Changes in the Greenland Ice Sheet volume lag climate changes, such that today’s climate could still be affecting its size in thousands of years’ time


Peer-Reviewed Publication

PLOS

Fig 1. The model domain of the ice sheet model.
IMAGE: THE LEFT SUBPANEL SHOWS THE ICE THICKNESS USED TO INITIALIZE THE MODEL (SHADING) AND THE CONTEMPORARY COAST LINE (BLACK CONTOUR LINE) WHILE THE RIGHT SUBPANEL DEPICTS THE CORRESPONDING BEDROCK TOPOGRAPHY. THESE DATA ARE DERIVED FROM THE ETOPO1 DATA SET [42]. view more C REDIT: YANG ET AL., 2022, PLOS ONE, CC-BY 4.0 (HTTPS://CREATIVECOMMONS.ORG/LICENSES/BY/4.0/)

Changes in the Greenland Ice Sheet volume lag climate changes, such that today’s climate could still be affecting its size in thousands of years’ time

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Article URL:  https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0259816   

Article Title: Impact of paleoclimate on present and future evolution of the Greenland Ice Sheet

Author Countries: Germany, China, The Netherlands

Funding: This work was supported through a grant (Global sea level change since the Mid Holocene: Background trends and climate-ice sheet feedbacks) from the Deutsche Forschungsgemeinschaft (DFG) as part of the Special Priority Program (SPP)-1889 ‘Regional Sea Level Change and Society’ (SeaLevel). C. Rodehacke has been financed through the German Federal Ministry of Education and Research (Bundesministerium fur Bildung und Forschung: BMBF) project ZUWEISS (grant agreement 01LS1612A) and through the National Centre for Climate Research (NCFK, Nationalt Center for Klimaforskning) provided by the Danish State. H.Y., S.X. and X.L are partly funded by the open fund of State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, CAS (SKLLQG1920). Development of PISM is supported by NASA grant NNX17AG65G and NSF grants PLR-1603799 and PLR-1644277.


DOI

10.1371/journal.pone.0259816 

ARTICLE TITLE

Impact of paleoclimate on present and future evolution of the Greenland Ice Sheet

ARTICLE PUBLICATION DATE

19-Jan-2022

COI STATEMENT

The authors have declared that no competing interests exist.

Here is the abstract of the paper not paywalled:

Using transient climate forcing based on simulations from the Alfred Wegener Institute Earth System Model (AWI-ESM), we simulate the evolution of the Greenland Ice Sheet (GrIS) from the last interglacial (125 ka, kiloyear before present) to 2100 AD with the Parallel Ice Sheet Model (PISM). The impact of paleoclimate, especially Holocene climate, on the present and future evolution of the GrIS is explored. Our simulations of the past show close agreement with reconstructions with respect to the recent timing of the peaks in ice volume and the climate of Greenland. The maximum and minimum ice volume at around 18–17 ka and 6–5 ka lag the respective extremes in climate by several thousand years, implying that the ice volume response of the GrIS strongly lags climatic changes. Given that Greenland’s climate was getting colder from the Holocene Thermal Maximum (i.e., 8 ka) to the Pre-Industrial era, our simulation implies that the GrIS experienced growth from the mid-Holocene to the industrial era. Due to this background trend, the GrIS still gains mass until the second half of the 20th century, even though anthropogenic warming begins around 1850 AD. This is also in agreement with observational evidence showing mass loss of the GrIS does not begin earlier than the late 20th century. Our results highlight that the present evolution of the GrIS is not only controlled by the recent climate changes, but is also affected by paleoclimate, especially the relatively warm Holocene climate. We propose that the GrIS was not in equilibrium throughout the entire Holocene and that the slow response to Holocene climate needs to be represented in ice sheet simulations in order to predict ice mass loss, and therefore sea level rise, accurately.

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Willis Eschenbach(@weschenbach)
Editor
January 20, 2022 6:04 pm

This is hilarious. They are running another Tinkertoy™ climate model, but this time for 120,000 years … right. The models can’t predict next month’s weather but it’s totally accurate for a 120,000 year run.

The madness runs deep …

w.

Izaak Walton
Reply to  Willis Eschenbach
January 20, 2022 6:59 pm

And just how fast do you think the Greenland ice sheet should respond to a changing climate? Given the mass of ice and the very slow rate at which the earth’s crust deforms a response time of a couple of thousand of years is plausible.

