it has been in the past 10,000 years

shells in a hand

Shells from Greenland. By dating fossils like these, scientists have come up with a new technique for determining when glaciers were smaller than they are today. Credit: Jason Briner

Summary:

  • Ice sheets are like bulldozers. As they grow, they push rocks, boulders, clams, fossils and other debris into piles called moraines.
  • By dating ancient clams in moraines, scientists have come up with a new technique for determining when glaciers were smaller than they are today.
  • The technique suggests that the Greenland Ice Sheet was at its smallest point in recent history 3-5,000 years ago — information that could improve our understanding of how ice responds to climate change.

BUFFALO, N.Y. — Think Greenland’s ice sheet is small today?

It was smaller — as small as it has ever been in recent history — from 3-5,000 years ago, according to scientists who studied the ice sheet’s history using a new technique they developed for interpreting the Arctic fossil record.

“What’s really interesting about this is that on land, the atmosphere was warmest between 9,000 and 5,000 years ago, maybe as late as 4,000 years ago. The oceans, on the other hand, were warmest between 5-3,000 years ago,” said Jason Briner, PhD, University at Buffalo associate professor of geology, who led the study.

“What it tells us is that the ice sheets might really respond to ocean temperatures,” he said. “It’s a clue to what might happen in the future as the Earth continues to warm.”

The findings appeared online on Nov. 22 in the journal Geology. Briner’s team included Darrell Kaufman, an organic geochemist from Northern Arizona University; Ole Bennike, a clam taxonomist from the Geological Survey of Denmark and Greenland; and Matthew Kosnik, a statistician from Australia’s Macquarie University.

The study is important not only for illuminating the history of Greenland’s ice sheet, but for providing geologists with an important new tool: A method of using Arctic fossils to deduce when glaciers were smaller than they are today.

Scientists have many techniques for figuring out when ice sheets were larger, but few for the opposite scenario.

“Traditional approaches have a difficult time identifying when ice sheets were smaller,” Briner said. “The outcome of our work is that we now have a tool that allows us to see how the ice sheet responded to past times that were as warm or warmer than present — times analogous to today and the near future.”

The technique the scientists developed involves dating fossils in piles of debris found at the edge of glaciers.

To elaborate: Growing ice sheets are like bulldozers, pushing rocks, boulders and other detritus into heaps of rubble called moraines.

Because glaciers only do this plowing when they’re getting bigger, logic dictates that rocks or fossils found in a moraine must have been scooped up at a time when the associated glacier was older and smaller.

So if a moraine contains fossils from 3,000 years ago, that means the glacier was growing — and smaller than it is today — 3,000 years ago.

This is exactly what the scientists saw in Greenland: They looked at 250 ancient clams from moraines in three western regions, and discovered that most of the fossils were between 3-5,000 years old.

The finding suggests that this was the period when the ice sheet’s western extent was at its smallest in recent history, Briner said.

“Because we see the most shells dating to the 5-3000-year period, we think that this is when the most land was ice-free, when large layers of mud and fossils were allowed to accumulate before the glacier came and bulldozed them up,” he said.

Because radiocarbon dating is expensive, Briner and his colleagues found another way to trace the age of their fossils.

Their solution was to look at the structure of amino acids — the building blocks of proteins — in the fossils of ancient clams. Amino acids come in two orientations that are mirror images of each other, known as D and L, and living organisms generally keep their amino acids in an L configuration.

When organisms die, however, the amino acids begin to flip. In dead clams, for example, D forms of aspartic acid start turning to L’s.

Because this shift takes place slowly over time, the ratio of D’s to L’s in a fossil is a giveaway of its age.

Knowing this, Briner’s research team matched D and L ratios in 20 Arctic clamshells to their radiocarbon-dated ages to generate a scale showing which ratios corresponded with which ages.

The researchers then looked at the D and L ratios of aspartic acid in the 250 Greenland clamshells to come up with the fossils’ ages.

Amino acid dating is not new, but applying it to the study of glaciers could help scientists better understand the history of ice — and climate change — on Earth.

The study was funded by the National Geographic Society and U.S. National Science Foundation.

Download High-Res Images:
Two researchers picking fossils out of a large rock-like entity

UB researchers Sam Kelley, left, and Sandra Cronauer pick fossils out of a Greenland moraine — a rock, sediment and shell pile created when a growing glacier bulldozed material in its path into a pile. Such fossils hold clues about the history of the Greenland Ice Sheet, a new study finds. Credit: Jason Briner

icebergs floating on water in front of a steep cliff

View of Upernavik Isfjord, where icebergs pass by on their way from Greenland to the ocean. A new study uses Arctic fossils to illuminate the history of the Greenland Ice Sheet, which drains huge volumes of ice through a few select glaciers that calve into the ocean. Credit: Jason Briner

an expanse of ice meeting water

A calving glacier on western Greenland. Glaciers like this flow on top of ocean mud, which contain fossils, scooping it into piles called moraines that sit at the glacier’s edge. Credit: Jason Brine

a hand holding whitish shells

Shells from Greenland. By dating fossils like these, scientists have come up with a new technique for determining when glaciers were smaller than they are today. Credit: Jason Briner

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83 thoughts on “Study: Greenland Ice Sheet was smaller 3000-5000 years ago than today

  1. It’s refreshing to see real paleoclimate science being practiced.

    Climate scientivists will have a hard time getting rid of the Holocene Optimum.

  2. Good work.
    The climastrophists also have a rough time explaining away the rise and fall of the Maritime Archaic. Mostly it is just ignored, as with most other real findings.

