Inconvenient: new treeline paper suggests temperatures were warmer 9000 years ago

3 to 4 degrees centigrade warmer, in fact. Far greater than recent warming.

The new paper, Kulman et al. 2018 relies on paleoclimatology, which as we’ve learned from Mann, can be taken with a grain of salt.

Because trees may only grow within narrowly-defined temperature ranges and elevations above sea level, perhaps the most reliable means of assessing the air temperatures of past climates is to collect ancient treeline evidence.

In a new paper, Kullman (2018) found tree remnants at mountain sites 600 to 700 meters north of where the modern treeline ends, strongly implying Early Holocene air temperatures in northern Sweden were 3-4°C warmer than recent decades.

Kullman, 2018

“The present paper reports results from an extensive project aiming at the improved understanding of postglacial subalpine/alpine vegetation, treeline, glacier and climate history in the Scandes of northern Sweden. The main methodology is analyses of megafossil tree remnants, i.e. trunks, roots, and cones, recently exposed at the fringe of receding glaciers and snow/ice patches. This approach has a spatial resolution and accuracy, which exceeds any other option for tree cover reconstruction in high-altitude mountain landscapes.”

All recovered tree specimens originate from exceptionally high elevations, about 600-700 m atop of modern treeline positions.”

“Conservatively drawing on the latter figure and a summer temperature lapse rate of 0.6 °C per 100 m elevation (Laaksonen 1976), could a priori mean that summer temperatures were at least 4.2 °C warmer than present around 9,500 years before present. However, glacio-isostatic land uplift by at least 100 m since that time (Möller 1987; Påsse & Anderson 2005) implies that this figure has to be reduced to 3.6 °C higher than present-day levels, i.e. first decades of the 21st century. Evidently, this was the warmth peak of the Holocene, hitherto.”

“This inference concurs with paleoclimatic reconstructions from Europe and Greenland (Korhola et al. 2002; Bigler et al. 2003; Paus 2013; Luoto et al. 2014; Väliranta et al. 2015).”

This study adds seven new dates of mega fossil tree remnants (4 Betula, 2 Pinus, 1 Picea) to a

previous sample of 21 specimens from the same glacier (12 Betula, 9 Pinus) (Kullman &Öberg

2015). Individual dates are given in Table 1 and the samples are depicted in Figures 5-7. They range

in elevation between 1410 and 1275 m a.s.l., which is about 600 and 700 m higher than the nearest

present-day treelines of these species. The ages all represent the early Holocene, c. 11 200 to 6700

before present.

There’s also this new paper:

Greenland Ice Sheet 2-5°C Warmer With Much Lower Volume During The Early Holocene

Nielsen et al., 2018

The Holocene climatic optimum was a period 8–5 kyr ago when annual mean surface temperatures in Greenland were 2–3°C warmer than present-day values. … The initial mass loss in response to the temperature increase in the early Holocene is largest when forcing the ice sheet with the temperature and accumulation reconstructions from Gkinis and others (2014) (Experiment 5). In this simulation, temperature anomalies peak at more than 5°C above the present-day reference climate in the early Holocene and the ice sheet loses 20% of its volume in the 3000 years following the onset of the Holocene through increased surface melting.”

“The largest and most rapid retreat of the ice sheet was found for Experiment 5, which was forced by the temperature and accumulation reconstructions of Gkinis and others (2014). In this temperature reconstruction, temperature increases rapidly at the onset of the interglacial and has several shorter periods with temperatures more than 5°C above present in the early Holocene. .. Geological evidence suggests further that the ice-sheet margins in the southwest retreated up to  100 km behind their present-day position during the mid-Holocene (Funder and others, 2011). This evidence is further supported by interpretations of relative sea-level records and bedrock uplift rates that also point towards ice sheet retreat beyond the present ice volume in the mid-Holocene (Khan and others, 2008; Funder and others, 2011; Lecavalier and others, 2014).”

We find that the ice sheet retreats to a minimum volume of 0.15–1.2 m sea-level equivalent smaller than present in the early or mid-Holocene when forcing an ice-sheet model with temperature reconstructions that contain a climatic optimum, and that the ice sheet has continued to recover from this minimum up to present day.”

Graph Source: Nielsen et al., 2018 and Briner et al., 2016

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joelobryan

“600 to 700 meters north of where the modern treeline ends”

Higher, not north.

Ed Zuiderwijk

Higher in the context is synonymous with north. Because when the treeline moves higher it also moves north.

Not if you’re at the northern-most base of a mountain located in the northern hemisphere. Just being a nit-noid.