Pat from kerbob
Reply to  Izaak Walton
January 20, 2022 7:07 pm

Wow, I don’t think you could possibly miss the point more

Bryan A
Reply to  Pat from kerbob
January 20, 2022 7:25 pm

So it size COULD “still be affected” for 1000 years…
I COULD win the lottery…
Cold Fusion COULD be producing grid scale energy in 10 years…
Steorn COULD create overunity through magnetism…
Griff COULD say something useful…
Katie Johnson COULD sleep with me tonight…

Mr.
Reply to  Bryan A
January 20, 2022 7:34 pm

All possibilities except line 5.

Bryan A
Reply to  Mr.
January 20, 2022 10:01 pm

Now, Now, Now…

Graemethecat
Reply to  Mr.
January 20, 2022 11:48 pm

*Snigger*

MarkW
Reply to  Bryan A
January 21, 2022 9:26 am

I for one have no trouble believing that it could take 1000 years for any temperature change at the top of a miles thick glacier, to reach the bottom of that glacier.

That however does not prove, or even imply, that the model in question is any good.

Rational Db8
Reply to  Bryan A
January 21, 2022 1:08 pm

Funny how they miss the fact that if it takes thousands of years, that means the ice loss occurring now (to whatever extent it’s actually occurring), would be in large part not because of today’s temperatures, but because of temp. changes thousands of years ago! Holocene optimum, Minoan Warm Period, Roman Optimum, Medieval Warm Period – all warmer than present day temps.

Logic and reasoning just isn’t the AGW proponent’s forte!

Rational Db8
Reply to  Rational Db8
January 21, 2022 1:13 pm

Also, if Greenland was gaining ice up until the 20th Century, how is it that receding ice has uncovered evidence of Viking settlements there, trees, and so on?

Kristi Silber
Reply to  Rational Db8
January 21, 2022 11:33 pm

No, you miss the point that although “Greenland’s climate was getting colder from the Holocene Thermal Maximum (i.e., 8 ka) to the Pre-Industrial era,” the ice sheet is now shrinking anyway, supporting AGW theory.

Robert Austin
Reply to  Kristi Silber
January 22, 2022 9:08 am

Kristi,
No, it does not necessarily support AGW “theory”. It is actually the AGW hypothesis. The AGW idea is not even close to “theory” yet.
Basically, the ice caps have been retreating with since the end of the last ice age and it has nothing to do with AGW. And they will continue to shrink in fits and starts until this interglacial period ends. Snow is still accumulating on the heights of the Greenland ice cap (see “Glacier Girl”). Any meagre shrinkage is at the edges of the ice sheet and is minuscule compared to the vast size of the inland sheet. And as was previously noted but obviously not registering on the conscience of the true believer, Viking settlements uncovered by retreating ice.

Rational Db8
Reply to  Kristi Silber
January 22, 2022 11:03 am

On the contrary, Kristi, I didn’t miss that at all. But you’re missing my point entirely. Again, the claim is that Greenland was supposedly gaining ice for the last 8,000 years, right up into the 20th Century.

So, how is the ice shrinking now, but not back then, when clearly it was warmer back then than it is now? After all, the trees and other plants that grew there while the Vikings were there can’t grow there now. Why was the ice supposedly growing during the Viking times, when temperatures were warmer than present day temps?

Or are you saying that ice, at temperatures that keeps it frozen, is magically melted by human CO2? That warmer temperatures don’t melt ice, but grow it, if there’s a tiny bit less CO2 in the air (remember, CO2 is a trace gas, we’re talking ppm here)?

Also, why did the previous Greenland occupants die out long before the Vikings got there (at least on the south end of the island), if it wasn’t because the climate there became too cold for settlements to survive?

Trying to Play Nice
Reply to  Kristi Silber
January 22, 2022 3:20 pm

Kristi, I haven’t seen your name in a while. With comments like this one, I hope it’s a while until the next one.

Clyde Spencer
Reply to  Pat from kerbob
January 20, 2022 8:12 pm

He sees only what he wants to see. The quote is for “thousands of years,” which to me means more than “a couple of thousand years.” If they had meant only a couple, they probably would have said that, as Walton did.

Rational Db8
Reply to  Clyde Spencer
January 21, 2022 1:15 pm

Nothing like ‘scientific research’ which is worded so vague that it leaves everyone trying to guess what they actually mean, right?

Carlo, Monte
Reply to  Pat from kerbob
January 21, 2022 7:38 am

Izaak? Yeah, he’s capable.

Sunsettommy(@sunsetmpoutlookcom)
Editor
Reply to  Izaak Walton
January 20, 2022 7:46 pm

Bla bla bla, and yet you said everything that is wrong!