  3. Gee, an article where “this is important towards an understanding of climate change” actually might have some substance.

    But then:
    “It’s a clue to what might happen in the future as the Earth continues to warm.” right back to the old meme, as if ‘warming’ was something unnatural…and there was grant money for the picking.

    Meh.

  4. This is pretty interesting, it shows the effects of lags, it seems to me.

    Our present interglacial, the Holocene, was at its warmest about 8 K to 6 K years ago, and has been cooling since. However, even with the cooling, Greenland apparent continued to lose ice for another few thousand years. That is the lag, just as July and early August are very hot in the northern hemisphere, usually hotter than June 21, even though the summer solstice is June 21.

    Then Greenland started to add ice, the beginning of the long descent into the next ice ago.

    That has now reversed, with Greenland losing tiny amounts of mass, largely due to — got to say it, it is true — greenhouse gas emissions. My sense is that future losses will be quite small, since there was a 6,000 year period during the previous interglacial (the Eemian) when Greenland was about 8 degrees warmer than today, yet only lost about one inch per century (the Dahl Jensen article, from the Bohr institute, reported in WUWT several months ago).

    So acknowledging the role of greenhouse emissions isn’t the same as saying catastrophe will soon happen, or we have to have a large social cost of carbon, it is just saying what is true.

  5. Even though the explanation for the findings are aesthetically apealing, there are always the confounding factors. A long time ago I thought I somewhat understood glaciers after spending a year helping with some measurements of the Greenland ice cap in IGY 1968. After a talk with Roman Motyca, a glacier expert, at the University of Alaska at Fairbanks, I realized I knew nothing. Glaciers have their own internal surge-stick cycles which may be periodic or random from daily to hundreds of years which are also modulated by local and regional climatic conditions. It will require considerable more interference free work to get a hint of what happened and is happening with regards to glaciers and ice caps. The work by this group is a good effort a gathering data.

  6. John says:
    November 22, 2013 at 12:56 pm
    That has now reversed, with Greenland losing tiny amounts of mass, largely due to — got to say it, it is true — greenhouse gas emissions.
    Care to expound on how GGEs are melting the ice? Thought not.

  7. A long time ago something happened that changed the framework within which weather happens. Historically we know this time as the beginning of the Little Ice Age. We don’t know what happened but we know how the weather responded – the Earth endured hundreds of years of cold weather. That event, what ever it was, ended after some unknown period, and the weather responded by returning to approximately what it was prior. We don’t know what the periods were for the initiating event that altered the climate framework or for the response the weather had for that change. We probably have the information carefully collected as to the exact cause but the exact cause has nothing to do with humanity and so offered no path for social engineering and so is ignored. Our go-to climate experts are certifiable morons.

    We should probably start looking for the event that modified the framework and stop looking at the responses (such as receding glaciers, warming, increased CO2, SUVs) as if they were the cause. Knowing this might help us to understand what events cause the framework to change so drastically that we end up in these brief interglacial periods, because this one is going to end some day and no amount of social engineering is going to stop it. Along the way there will be – or at least can be – more events that tweak the climate framework in ways that create climate optimums and little ice ages. The Climate Consensus Age has ended and it’s time move beyond the morons and get back to hard science.

    Australia and Canada have already started the process, and Japan is coming on board. It all starts with how you vote.

  8. Just another reason I roll my eyes every time some “warming-doomster” declares that this or that is “UNPRECEDENTED”

    CRIPES!! It’s all a matter of perspective and time-scale.

    From my geological perspective, it is patently obvious that CO2 is largely immaterial in climate history.

    BTW, just finished “The Chilling Stars” by Svensmark and Calder. Excellent readable summary of evidence for influence of cosmic rays on cloud formation and, thus, climate. Highly recommended!

  9. For goodness sake stop bringing facts into an emotional / religious subject. AGW devotees will see what they want to see and surround themselves with like minded zealots – voila successful groupthink. All the time straining at gnats whilst unseeing of the elephant in the room.

    In Oz we have a wonderful commentator called Gerard Henderson. His weekly epistle “Media Watch Dog” (not to be confused with the ABC’s contortions of the same name) this week expressed it as follows …..

    “This wasn’t news. More like a (secular) Church where preacher Anna Fromberg got the congregation to join in her climate change chorus in a choir where everyone agreed with everyone else.”

  10. During the period of time talked about in the article the northern hemisphere was at the tail end of the hypsithermal interval that lasted for approx. 4 thousand years . This time period was [very] arid and hot and greatly affected the archaic Native American culture.

    [For other readers who don't know your terms, please define hypsithermal. Mod]

  11. Over interpretation of the data is almost a sin. I dont know how they can come to the conclusion that the glaciers were smaller when the mollusks were growing. All it means is that the glaciers were not moving enough to reach the mollusk beds when mollusks were growing in the beds. The reasons for the glaciers not reaching the beds are many. Other data from the area, such as sediments that contain pollen, glacier silt, other life forms, etc, are needed in order to make a more credible fairy tale. The interpretations in my view are always fairy tales. The data, if high quality, may provide valuable insights in the future for other fairy tales that more accurately describe and make sense of reality. Science in my view is always a work in progress.