E J Zuiderwijk

In the context higher equals north. Because when the tree line moves higher it also moves northward.

Hugs

Hereabouts, 100 m up / 0.6K warmer matches about 100km northwards. Different by factor of 1000.

Ed Zuiderwijk

In the context higher is synonymous to north. Because if the treeline goes higher it also moves north.

tty

Not in Scandinavia. The mountain chain is north-south, so the treeline moves east-west.

Nylo

No way. A 600 metres higher tree line is a huge change. 600 metres further North, however, is an almost ridiculously small ammount.

Rod Everson

From the article: “All recovered tree specimens originate from exceptionally high elevations, about 600-700 m atop of modern treeline positions.”

They’re talking elevations, not distances. And the preceding discussion in the article should say “higher” not “north” as Mr. O’Bryan stated. “Higher” is obviously not synonymous with “north.”

Captain Trips

In the wonderful world of the English language, the phrase “north of ” is synonymous with “greater than “. So, in this case, “north of” is used correctly, albeit possibly confusing.

WXcycles

Certainly not common usage.

Tom Halla

So almost all life on earth was extinguished eight thousand years ago? After all, it was 5 degrees C warmer than present, and we all know 2 degrees will be catastrophic?/sarc

Javier

3.6° warmer at summer at the Swedish Scandes. Doesn’t mean that the yearly anomaly was that much warmer elsewhere. The northern summer insolation was really high at the time producing very warm summers at very high latitudes. Globally I have estimated ~ +1.2-1.5°C warmer than the LIA, or about 06-0.8°C warmer than now.

Paul Penrose

I believe Tom was referencing the Nielsen paper which states up to 5 degrees C warmer 8K to 5K years ago.

paqyfelyc

May be, but then obviously Nielsen applied to Greenland, not the whole planet, so Javier point still stand.

Samuel C Cogar

How about 7.0°C warmer than modern, 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.

Source: http://www.sciencedirect.com/science/article/pii/S0033589499921233

Hugs

But Samuel, surely should the methane deposits have leaked and caused a runaway warming! /sarc

“I believe Tom was referencing the Nielsen paper which states up to 5 degrees C warmer 8K to 5K years ago.”
But it doesn’t state that. That’s just Kenneth Richard stretching it again. The actual quote is there on the page
“The Holocene climatic optimum was a period 8–5 kyr ago when annual mean surface temperatures in Greenland were 2–3°C warmer than present-day values.”

Andrew Cooke

Not being snarky. I am asking an honest question. How do you come up with your inference of northern summer insolation and the knowledge that it was cooler everywhere else?

beng135

Don’t know if it was cooler everywhere else, but w/the summer insolation high in the northern hemisphere at that time, the summer insolation will be correspondingly low in the southern hemisphere.

Javier

Insolation is known with great precision for millions of years in the past to millions of years in the future from orbital calculations.

It wasn’t cooler everywhere else. The anomaly respect current temperature was smaller as you got closer to the tropics, but the tropics were warmer than the higher latitudes, as always.

There’s lot of information about past climate conditions from proxies. If you are interested you can start in these two articles I wrote and continue with the bibliography linked at the end. It is a small fraction of what I’ve read about the issue.

https://judithcurry.com/2017/04/30/nature-unbound-iii-holocene-climate-variability-part-a/

https://judithcurry.com/2017/05/28/nature-unbound-iii-holocene-climate-variability-part-b/

Javier, I think you mean relative insolation is known with great precision for millions of years in the past to millions of years in the future. That is, we know how isolation varies with latitude.

But we don’t know how constant the “solar constant” was or will be, over timescales of millions of years.

We have compelling evidence that TSI doesn’t change very much over periods of a few decades, even as solar cycles wane and wax in strength.

Does that mean it doesn’t change over periods of a few centuries? Perhaps. But the evidence is certainly weaker.

How about a few millenia? We really don’t have any way of knowing.

How about a few tens of millenia? Seriously?? We have absolutely no clue!

How about a few hundreds of millenia? Ditto, but 10× more so.

How about thousands of millenia? You’ve got to be joking!

Javier

The evidence that we have is that solar variability over the past 12,000 years was not bigger than solar variability over the past 700 years. And we have zero evidence that it has changed more than that for hundreds of thousands of years.

And if you think that solar variability can have more effect that changes of insolation due to precession and obliquity over the past 12,000 years, you are pretty much alone with your conjecture. In terms of energetics, orbital-caused changes of insolation are much, much bigger than solar variability.