Dusty
Reply to  Izaak Walton
January 20, 2022 8:49 pm

The earth’s crust deforming is immaterial to the subject at hand, which is the glacier melting. As for that, the idea that, all other things being equal/controlled, some natural memory bank will parcel out the effects of 2022’s weather over the next few thousand years on the glaciers (and so on for each of the next few thousand years, too) is not plausible.

Each year comes to an end and the next year takes over where the last year left off.

Izaak Walton
Reply to  Dusty
January 20, 2022 11:11 pm

Dusty,
if you read the article you would see that the earth’s crust deforming changes the local sea level and thus the amount of the glacier that is above/below sea level which has a considerable effect on the dynamic. And it is slow.

Rational Db8
Reply to  Izaak Walton
January 21, 2022 1:24 pm

If you read the article, 1) it says nothing about deformation… and 2) the image shows that virtually none of the glaciers extend to the coastline.

What’s more, if you do your basic homework, I believe you’ll find that Greenland is undergoing postglacial rebound – not subsidence. In other words, it’s rising, not sinking. That’s because we’re in an interglacial period, rather than glacial period, so there’s far less ice on top of Greenland than there was the last glacial period.

So… sorry, but if you want to factor in deformation, it’ll make it less likely for more ice/ocean interactions, not more.

Dusty
Reply to  Rational Db8
January 22, 2022 1:04 pm

*Smiling* Seriously, I didn’t crib. I didn’t even know you were immediately below where I was replying until I hit post. If I had, I’d have just ditto’d yours as it is better.

Rational Db8
Reply to  Dusty
January 22, 2022 4:11 pm

No worries!! I think we’ve all been in that boat at some point. And thanks for the compliment, too!

Dusty
Reply to  Izaak Walton
January 22, 2022 12:57 pm

Izaak,

Thank you responding and i appreciate you directing my attention the part about the earth’s crust deforming. I breezed past it because i didn’t think it material.

Let me direct you to the map of Greenland at the top on the left and tell me how much of the (permanent) Greenland Ice Sheet overhangs the sea coast such that it is /will be affected by the mechanics you propose occurs. If you say zero, I’ll agree with you. In fact, with the ice sheet contained entirely on land any deformity from ice sheet loss will raise the sheet even further from the away from sea level leaving it at the mercy of only yearly weather with no additional effect beyond that year.

If you still think I’m wrong, please point out how or where. I’d be glad to change my mind if there is evidence I am.

Trying to Play Nice
Reply to  Dusty
January 22, 2022 3:23 pm

I think you hit the nail on the head. Even though it might be -60C, if there was a warm day 3000 years ago, the ice will surely melt today.

Vincent Causey
Reply to  Izaak Walton
January 21, 2022 12:01 am

Yes, if temperatures remained elevated for thousands of years as well, then the melting of the ice cap would take thousands of years. But if temperatures began to cool, say in the next decade, then it doesn’t mean that the Greenland ice caps would still be melting thousands of year from now just because of the warmer temperatures that pertained recently.

Rocketscientist
Reply to  Vincent Causey
January 21, 2022 7:27 am

No, it won’t continue to receive heat from a source that no longer is supplying heat.
Mathematically it is a convergent (stable) system when the forcing function (climatic) is at a higher frequency than the ability of the object upon which it acts to react.
The long term trend line of the forcing function will be the convergence curve, and I suspect that even that is cyclical.

Joao Martins
Reply to  Izaak Walton
January 21, 2022 3:16 am

… perhaps you could learn some science… eventually, your brains could respond in less than a couple of thousand years…

meiggs
Reply to  Izaak Walton
January 21, 2022 4:01 am

Seems like a relatively simple thermo question. Initial mass of ice, heat of fusion, net heat in from below and above + tidal cycles = energy in = eventual melting, climate aside it would take a long time to melt that much ice…if it happened real quick like meteor impact or major fault then an extinction event would be rather likely, for the period covered by the paper, looks like the thermal inertia of the ice does not dance in phase with the climate, makes perfect sense.

Jim Gorman
Reply to  Izaak Walton
January 21, 2022 5:55 am

Just when do you expect this interglacial to end? After 100,000+ years? Does this model ever show that new glaciation could occur in 5,000 or 10,000 years? If it never shows a new glaciation then the either the model or the inputs to the model is entirely bogus.

From usgs.gov:

“No one knows for sure. In the Devils Hole, Nevada, paleoclimate record, the last four interglacials lasted over ~20,000 years with the warmest portion being a relatively stable period of 10,000 to 15,000 years duration. This is consistent with what is seen in the Vostok ice core from Antarctica and several records of sea level high stands. These data suggest that an equally long duration should be inferred for the current interglacial period as well. Work in progress on Devils Hole data for the period 60,000 to 5,000 years ago indicates that current interglacial temperature conditions may have already persisted for 17,000 years. Other workers have suggested that the current interglacial might last tens of thousands of years.