  12. Gosh, 16 posts and nobody has mentioned the Vikings. Don’t you know it was all green when they were there otherwise why would it be called Greenland /sarc

    The points made by otsar are interesting. If glaciers respond to local climate, then it means that
    (a) you cannot conclude that, if a glacier retreats, it means that it is getting warming.
    but also
    (b) if a glacier retreats and exposes something interesting, then you cannot conclude it was warmer back then.
    In fact, the simple act of retreating or advancing of on glacier shows nothing (presumably if they all do it however that does show something)

  13. As I understand it, sea levels were lower 4000 years ago than they are today.

    If this is so, and if Greenland had less ice, then other locations must have had much more ice. So where was the ice?

  14. Is it possible that whatever was happening in Greenland 3000 – 5000 years ago was a local climate variation and not a global one? Not all climate changes are global, after all. One area can warm while another cools, right?

  15. Because radiocarbon dating is expensive, Briner and his colleagues found another way to trace the age of their fossils.
    Their solution was to look at the structure of amino acids —

    Say what? They didn’t use the generally accepted methodology to date their samples which is inexpensive enough that it appears in hundreds if not thousands of papers? Instead they substituted some other method they call D&L. Ooops, they DID use radiocarbon dating for 20 shells as a calibration for the other 250 shells. So they could afford to mount the expedition, and do radiocarbon dating on 20 shells, and amino acid profiles of 250…. Seriously, they couldn’t just do radiocarbon dating on the other 230, it was THAT much cheaper to count amino acids instead?

    I smell a rat. Or a rotten clam. Well something stinks.

    The vikings apparently found a much smaller ice sheet too, that’s why they settled there a thousand years ago.

  16. rabbit says:
    November 22, 2013 at 2:23 pm

    As I understand it, sea levels were lower 4000 years ago than they are today.

    If this is so, and if Greenland had less ice, then other locations must have had much more ice. So where was the ice?

    I don’t know but were there not whales and walruses in the Great Lakes about then?

  17. last nite, i watched an old bbc horizon docu online about a plane that disappeared in South American Andes in 1947 – no debris found until 1998 when the glacier it got trapped in had shifted to lower, warmer temps & melted:

    Wikipedia: BSAA Star Dust accident
    In the late 1990s, pieces of wreckage from the missing aircraft began to emerge from the glacial ice. It is now assumed that the crew became confused as to their exact location while flying at high altitudes through the (then poorly understood) jet stream. Mistakenly believing they had already cleared the mountain tops, they started their descent when they were in fact still behind cloud-covered peaks, and Star Dust crashed into Mount Tupungato, killing all aboard and burying itself in snow and ice…
    Star Dust is likely to have flown into a nearly vertical snow field near the top of the glacier, causing an avalanche that buried the wreckage within seconds and concealed it from searchers. As the compressed snow turned to ice, the wreckage would have been incorporated into the body of the glacier, with fragments emerging many years later and much farther down the mountain. Between 1998 and 2000, about ten per cent of the wreckage emerged from the glacier, prompting several re-examinations of the accident. More debris is expected to emerge in future, not only as a result of normal glacial motion, but also as the glacier melts….

    http://en.wikipedia.org/wiki/BSAA_Star_Dust_accident

    i found nothing online to suggest any further wreckage has been found since, and it made me wonder if this saga could shed any light, one way or another, on glacial melts & CAGW:

    Unexplained Mystery of the Star Dust Plane Crash (Full BBC Documentary)

  18. This is not a new technique–it’s a standard geologic practice that’s been used for many years. But it’s not quite as simple as implied in the paper. Let’s take a look at the conclusions and see if the evidence supports them.
    1. “scientists who studied the ice sheet’s history using a new technique they developed for interpreting the Arctic fossil record. The study is important not only for illuminating the history of Greenland’s ice sheet, but for providing geologists with an important new tool: A method of using Arctic fossils to deduce when glaciers were smaller than they are today.”
    There is nothing new about this technique—it’s standard geologic practice. Geologists have been doing this for many decades.
    2. “Ice sheets are like bulldozers. As they grow, they push rocks, boulders, clams, fossils and other debris into piles called moraines… When the most land was ice-free, when large layers of mud and fossils were allowed to accumulate before the glacier came and bulldozed them up. Because glaciers only do this plowing when they’re getting bigger, logic dictates that rocks or fossils found in a moraine must have been scooped up at a time when the associated glacier was older and smaller.”
    Lack of basic glaciology and pretty bad logic here. Judging from the photos, the moraine here is a typical push moraine, common to many glaciers that fluctuate slightly. The notion that glaciers only do this plowing when they’re getting bigger is not true. This moraine probably hasn’t been pushed more than a few meters from where the shelly sediment was originally deposited. It certainly wasn’t pushed from any great distance. The glacier doesn’t even have to be growing to plow up a small push moraine like this—this can occur even seasonally—ice can melt back in summer, then advance a few meters in winter, plowing up small moraines in front of it. Thus, all you can surmise from this is that the glacier has plowed up some shelly material a short distance in front of it that had been deposited there a few thousand years ago.

    3. “if a moraine contains fossils from 3,000 years ago, that means the glacier was growing — and smaller than it is today — 3,000 years ago. …. The finding suggests that this was the period when the ice sheet’s western extent was at its smallest in recent history”
    Not necessarily—bad logic here–the glacier could have been larger and/or smaller and may have advanced well beyond this point in the past, riding over the underlying sediment, then retreating to near its present position before the ice advanced a few meters and plowed up the moraine.
    4. “The Greenland Ice Sheet was at its smallest point in recent history 3-5,000 years ago.”
    All this tells you is that when the fossils were deposited, this area was under water and the ice was not grounded. The ice margin may well have been only a few meters upvalley and could have been either smaller or larger since then.
    5. “What’s really interesting about this is that on land, the atmosphere was warmest between 9,000 and 5,000 years ago, maybe as late as 4,000 years ago”
    That’s definitely not true—the Greenland GISP2 ice core records temperatures that were warmest about 7-9,000 years ago (except for the Minoan Warm Period about 3300 years ago). Temperatures remained at least 1°C warmer than present until about 1500 years ago.
    6. Ages were determined by amino acid dating.
    Amino acid dating is much less precise than 14C dating and entails a much higher level of uncertainty because D/L ratios are temperature dependent and establishing the temperature history of a shell is difficult to do. Most geologists consider amino acid dating to give an ‘age estimate,’ rather than a precise date.