Samuel C Cogar

Excerpted from article:

Greenland Ice Sheet 2-5°C Warmer With Much Lower Volume During The Early Holocene

In this simulation, temperature anomalies peak at more than 5°C above the present-day reference climate in the early Holocene and the ice sheet loses 20% of its volume in the 3000 years following the onset of the Holocene through increased surface melting.”

The following cited study estimates that the mean July temperatures along the northern coastline of Russia may have been 2.5° to 7.0°C warmer than modern, during the 5000+ years following the onset of the Holocene (10,000 yr BP).
Study source: http://www.sciencedirect.com/science/article/pii/S0033589499921233
Or see my post below,

So, iffen it was that extra warm along the northern coastline of Russia, for 5,000 years, then “YES”, the temperatures in Greenland pretty much had to be extra warm for 5,000 years also.

And “YES”, the Greenland ice sheet could have lost 20% or moreof its volume during those 5,000 years of extra warm temperatures.

And iffen it is settled Science that, to wit:

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. http://en.wikipedia.org/wiki/File:Holocene_Temperature_Variations.png

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. http://schools-wikipedia.org/images/439/43917.png

Now given all the above, would someone please answer my following questions which are:

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

2. Did the GIS also start quickly melting at 18,000 years BP, …… or did it start quickly melting at 15,000 years BP …… or did it start quickly melting at 10,000 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?

Cheers

Javier

Oldest Greenland ice cores go to about 125,000 years ago, so Greenland has had an ice sheet for at least that long.

Samuel C Cogar

Javier – June 1, 2018 at 9:56 am

Oldest Greenland ice cores go to about 125,000 years ago, so Greenland has had an ice sheet for at least that long.

Just what possible reason would a knowledgeable person have for claiming that Greenland ice cores “date” the glacier ice to be about 125,000 years old, ……… given the fact that it is highly likely that the Greenland ice sheet (glaciers) was subjected to 5,000+- years of exacerbated “melting” due to summer temperatures that may have been 2.5° to 7.0°C warmer than modern, …….. that occurred during the Holocene Climate Optimum, ….. from 8,500 years BP to 4,000 years BP?

Just how many “annual layers” of ice could have melted away from atop the Greenland ice sheet in the 5,000 years of the Holocene Climate Optimum?

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Javier

Just how many “annual layers” of ice could have melted away from atop the Greenland ice sheet in the 5,000 years of the Holocene Climate Optimum?

Not a single one from the cores taken at Central Greenland locations without lateral flow. The way it works the Greenland Ice Sheet melts from the bottom due to geothermal heat, and from the sides from melting at the margins of the ice sheet. There is also lateral flow towards the margins. But every single year, regardless of temperature, there is more snow precipitation in Central Greenland than surface melting. The higher the temperatures, the higher the snowing. That’s why every single annual layer from the present interglacial has been identified and counted in Central Greenland ice cores.

Rasmussen, S. O., Andersen, K. K., Svensson, A. M., Steffensen, J. P., Vinther, B. M., Clausen, H. B., … & Bigler, M. (2006). A new Greenland ice core chronology for the last glacial termination. Journal of Geophysical Research: Atmospheres, 111(D6).
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2005JD006079

Samuel C Cogar

Javier – June 1, 2018 at 3:56 pm

The way it works the Greenland Ice Sheet melts from the bottom due to geothermal heat, …………. [snip] …… But every single year, regardless of temperature, there is more snow precipitation in Central Greenland than surface melting. The higher the temperatures, the higher the snowing. That’s why every single [125,000] annual layer[s] from the present interglacial has been identified and counted in Central Greenland ice cores.

“Yes”, Javier, I comprehend your claim that the Central Greenland ice sheet was “core drilled” down to bare rock (gravel or dirt) and the “annual layers (rings)” in said ice core were carefully counted with the total being 125,000, ….. thus inferring that the bottom or lowest “annual layer” of ice was first deposited 125,000 years BP (before present) as an accumulated annual layer of “snowfall”.

And, therein are my problems, ….. Javier.

The 1st one being, ….. iffen the Greenland Ice Sheet melts from the bottom due to geothermal heat, …………. then how many “annual” layers of ice has melted off the bottom of the ice sheet during the past 125,000 years? If you can provide factual evidence that there was NO geothermal melting at the location(s) where the “ice cores” were removed, ….. then and only then, can you claim that the ice sheet is 125,000 years old.