Tens of thousand years is a lot less that 100 thousands of years.

Modeling only tells you what you want to hear. Wouldn’t it be great if pushing off the next glaciation is what CO2 is going to do? Funny how interpretations can be so different.

nyolci
Reply to  Jim Gorman
January 21, 2022 10:21 am

Just when do you expect this interglacial to end?

If it never shows a new glaciation

Have you read even just the abstract? Or this very short introduction above? Extremely stupid questions again.

Derg
Reply to  nyolci
January 22, 2022 10:23 am

No kidding, Izaak is as dumb as they come. Interesting coming from you.

MarkW
Reply to  Izaak Walton
January 21, 2022 9:25 am

Because ice responds slowly to temperature changes, therefor the climate model is accurate.

Is that really the position you want to take?

nyolci
Reply to  MarkW
January 21, 2022 10:23 am

Because ice responds slowly to temperature changes, therefor the climate model is accurate.

Is this how you understand the article above? FYI this is either a misunderstanding or a misrepresentation.

Rich Davis
Reply to  Izaak Walton
January 21, 2022 9:58 am

Izaak, of course mass change in an ice sheet that has survived through several interstadials is going to lag temperature changes for millennia. If the point is to try to “predict ice mass loss, and therefore sea level rise, accurately”, then that’s true as far as it goes. But the prospect of accurately modeling it and running the simulation for more than a hundred millennia is an obvious fool’s errand as was Willis’ point.

I wonder if you’ll concede the slightest point here and admit that the article’s thrust is that “ok sure, it’s not melting all that fast right now, but just wait and see what happens 2000 years from now!” They are not trying to say that the melting we are seeing today comes mostly from the Holocene Climate Optimum or something. They are trying to alarm us that today’s (bogusly-described by your tribe as unprecedented) temperatures are going to eventually lead to massive loss.

Sitting here holding my breath expecting you to concede the point…

Derg
Reply to  Izaak Walton
January 22, 2022 10:21 am

And do you think Benghazi was started by an internet video?

Climate clown indeed.

Scissor
Reply to  Willis Eschenbach
January 20, 2022 7:18 pm

I’m curious what it says about 120,009 years.

Paul Hurley (aka PaulH)
Reply to  Willis Eschenbach
January 21, 2022 5:52 am

Hey, now. You can make some pretty cool things with Tinkertoy™ 🙂

Tinkertoy-30-model-set.jpg
AGW is Not Science
Reply to  Paul Hurley (aka PaulH)
January 21, 2022 7:08 am

I’d rather have a Red Rider BB gun…

MarkW
Reply to  AGW is Not Science
January 21, 2022 9:31 am

How about a F-500 Fury Machine Gun cap gun

https://www.nicholscapguns.com/fury.htm

Paul Hurley (aka PaulH)
Reply to  AGW is Not Science
January 21, 2022 1:44 pm

Heck, I had a Secret Sam. 🙂

Kristi Silber
Reply to  Willis Eschenbach
January 21, 2022 11:27 pm

I haven’t visited this site for years, but thought I’d drop by to see what the “skeptics” are up to.

It’s hard to believe that Willis seems to be suggesting that not being able to predict next month’s weather is at all relevant, when that’s not what a model like this is designed to do. This is the kind of rhetoric I would expect of someone who has no understanding of these models, not someone who should have learned better after all these years – and he does know better, but it’s all part of the game to spread distrust of the science.

Robert Austin
Reply to  Kristi Silber
January 22, 2022 9:16 am

Kristi,
Does that mean that you have an better understanding of the models than Willis, or does it just mean that you trust the modellers when their models produce the “right” answers?

Derg
Reply to  Kristi Silber
January 22, 2022 10:24 am

Thanks for dropping by with your stupid science.

Bob Tisdale(@bobtisdale)
Editor
January 20, 2022 6:08 pm

The comments on this thread should be very entertaining. I’ll be back.

Regards,
Bob

Bryan A
Reply to  Bob Tisdale
January 20, 2022 7:26 pm

They COULD be

Thomas Gasloli
January 20, 2022 6:11 pm

The word “simulation/simulate” appears 5 times in the one paragraph abstract. No need to read further.

Zig Zag Wanderer
January 20, 2022 6:24 pm

So any current changes to Greenland’s ice has nothing to do with us?

Got it.