    Conclusion: Unfortunately, these data do not support the conclusion that the ice cap was a great deal smaller in the past.

  19. Study: Greenland Ice Sheet was smaller 3000-5000 years ago than today

    So was it bigger during the earlier Mid Holocene Climate Optimum? I gather it was warmer too. Bring out the Hockey Sticks, turn them upside down, it’s worse than we thought! We must act now!

  20. Another interesting factoid.
    As usual, no explanation provided as to WHAT causes the changes in climate that produce ice ages, warming, etc.
    If you cannot EXPLAIN the historical climate, you cannot presume to predict the future climate.
    The inability to EXPLAIN the historical climate is proof positive that the myriad factors that determine the climate are simply unknown as are their interactions.
    Of course, this uncertainty means zero to the scientific community at large as they remain totally silent in the face of the climate science AGW nazis within their community.
    Oh, how Lysenko must be turning in his grave wondering why he lived 60 years too soon.

  21. 3-5,000 years ago, the ice sheet was the smallest it has been in the past 10,000 years“.
    Hmmm. It must have been warmer then. Check —

    — Well, 3-3,5000 years ago saw the warmest Greenland temperatures of the last 6,000 years. And they are talking about ice sheet size not temperature. Not a perfect fit, but methinks they are on the right track. [NB. Either set of data could be out, I'm not calling one right and the other wrong].

  22. Being somewhat dense I’m having a problem understanding how ocean water melts land-based glaciers without warming the air surrounding the glaciers first.

  23. Don Easterbrook is right. There is some fundamental glaciology missing here.

    A push moraine in the front, not contaminated by the debris of a terminal moraine? I dunno what debris in it would mean. Obviously a push moraine means that there was nothing after it to destroy it. Or are these overridden moraines? Which would should a previous smaller glacier. I still don’t know what to make of it.

    The 3,000 – 5000 year age is interesting, though. Corresponds to the Dorset people, a pre-Inuit group that were in their final stages when the modern Inuit came east from Siberia/Alaska when the Arctic reopened. There was a warming back then (Minoan Warm Period, roughly).

  24. Thank you Don Easterbrook and Doug Proctor for taking up the geological cudgels. I feel calmer now. I don’t know how these Buffalos expect their findings and conclusions to be taken seriously when they embed them in such outrageous geology.

  25. Don Easterbrook says:
    “the Greenland GISP2 ice core records temperatures that were warmest about 7-9,000 years ago (except for the Minoan Warm Period about 3300 years ago).”

    That warm spike in Greenland 1300-1200 BC was definitely very a cold period for the temperate zone, and was the century of the demise of the Minoans, it was all over by 1200 BC, as it was for other cultures.

  26. Before the HockeyStick it was generally accepted that Scandinavia 8000-2500years ago was 2-4 degrees varmer than “today”, say 1900. Mostly based on archeological indices like trees growing 400m higher up in the mountains, elm and oak growing much further norh, boars and deer living further North etc.
    That the Greenland glaciers had a minima in the same period makes good sense since we are at about the same lattitude. As long as you stress this was a local and/or very short phenomenon,and bend your knees to AGW this may pass peer review.

  27. A month ago mosses from Baffin Island were telling us that our climate is now the warmest in 120,000 years:

    http://wattsupwiththat.com/2013/10/24/claim-last-100-years-may-be-warmest-in-120000-years-in-the-arctic-but-not-so-fast/

    Now Greenland moraines have spoken up and claim that that island was quite a bit warmer about 5,000 years ago. OK, they’re two different locations, but they’re in the same neighborhood. It’s hard to believe that there could be an extended, glacier-melting warm period at one location not having spillover effects at the other. There’s a long way to go before we have a comprehensive climate history of the Arctic.

  28. Mike Bromley, you point out the Get Out of Denial Jail Free card these author used.

    It is obvious to all non-doctrinaires that if it was warmer, and there was less ice in Greenland, 3000 – 5000 years ago, clearly there was not a problem then, so why would it be a problem now?

  29. I too, as a geologist, do not see the derived logic as being correct within this paper. There are just too many possible variables, e.g. as mentioned by Don Easterbrook. In essence, a glacier, shrinks and grows according to many climatic changes and their causes. From season to decadal, centennial, etc – it seems illogical to deduce that deposits within terminal morraines are of a certain age UNLESS you know that the glacier has been constant in its advance (or retreat) – up until such advance (or retreat) changed AND it was subsequently not surpassed. Given that we have seen fairly significant ice melt/changes in our recent ‘records’ it does not follow that assumptions of continuous advance of past glaciers is a reasonable deduction. Indeed, one might even say that glacial morraines (especially palaeo ones) are to all intent, useless in providing much information at all!
    Add to this the fact that glaciers can ‘hold’ their ‘pickings’ for quite some time before deposition – or indeed, over time a series of different periods of picking-up and re-deposition (which obviously requires ice advance and retreat) – it seems that any collection of material is likely to be highly mixed, and thus of essentially indeterminate ‘origin’ with respect to age of plucking and/or deposition.
    My thoughts are this is extrapolation taken to a significant extreme.