Robertvd
Reply to  Zig Zag Wanderer
January 21, 2022 1:15 am

Exactly. It were the Romans with Julius Caesar the worst of them. 

H.R.
Reply to  Robertvd
January 21, 2022 3:22 am

What did the Romans ever do for us?

Rocketscientist
Reply to  H.R.
January 21, 2022 8:27 am

Okay!…apart from sanitation, medicine, education, wine, public order, irrigation, roads, fresh water system, and public health what have they ever done for us?

Bill
Reply to  Rocketscientist
January 21, 2022 12:23 pm

Don’t forget wine…er? 🙂

another ian
Reply to  Rocketscientist
January 21, 2022 1:34 pm

Gave orgies a nudge – what is Latin for c/f?

whiten
Reply to  Robertvd
January 21, 2022 7:57 am

That actually is one of the points of “Holocene climate”.
Man’s impact and influence in climate even before Caesar or even Moses or “Queen” Nefertiti’s…

Surprised yet?

Rud Istvan
January 20, 2022 6:27 pm

Pathetic. They ignore ice core data, use models, and conclude nothing of ice relevance.

Doug
January 20, 2022 6:32 pm

It’s so nice to have a toy that will say just what you tell it to say

Izaak Walton
Reply to  Doug
January 20, 2022 7:06 pm

What like this:
 model projections indicate that the GrIS will probably contribute 5 cm to 33 cm sea level rise under the most extreme warming scenario (RCP8.5) by the end of 21th century [31106107]. This seems to indicate that the contribution of GrIS melting to sea level rise is only on the order of tens of centimetre, in the worst case. “

Bryan A
Reply to  Izaak Walton
January 20, 2022 7:16 pm

2″ – 13″ for the non-metric crowd

Clyde Spencer
Reply to  Izaak Walton
January 20, 2022 8:18 pm

What fraction of the GrIS would contribute 5 – 33 cm to the oceans? That will tell how many thousands of years they predict. You don’t have to guess.

As you should know, RCP 8.5 is improbable.

Redge
Reply to  Izaak Walton
January 20, 2022 11:13 pm

So their model “predicts” melting ice under RCP8.5 could raise the sea level by 5 cm possibly 33

RCP8.5 is highly unlikely even in the wettest dreams on climate sceance.

The IPCC admit RCP8.5 is highly unlikely but climate activists always use 8.5 to conjure up their scary scenarios.

Schneider would be so proud

whiten
Reply to  Redge
January 21, 2022 8:20 am

Izzak,
I do not think you understand at all what actually “Holocene climate” means, especially when treated as a “norm” in climate instead of an “anomaly”… as it seems to have being treated in this particular case.

MarkW
Reply to  whiten
January 21, 2022 9:34 am

It’s been about 5000 years since the Holocene Optimum ended.
Temperatures have been falling ever since.

Bob boder
Reply to  Izaak Walton
January 21, 2022 5:31 am

Yep from the Roman and mid evil warming they mean. So this warming period will cause more sea level rise 1000+ years from now. Got it.

Carlo, Monte
Reply to  Izaak Walton
January 21, 2022 7:41 am

seems to indicate” — says it all.

Dave Andrews
Reply to  Izaak Walton
January 21, 2022 8:21 am

Not even the BBC gives any credence to RCP 8.5

MarkW
Reply to  Izaak Walton
January 21, 2022 9:33 am

Too bad Greenland isn’t melting anywhere near as fast as the models say it should.

MiloCrabtree
Reply to  Doug
January 21, 2022 6:11 am

That’s what the deep state thinks about Brandon…

January 20, 2022 6:51 pm

As soon as I saw … “anthropogenic warming begins around 1850 AD” … I stopped reading. Personally, I’d like to see what Greenland looks like without all that ice.

Zig Zag Wanderer
Reply to  John Shewchuk
January 20, 2022 7:36 pm

Personally, I’d like to see what Greenland looks like without all that ice.

Just ask the Vikings

Reply to  Zig Zag Wanderer
January 20, 2022 7:49 pm

If enough ice melts, maybe they’ll return.

MarkW
Reply to  John Shewchuk
January 21, 2022 9:35 am

If you melt it, they will come.

Oldseadog
Reply to  John Shewchuk
January 21, 2022 2:33 am

The bedrock image at the top of the paper tells you what it would be like without ice.

For the authors’ next paper, perhaps they could tell us how they come to the conclusion that anthropogenic warming began in 1850 AD and what is the anthropogenic percentage compared to the total warming.

Rational Db8
Reply to  Oldseadog
January 21, 2022 1:33 pm

Especially considering the recent paper which used isotopic analysis on atmospheric CO2, showing that of all the CO2 increase that’s occurred, man is only responsible for a measly 12% of it. All the rest has come from natural sources, not all from man as the AGW proponents keep claiming.

2hotel9
January 20, 2022 6:52 pm

Really? So what moronic f*ck figured out reality does not fit their political agenda? Oh, yea, none of them.

Prjindigo
January 20, 2022 7:01 pm

I’m going to need a citation of an actual scientific STUDY that proves that this ‘climate change’ has happened and that it has happened for long enough to have an effect stronger than gravity with changes in albedo and magnetic field at the location of the subjective wildly asinine prediction. It had better not be based on a statistical linear progression of surface temperatures which indicate absolutely no change in the energy state of the Earth’s atmosphere.

DMacKenzie
January 20, 2022 7:03 pm

Having a complex computer model that nobody can take the time to check was a useful route to your Ph.D. dissertation. Most of the models gave answers that confirmed cherry-picked measurement data. I mean how you gonna get a Ph.D. if you say your model and your experiment bore no semblance of correlation ? Review committees are catching on….

Bob boder
Reply to  DMacKenzie
January 21, 2022 5:33 am

I doubt it’s very complex, since all relationships seem to linear

dk_
January 20, 2022 7:23 pm

Show that the same data set cannot be used to show that Antarctic Ice Volume predicts climate change. Take as long as you want…

DMacKenzie
January 20, 2022 7:27 pm

GrIS was not in equilibrium”….Well, if the air is getting warmer over a couple of decades, the ice will shrink. and if its getting colder, the ice will increase. Its simple heat transfer physics. A multi-thousand year phase shift means they have missed the causative factor.

David Sulik
January 20, 2022 7:32 pm

I’d like to see the data they used for the magma plume.

markl
January 20, 2022 7:59 pm

Opening 7 words got me”…Using transient climate forcings based on simulations” WTF does that even mean?

Clyde Spencer
Reply to  markl
January 20, 2022 8:20 pm

Translation: We’re trying to snow you.

Rocketscientist
Reply to  markl
January 21, 2022 8:35 am

It means they tried to get a huge thermal mass excited by imposing variable amplitude and frequency thermal forcing.
…and found a time lag.

They seem to not understand inertia.

There, I hope this clears things up.🤔

Clyde Spencer
January 20, 2022 8:06 pm

today’s climate could still be affecting its size in thousands of years’ time

That is an admission that they expect the Greenland ice sheet to still be around thousands of years from now.

Smart Rock
January 20, 2022 8:19 pm

These model-based daydreamers take no notice of very well known historical facts about Norse settlements in Greenland in the 10th to 14th centuries. They had cattle, they grew barley, they had churches, and there must have been enough trees to give them some firewood (even if they used peat for heat, you need a decent amount of dry wood to get a fire going; I’ve watched it being done). And that’s assuming that all the timber they used for construction came from Iceland in longships, which is – I suppose – possible). Not a lot of trees in Greenland even now.

Their statement that “Greenland’s climate was getting colder from the Holocene Thermal Maximum (i.e., 8 ka) to the Pre-Industrial era” displays so much ignorance that it’s hard to imagine it coming from educated adults. They must live in an imaginary model world that never touches the real world. But hey, Phil Jones opined that “we need to get rid of the MWP*” and so they did, in their world.

Although I will give them 1 out of 10 for acknowledging the existence of the Holocene Thermal Maximum. It used to be called the Holocene Thermal Optimum, but “thermal optimum” implies “the most ideal temperature” and everyone knows that “warm” = “bad”. It must have been awful in that Thermal Maximum – it’s a miracle that the human race survived the heat. Perhaps that’s where the concept of hell came from, watching the world burning around them, sea level rising, floods and droughts, heatwaves and blizzards, all at the same time. Because it was – gasp! – more than 2°C above the pre-industrial climate. That was a warning for the early proto-humans, who ignored it (it turns out that they were being paid off by Exxon Mobil and the Koch brothers) by starting to develop something they called “civilisation”, and look where that’s led us too, the brink of extinction for real this time!**

  • or words to that effect
  • /sarc
whiten
Reply to  Smart Rock
January 21, 2022 9:01 am

Smart Rock.

I can not tell what they exactly mean by the “Holocene Thermal Maximum”.

But that term, as things stand, is not even wrong.
The climate has a “Thermal Maximum”.
You are living in it, currently as we speak now, at the very present.
And as considered by the official climastrology, that we living in a Holocene climate period, then;

Holocene Thermal Maximum”, is not even wrong, as a termregardless of one or the other’s method to apply it.

cheers

MarkW
Reply to  Smart Rock
January 21, 2022 9:39 am

From the pictures I’ve seen, rock seems to have been the major building material.