  30. Okay – climate fluctuates due to natural causes. Perhaps I’m the one that isn’t getting this – I swear this planet had multiple ice ages and interglacial warm periods in between. Here in Canada we have a Canada because that two mile thick sheet of ice covering this country of melted – which none of the AGW crowd knows how to answer when I ask what melted that ice? Moreover, CO2 on the historic earth was all over the darn place whether or not it was warm or ice. That ice does expand and recede something new to them?

  31. The total sea ice anomaly will have to be announced as positive for the 2013 year soon.
    Could Anthony or Werner put up a countdown clock on this for the remaining month or do an article on this as positive news over the next 3 colder years needs to be pushed into the mainstream.
    Also does anyone know how many years/centuries ago sea ice extended from Greenland to Iceland?

  32. I wonder what the cover of National Geographic might have looked like 3,000 years ago – horror tales of burial under hundreds of meters of ice caused by man-made global cooling? Liberty Island high and dry in an empty New York harbor? Hiking trails to Staten Island? No hyperbole is unfit to land on the NG cover page.

  33. Kev-in-UK: “it seems that any collection of material is likely to be highly mixed, and thus of essentially indeterminate ‘origin’ with respect to age of plucking and/or deposition.”

    This is my sense of it also. But by the same token, if they do receive samples that are at least X old, then it either grew in the ice, or the ice covered ran over the top of it at some point. If we’re not talking about ice-bound fauna, Yeti’s, and other such things, it does require that the given sample site had to be clear at some point in the past long enough for the fauna to grow. Though, as another mentioned, there can be expected variance in things generally. One extent doesn’t define all extents.

  34. “It’s a clue to what might happen in the future IF the Earth continues to warm.” – Fixed it for them :)

  35. Igor Karlic -
    it seems COP19 talks went on til late fri nite & may continue sat. Guardian’s Fiona sees progress:

    23 Nov 03.48 AEST : Guardian: Fiona Harvey: US backs timetable for global climate deal at Warsaw talks
    American envoy throws weight behind timeline for targets in a move that could break deadlock
    Todd Stern: “The new draft [text on this part of the talks] is in our judgment an improvement on the previous one. It still does not do all the things it needs to do: there could be stronger language indication an effective timeline to drive forward, to give greater clarity about what initial commitment should be put forward … so that everyone from the press, thinktanks, civil society can review and analyse the process…
    As the talks looked set to continue into the night, many participants were saying that some progress had been made…

    http://www.theguardian.com/environment/2013/nov/22/us-timetable-global-climate-deal-warsaw-talks

    3 hours later, Fiona sees failure:

    23 Nov 06.58 AEST: Guardian: Fiona Harvey: Warsaw climate change talks falter as EU and developing countries clash
    EU chief chastised for expressing frustration with failure to agree timetable on emission cuts and attempts by some to opt out
    United Nations talks on climate change were on the brink of breaking down on Friday as a group of developing countries launched a furious attack on the European Union over plans to set out a timetable towards a global deal on greenhouse gas emissions…
    In a dramatic intervention late on Friday, Venezuela’s head of delegation, representing a group of “like-minded countries” including China, India, Saudi Arabia and Malaysia, accused the EU of “damaging seriously the atmosphere of confidence and trust in this process”. Claudia Salerno said: “We are shocked by the brazen attack against our group by Hedegaard – it is incredible that she has chosen to accuse our group of blocking progress.”…

    http://www.theguardian.com/environment/2013/nov/22/warsaw-climate-change-talks-emissions-cut-timetable-eu

  36. I can only assume that glaciers grow from the top. When they shrink they can melt and sublimate into the air (warmer air temps) or they can melt into the ocean. If the latter you can have warmer water and/or higher water levels. For any appreciable melt there would have to be significant sea level rise. No? So how do you raise the water levels significantly without raising air temperature (leading or lagging)?

  37. in the article body:

    ‘When organisms die, however, the amino acids begin to flip. In dead clams, for example, D forms of aspartic acid start turning to L’s.’

    You mean when claims die, the natural L-forms begin to racemize, i. e., some fraction turns into D-forms?

  38. Study: Greenland Ice Sheet was smaller 3000-5000 years ago than today

    If not then, when will the Holocene Climate Optimum be reached?

    And why.

    Meaning you must also address end MIS-5, MIS-7, MIS-9 and MIS-11 within the concept of why whatever climate is to be certifiably ‘anomalous’.

  39. “logic dictates that rocks or fossils found in a moraine must have been scooped up at a time when the associated glacier was older and smaller.”
    ============
    Logic and dictates don’t impress me, it is when logic fails that we learn new lessons.

  40. “Climate scientivists will have a hard time getting rid of the Holocene Optimum.”

    But they aren’t. There is a wealth of studies on conditions suggesting warmer temperatures at locations in the northern hemisphere, where insolation was greater thousands of years ago. The mistake is to pitch these as global phenomena when they are local/hemispheric. What percentage of the planet’s surface is Greenland?

    Eg, here’s a comment in a post at RealClimate pointing out warmer temps in Greenland before 4000 years ago:

    “…during the mid Holocene “climatic optimum”… it was on average much warmer than present in Greenland in summer, due to the peak in Northern Hemisphere insolation due to changes in the earth’s orbit (Milankovitch forcing).”

    http://www.realclimate.org/index.php/archives/2013/01/the-greenland-melt/

    The article also points out that Greenland temps were even warmer during the Emian period. This might come as a shock “admission” to some critics of the mainstream, but it’s actually what they’ve always said. These things are often distorted in the climate debates. In reality, the findings of this new paper is no big challenge to what is understood of NH climate variation in the mid-Holocene.

    When speaking of what has been described as “unprecedented”, a link to an actual quote would put to bed plenty of myths about what the mainstream is saying. They’ve never said this is the warmest the earth has ever been, or that this is the warmest Greenland has been, or that this is the least ice sheet cover Greenland has ever had. Often “unprecedented” refers to the rate, not the degree of change. In any case, sober reading is better than caustic and uncritical commentary.

  41. it’s over:
    23 Nov: Reuters: U.N. climate talks blocked over aid, steps to 2015 deal
    By Alister Doyle and Michael Szabo
    Almost 200 nations were deadlocked on Saturday over how to step up aid to ease the impact of global warming on developing nations as part of the foundations of an elusive U.N. climate accord due in 2015.
    The Warsaw meeting, which had been due to end on Friday but extended into Saturday morning, had little to show after two weeks except for a deal on new rules to protect tropical forests, which soak up carbon dioxide as they grow…
    A draft text merely urged developed nations, which have been more focused on spurring economic growth than on fixing climate change, to set “increasing levels” of aid…
    A text on Saturday said that all nations should submit “intended nationally determined commitments” by the end of the first quarter of 2015, if they could***…

    http://www.reuters.com/article/2013/11/23/us-climate-talks-idUSBRE9AL0J320131123

  42. “What it tells us is that the ice sheets might really respond to ocean temperatures,” he said. “It’s a clue to what might happen in the future as the Earth continues to warm to be visited by UFOs”.

    Fixed.

  43. To put Glaciers into context readers might like to revisit Figure 5 of my recent article which shows glaciers/CET and the hockey stick

    Closed blue line at top means glaciers in retreat.

    This represents NH glacier movement over the last 3000 years. It can not be 100% accurate but the generality should be reasonable as it is derived from hundreds of observations and papers. It should be noted the LIA re-glaciation was the largest in the Holocene . Prior to that the glaciers had been generally diminishing following the last Ice age.

    This means that following this ‘top up’ there is now more snow/ice left to melt again, so presumably that will impact on sea levels.

    tonyb

  44. pat says:
    November 22, 2013 at 2:58 pm

    I found nothing online to suggest any further wreckage has been found since, and it made me wonder if this saga could shed any light, one way or another, on glacial melts & CAGW..

    Thanks for all those references pat. Fascinating stuff.

    I don’t think the discovery of the wreckage will shed any light on CAGW but is certainly demonstrated the movement of glaciers and at the time the effects of the jet stream.

    BTW my theory on STENDEC is that the radio operator was suffering from hypoxia. Hypoxia is medically linked with dyslexia and is thought to be one of the causes if babies are oxygen deprived at birth. And it could be a factor with anaemic hypoxia?

    In this case, it would have been caused by altitude hypoxia. I note it was the captain’s first flight in command over the Andes and he was criticised in the accident report for taking the direct route.

    In taking the direct route, 40 minutes before his last transmission he reported climbing to 24,000 ft. This must have been a very high altitude for a Lancastrian and even though the crew and passengers were equipped with oxygen, I can’t imagine the radio operator having a mask strapped around his face all the time.

    “ETA Santiago 1745 hrs, on Descent” or “Descent” would be quite a normal report especially as we know the aircraft had actually started descent.

    The letters S T E N D E C are exactly the same as in D E S C E N T and too much of a coincidence in my mind that this is what the radio op wanted to send but was slightly hypoxic and probably with a bit of apprehension thrown in, therefore sent out S T E N D E C. But I guess we will never know unless his log or something else comes out of the ice.

    Apologies for the digression but I am sure the glacier still has some secrets to reveal.

  45. It’s my recollection that the trees at the bottom of peat bogs in Scotland and Ireland are from forests that went into decline 4/3K years ago, presumably at the same time the ice started to increase?

  46. Latitude says:
    November 22, 2013 at 2:52 pm

    “..as the Earth continues to warm.”

    “idiots”

    True. Climate scientists appear to have a rather weak grasp of the concept of the present tense….
    Either that or they are liars….
    Chris

  47. These fellows did the work you want to do, if you see clam shells in a moraine at the bottom of a glacier. “How old are they?” is one of the first questions you would ask.

    The second question would be, “What species of clam are they?” Some are assuming that they had to live in salt water, and that the sea would have to be higher, however not all clams live in salt water. We have clams in the brooks where I live in the hills of New Hampshire, roughly a thousand feet above sea level. (Not all clams live in mud, either.)

    I enjoy leaping to conclusions as much as the next man, however it is important to put first things first. First you should gather the facts that can be gathered. In terms of conclusions, clam up.

  48. @ Tom Meehan:
    As I understand it, the amino acid change is roughly analogous to Carbon C12/C14 decay. IOW. when the organism is alive the D-L ratio is relatively constant. When the organism dies that ratio changes The difference between the D-L ratio of a living clam and a fossil clam will give anapproximate age of death. C14 dating is much more precise. Correct me if I’m wrong Dr. Easterbrook.

  49. So….Greenland ice was smaller, but the world was OK.
    The list of failed alarmist claims from the AGW promotion industry keeps growing longer and longer.