Rational Db8
Reply to  MarkW
January 21, 2022 1:48 pm

Possibly – but the archeological evidence apparently shows that trees grew on Greenland when Vikings settled it. I wish I had a better link handy, but the one I was able to find quickly says that in fact they had to clear “Birch brush” to create the meadows they farmed. On the Vikings and Greenland – Watts Up With That?

Obviously there aren’t trees growing there now – e.g., it was clearly warmer when the Vikings were there than present day temps.

whiten
Reply to  MarkW
January 21, 2022 2:03 pm

MarkW

I know this will be strange to you,

But considering your reply to me in the other thread, above this one,

Thermal Maximum”, consist as a value beyond “Thermal Nominal”, at any given point, regardless of polarity, as in negative or positive direction.

So, regardless of it being or not in an actual climate thermal optimum period, still a climate thermal state, above the value of the climate thermal nominal, at any given point in time, could very much be within the territory of the climate “Thermal Maximum“.

At the very list, the way this climate “Thermal Maximum” term offered by this particular study, is clean from the anthropogenic pollution. even when named as a Holocene one.

An Interglacial thermal optimum does not consist as an Interglacial thermal maximum…
As simply as a thermal optimum state does not mean or consist to be a thermal maximum one.

Well, hopefully making sense here.

cheers

Last edited 4 months ago by whiten
Brian R
January 20, 2022 8:38 pm

So with this logic, the changes we are seeing today are not from recent climate changes but climate changes from thousands of years ago.

Rocketscientist
Reply to  Brian R
January 21, 2022 8:40 am

True, but I believe the doublespeak involved here is to argue that the reason why catastrophic change isn’t happening is that it will only happen 3000 years from now.

zee
January 20, 2022 10:02 pm

Article Title: Impact of paleoclimate on present and future evolution of the Greenland Ice Sheet

John
January 20, 2022 11:26 pm

The Tonga volcanic eruption will probably be more problematic than this simplistic view of academics

Mike Edwards
January 20, 2022 11:40 pm

So there is some deep contradiction going on within this paper.

From the abstract: “The maximum and minimum ice volume at around 18–17 ka
and 6–5 ka lag the respective extremes in climate by several thousand years, implying that
the ice volume response of the GrIS strongly lags climatic changes.” (my emphasis)

If that is really the case, then any climatic changes since 1850 should not be having any effect on the GrIS at the present time.

They can’t have it both ways – a time lag on the order of thousands of years in the earlier holocene and yet one with a lag less than 100 years now…

One thing that they do make clear is that the GrIS minimum since the end of the last ice age was at some time after the Holocene Thermal Maximum (HTM) – i.e. 5 to 6 thousand years ago, not the present day. A clear statement that current conditions are not as warm as the HTM. This is not only true regarding Greenland, but also applies to Glaciers around the world.

Graemethecat
Reply to  Mike Edwards
January 21, 2022 2:03 am

Logical consistency has never been a feature of Climate Alarmism.

AGW is Not Science
Reply to  Mike Edwards
January 21, 2022 7:14 am

Oh what tangled webs they weave…

fretslider
January 21, 2022 12:28 am

Astrology is way more fun and just as accurate

If I had sixpence for every [wasted] model run…

Bruce Cobb
January 21, 2022 2:48 am

What nonsense. “Climate change” does not cause future climate change. It is sheer stupidity and hubris to think that can control or affect what the climate does now, and certainly in the future. In thousands of years, and likely sooner than that, we will be in the grips of the next ice age. The Greenland ice sheet is not going to “remember” todays climate and think, “hey, I think I will shrink instead of grow. Because scientists said I could”.

tygrus
Reply to  Bruce Cobb
January 21, 2022 4:40 am

If I kept a large block of ice with +0.5C at the bottom & 0.01C at the top for many hours it would slowly melt to eventually be a wet puddle. The average temperature for 1hr does not melt all of the ice that will eventually melt. I can measure the rate of ice melting & estimate when it would completely be melted. Before it’s completely melted you could say “you still have ice, it mustn’t be warm enough to melt it all yet”. If I changed the top to be warmer around it then it should melt quicker. If I then increased the bottom temperature, how much more ice can be melted in the same time as before? It can be identical when the blocks are the same size & time sufficient to melt both. So it was really the 0.5C that did most of the damage, increasing the temperature overtime may hide our perception of how much that first 0.5C is responsible for.