  50. Some years ago, someone tried to C14 date living clams in Florida. The reported age was over 1,000 years old – for a living specimen! The suspected reason was that some of the carbon came from dissolved limestone over one million years old. The conclusion was that C14 dating of shells in middens could not be used to date the middens.

    So the question is – Did they C14 date living organisms of the same type?

    Since it is paywalled, I can not check.

  51. The comment about a 1,000 year old 14C of a living clam reminded me that other problems with the dating of these shells may exist. Trees and other vegetative organisms that take CO2 directly from the atmosphere give what is called a ‘radiocarbon age’ that is somewhat younger than the true calendar age. This is because 14C is produced in the upper atmosphere by nuclear reactions that depend on the neutron flux, which varies somewhat over time. In order to compare a radiocarbon age with a calendar age, a calculation must be performed to correct for what is called delta 14C (the deviation of 14C ages from calendar years with time). This is routinely done by 14C labs that use a standard calibration curve. Amino acid ages, which use an altogether different technique, do not need such a correction so thus not the same as radiocarbon ages and cannot be directly compared without converting ’14C years’ to ‘calendar years.’ The point here is that unless they the authors did this, their amino acid ages will all be wrong.
    Another problem is related to the dating of marine shells. If you 14C-date a living tree, you will get today’s age (i.e. zero), but if you date a living clam you will get an age of ~400 to 1100 years. The reason for this is that it takes that long for 14C produced in the upper atmosphere to get into sea water where clams use the carbon to make CaCO3 shells. Thus, for all marine shells, you have to correct the measured age by a delta-R factor that you can determine by comparing old marine shells with wood in the same deposit. So the question in this paper is, (1) did the authors convert 14C years to calendar years before they compared their radiocarbon ages to their amino acid age estimates, and (2) did they correct the radiocarbon ages of the marine shells for delta-R (if they didn’t, their ages will be wrong by 800-1000 years). I don’t know whether or not they did any of this.

  52. Jason Briner, PhD

    said. “It’s a clue to what might happen in the future as the Earth continues to warm.

    I don’t think he has any clue that the warm periods in the ice cores around 1000AD, 500AD, 100BC, 1200BC and 2200BC are the coldest periods in the mid latitudes, and that the chronology of the MWP has been completely misplaced by using the Arctic as a direct measure for the rest of the northern hemisphere. http://snag.gy/BztF1.jpg

  53. John says:
    November 22, 2013 at 12:56 pm
    ………..
    That has now reversed, with Greenland losing tiny amounts of mass, largely due to — got to say it, it is true — greenhouse gas emissions……

    Can you explain the “largely due”? What was the following “largely due to”?
    Here are papers (abstracts) showing higher rates of warming and glacial retreat in the first half of the 20th century.

  54. These glacial expansions, beginning some 3 to 5000 years ago, fit in beautifully with the cooling shown in the Marcott paper from last spring.

  55. Talking of retreating glaciers an ancient forest with tree stumps is being revealed by a retreating Alaskan glacier. I wonder how far north that forest ends.

    An ancient forest has thawed from under a melting glacier in Alaska and is now exposed to the world for the first time in more than 1,000 years.

    Stumps and logs have been popping out from under southern Alaska’s Mendenhall Glacier — a 36.8-square-mile (95.3 square kilometers) river of ice flowing into a lake near Juneau — for nearly the past 50 years. However, just within the past year or so, researchers based at the University of Alaska Southeast in Juneau have noticed considerably more trees popping up, many in their original upright position and some still bearing roots and even a bit of bark, the Juneau Empire first reported last week………

    http://www.livescience.com/39819-ancient-forest-thaws.html

    The Medieval Warm Period was a local affair somehow.

  56. @Don Easterbrook 7:47 am

    Yours are all good points, but I’ll cut the researchers some slack on 14C dating. I really cannot imagine any 14C laboratory that does not convert 14C years to calibrated Calendar years. Yes, we should see the data, but the authors should lose their library cards if they didn’t do that.

    As for the necessary lag between arboreal 14C-years-to-calendar years and marine(shallow) 14C-years-to-calendar years, I confess I had not considered that issue before. But it is not like these clams are the first to visit a 14C dating lab. People have measured marine muds for decades. This must be old hat to 14C dating analysts.

    What is ostensibly new here is the use of a less-expensive D&L amino acid ratio to act as a calibrated proxy to 14C-calendar dating, be it clams or trees. I would REALLY LIKE to see that calibration plot. What is it’s scatter? What is the spread of one clam’s D&L ratio sampled from several spots on one shell? Given a single measured D&L ratio, what is the range of possible 14-C calendar years that result from the calibration? Now convolve those measurement & calibration uncertainties and you have a conservative measurement for the dating uncertainty of the moraine.

    When I first read the D&L ratio measurement in the head post, my first reaction was, “You cannot tell me that the rate of L to D conversion is independent of temperature!. I refuse to believe that. Maybe at sub freezing temps the conversion rate is stady and known. But we are dealing with exposed fossils on solar-heated moraines. I want to see that D&L ratios are not subject to freeze-thaw cycles. Microscopic ice crystals are glaciers of their own pushing around other molecules.

    I’ll accept that D&L ratios might be a useful, locally calibrated relationship. 20 calibrations from one geographic spot might be enough to establish a useful precision. But one location is too aerially restrictive to make statements about overall climate. If you use 20 calibrations over a as few as 5 geologic sites, I have to wonder whether it is a calibration of conflated factors, having less to do with time and more to do with clam fossils sunbathing on multiple episodes of push moraines.

    Healthy skepticism. Let’s see the scatter plots.

  57. Can you explain the “largely due”? What was the following “largely due to”?
    Here are papers (abstracts) showing higher rates of warming and glacial retreat in the first half of the 20th century.

    I followed the links and then later cites to those papers, and the general consensus appears to be that the anomalous warmth and fast-paced retreat of Greenland glaciers in the 20s and 30s was due to low volcanic activity. Most found (those that commented) that there was not yet anough data to ascertain purely from changes in Greenland ice sheet mass balance, whether recent causes are to do with greenhouse gases. All those papers stopped short of making a formal assessment of forcings/natural varibility causes, noting only that current variability was similar in duration and magnitude to earlier anomalies.

    Some of the papers posted in that link were not as described by the commenter. Eg (second paper, Anders, A, Bjork et al on South Greenland ice sheets),

    “We show that many land-terminating glaciers underwent a more rapid retreat in the 1930s than in the 2000s,..”

    was the ellision from the commenter, but the full sentence reads;

    “We show that many land-terminating glaciers underwent a more rapid retreat in the 1930s than in the 2000s, whereas marine-terminating glaciers retreated more rapidly during the recent warming.”

    further into the paper:

    “The retreat in the 2000s is more uniform with only 5% of the 132 glaciers advancing. The highest retreat rates observed in the study occurred in this latest period.”

    and in the conclusions:

    “Although research shows a less pronounced retreat north of the study area, the recent record-setting high temperatures have resulted in an unprecedented extent of glacial retreat in southeast Greenland…”

    Full paper: http://nyheder.ku.dk/alle_nyheder/2012/2012.5/gletsjere_gronland_klimaforandringer/ngeo1481.pdf

    Always best to check sources properly.

    Strangely, one paper cited was written in 1946. How could that be a useful resource to compare recent changes?

    Despite the dubious ellisions and bizzarre choice of the 1946 paper, the recent pace of glacier retreat and warming in Greenland is not much different from previous decadal episodes. More information is needed to corroborate a claim of CO2-induced climate change in Greenland.

  58. Forgot to mention that Greenland climate appears to be strongly tied to NAO fluctuations, as well as volcanic activity. These factors should form part of any attribution study.

  59. The wikipedia entry for Elsmere Island says that it was first settled by people ~4,000 years ago. Must have been a bit more hospitable with less ice and warmer temps. Fits nicely with the Greenland study.

  60. Ötzi the Iceman, believed to have died around 3,300 BCE. Found in a depression among rocks high in the Alps. Being in that dip protected the body from being ground up or moved as the glacier moved.

    Amongst all the other things Ötzi caused to be re-evaluated his existence proved the location he was found was free of ice when he died – but you won’t hear the warmistas acknowledging that fact.

    I figure the reason he was hunted and killed (shot from behind with an arrow), was he was caught with some village headman’s daughter, or wife. ;-)

  61. Great Work! very interesting piece of literature but I am still baffled by all the studies that presume The Earth is in a Global Warming Trend. I agree all people have to do what is prudent to lessen the amount of pollutants being pumped into the air but to say man has a power to change the way Mother Earth repairs and cleans its self I don’t think Man has any power on that part no more than man having any effect on a Giant Typhoon like we just had here in the Philippines and other major catastrophes that happen every year all over the World. Winters are still cold and colder than other years, Some Summers are hotter than others as well. I think if we all do our part to maintain Nature by replacing what we take from it like planting new trees where clear cutting has occurred since trees are a major contributor to cleaning the air. Of course, change the ways we make electricity, stop using coal but find away to use nuclear fuel or hydrogen fuel in cars and stop using fossilized fuels. Oil/Gasoline/ A worldwide addiction we cant seem to change It can be changed and it must if we are serious about the so called global warming. Well that is my rudimentary input on this subject. Thanks For Sharing its entertaining to read all the comments.
    Cary’s Go Green Products & Solutions https://www.facebook.com/groups/253395211475338/

  62. King of Cool -

    thanx for your comments on the docu. as a complete layperson, it struck me as interesting that the glacier hadn’t melted in all those decades UNTIL it reached higher temps at lower levels; of course, maybe it had melted & re-melted, without anyone noticing more debris being temporarily exposed, but pre-Climategate, i was under the MSM impression that the glaciers in South America had all melted (i am exaggerating – LOL), but u know what i mean.

  63. Study: Greenland Ice Sheet was smaller 3000-5000 years ago than today

    Well DUH, the SUV’s were much bigger and les fuel effeicient back then. You guys are really slow sometimes

  64. rabbit says:
    November 22, 2013 at 2:23 pm

    As I understand it, sea levels were lower 4000 years ago than they are today.
    ###

    Your understanding is flawed. Sea levels where quite a bit higher.

    … BURP

  65. Gregg Eshelman says:
    November 24, 2013 at 8:58 pm

    Ötzi the Iceman, believed to have died around 3,300 BCE. Found in a depression among rocks high in the Alps. Being in that dip protected the body from being ground up or moved as the glacier moved.

    Amongst all the other things Ötzi caused to be re-evaluated his existence proved the location he was found was free of ice when he died – but you won’t hear the warmistas acknowledging that fact.

    I figure the reason he was hunted and killed (shot from behind with an arrow), was he was caught with some village headman’s daughter, or wife. ;-)
    ###

    Considering the nature of the artifacts associated with the site, a hunting accident is more probable, but far less headline grabbing.

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