Similarly, the amount of Ice/snow on Greenland is said to be proportionate to annual average temperature. The higher altitudes should be cooler than at sea level. But the current average temperature has to be kept the same for many years to see how much will eventually melt. So what they see is a work in progress. If average temperature is stabilised, how long will it take to stop seeing ice/snow net loss?

But what this does highlight is, they previously thought they knew the correct model but now they have to change it because it wasn’t matching reality. How much of the current melt could be climate change (eg. warming) that occurred centuries before industrial revolution vs latest human contribution? How much more melting will occur for many decades to come for our contribution to warming?

But making bad predictions for >100yrs into the future are unlikely to be proved bad within a research career (safe from harm). The more dire predictions appear to attract more attention & funding than those that show less danger. Group think is very dangerous.

MarkW
Reply to  tygrus
January 21, 2022 9:48 am

Another point is that if you have the entire block of ice at -5C and the air above the block warms by a couple of degrees, the top of the ice block will warm a bit, which then warms the bit under that, which then warms the bit under that, until you reach the bottom of the block. In other words, it takes time for the change in temperature to travel through the ice, even if the ice doesn’t melt.

As the ice warms, it will flow more easily, even if it doesn’t melt.

Joao Martins
January 21, 2022 3:13 am

More playing with computer models. This is not natural history. This is not climatology. This is a waste of taxpayers money.

Chris Wright
January 21, 2022 3:25 am

“Using transient climate forcing based on simulations….”
I stopped reading it right there.
“Garbage in, garbage out” doesn’t even begin to describe this nonsense. I could weep for the state of modern science.
One small ray of hope. It seems that finally the UK political establishment is waking up to the misuse of junk Covid models that stampeded the government into ruinous lockdowns. Who knows, maybe they’ll start to question the climate models as well….
Chris

ThinkingScientist
January 21, 2022 5:42 am

The authors need to take care with this statement as they are directly contradicting IPCC AR6 and might get cancelled or re-educated:

“…even though anthropogenic warming begins around 1850 AD”

Glacial retreat and sea-level level data suggest warming onset does indeed commence as early as 1830-1850. But IPCC AR6 temps and models do not support that storyline and certainly not that it could be anthropogenic. They indicate that AR6 agw forcings are way too small/insignificant in the period 1850-1910 to have caused anything and show flatlining models and temps until 1910. There are no warming forcings of any significance in the AR6 models over the period 1850 -1950.

There is a glaring inconsistency between glacial retreat data and AR6 forcings and model results.

Last edited 4 months ago by ThinkingScientist
Kip Hansen(@kiphansen2)
Editor
Reply to  ThinkingScientist
January 21, 2022 12:50 pm

Thinking ==> Agree (though I doubt that will be Cancelled). They just don’t seem to understand even the IPCC consensus view. It could, however, simply that they have “misspoken”. But if they have not simply made a silly error in the writing, then they are so far off-base that it negates the rest of their paper entirely.

ResourceGuy
January 21, 2022 7:18 am

Just keep saying that and label the cooling in the North Atlantic as a “warming hole” like the scared UK researchers like to say.

NOAA SST-NorthAtlantic GlobalMonthlyTempSince1979 With37monthRunningAverage.gif (880×481) (climate4you.com)

Andy Pattullo
January 21, 2022 7:50 am

Climate models resemble real climate the way fashion models resemble Walmart shoppers.

Kip Hansen(@kiphansen2)
Editor
January 21, 2022 8:43 am

Here’s a New One ! “even though anthropogenic warming begins around 1850 AD.”

That’s an entire century before the IPCC reckons AGW started warming anything.

The date they call “anthropogenic warming begins” the end of the LIA — long before anthropogenic CO2 began to rise sufficiently to do anything.

One could excuse this if it was some cigar smokin’ journo writing for a scandal sheet (like the NY Times…) , but this is in the paper’s abstract.

Patrick B
January 21, 2022 9:41 am

The idea that anyone views this as science is both horrifying and depressing.

Ian MacCulloch
January 21, 2022 2:16 pm

The authors of this paper (and many others like them) have yet to realize that there is a sharp distinction between the modern day ice sheet behaviour and the annual accumulation that has been going on for the last 1,000,000 years as witnessed by the deep drill holes including GRIP and Camp Century. The modelling of this paper does not discriminate between the two systems both of which are at odds with one another.

Ed Zuiderwijk
January 22, 2022 2:09 am

Oh yeah? Where does the heat go in the meantime?

Trying to Play Nice
Reply to  Ed Zuiderwijk
January 22, 2022 3:46 pm

I thought it goes deep in the ocean.

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