The 2nd one being, ….. how can you or anyone else honestly claim that …. “every single year, regardless of temperature, there is more snow precipitation in Central Greenland than surface melting”, ….. when we know for a fact that temperatures in the far northern latitudes were extremely warm during the 5,000+ years of the Holocene Climate Optimum, ….. which was far, far “warmer” than during the Roman Warm Period when horrendous amounts of snow and glacial ice melted, that permitted Hannibal, his 50,000 soldiers and herd of war elephants, to cross over the Alp Mountains from the north and launch a “surprise” attack on Rome and to defeat the Roman Legions and sack the City of Rome. …… Do they have “ice cores” from the Alps that ALSO tell them how old those glacier ice sheets are?

And the 3rd one being, ….. if the Central Greenland ice sheet, according to the “ice core(s)”, …. is only 125,000 years old, then apparently, according to the following “temperature proxy graph”, …..the entire CG ice sheet completely melted away during the last Interglacial (135K BP) that occurred PRIOR TO 125K years ago, ……. and has since reformed via yearly snowfalls …….. without any geothermal “bottom” melting and/or without any solar induced “top” melting or sublimation , …… but how could that possibly be true IF the current Interglacial temperatures are pretty much exactly the same as the temperatures during the last Interglacial?

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Javier

Samuel, you should read more and conclude less about things that are known. The counting of annual layers goes to 42,000 years ago, but the cores are dated to the bottom by a variety of methods, including tephra layers from known and dated volcanic eruptions from the past. I don’t need to provide evidence of anything. It is all published and available in this era of internet. And yes, we can honestly say that every single year there was more snowing that melting at Central Greenland because there are no gaps in the ice cores. The annual layers have been identified for the entire Holocene and their age has been independently confirmed.

That Hannibal was able to cross the Alps doesn’t says anything about the conditions. He had a very hard time and lost quite a few men and elephants in the crossing, and we don’t know if he was particularly lucky with the weather that year. You could cross the Alps with elephants almost any year nowadays except that you wouldn’t get a permit for it. The Tour de France goes every year through the Alps, so it can be done with bicycles too.

We don’t know if the GIS melted completely or not during the past interglacial. Probably not. What we do know is that the past interglacial was significantly warmer than the present one. And we know that from different kind of evidence, including a higher sea level at the time by several meters.

And, therein are my problems, ….. Javier.

I would say that your main problem is having too many opinions and too little reading. The things you talk about have been researched for decades by very intelligent, very dedicated people with a lot more means. And they have published about the evidence they have uncovered.

Samuel C Cogar

Javier – June 2, 2018 at 10:54 am

Samuel, you should read more and conclude less about things that are known.

Shur nuff, Javier, …….. and which one of the following two (2) scientifically known facts should I be reading more about in order to become partially intelligent as you are, to wit:

Studies worry: Is Greenland on thin ice?

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, …………… 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.

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.

https://wattsupwiththat.com/2016/12/studies-worry-is-greenland-on-thin-ice/

Javier – June 2, 2018 at 10:54 am

The counting of annual layers goes to 42,000 years ago,.

OH MY, MY, Javier, now you are claiming that “The counting of annual layers goes to 42,000 years ago”, ……. where before you were claiming that “The counting of annual layers goes to 125,000 years ago”. Do I have a reading comprehension problem, ….. or what?

……. but the cores are dated to the bottom by a variety of methods, including tephra layers from known and dated volcanic eruptions from the past.

“YUP”, I believe, I believe. But my question is, ….. do they use the same “fuzzy math” calculations and “junk science” associations, correlations and/or insinuations for “dating” those annual layers in the ice cores ………. as they do for calculating past atmospheric CO2 ppm quantities based on the quantity of CO2 that is entrapped in the individual “annual layers” of the ice cores?

Javier, concerning the “entrapment” of atmospheric CO2 in the individual “annual layers” of snowpack atop a glacier, “getta clue”, …… individual “annual layers” of snowpack atop a glacier are NEVER the result of a single “snowfall”, but are the haphazard accumulation of multiple snowfalls AND the haphazard accumulation of multiple instances of “wind-driven” drifting of the falling snow … as well as the drifting of the snowpack that had previously fallen. And least we forget, atmospheric CO2 ppm quantities are reduced during periods of snowfall (low pressure), whereas said quantities are increased during periods of clear skies (high pressure).

Paleo atmospheric CO2 proxy quantities derived via use of glacier “ice cores” is far more FUBAR than is the US historical near-surface Temperature Record from 1870 to present.

I would say that your main problem is having too many opinions and too little reading. The things you talk about have been researched for decades by very intelligent, very dedicated people with a lot more means. And they have published about the evidence they have uncovered.

Nope, I am an “original thinker”, with fantastic attributes of memory recall, common sense thinking, logical reasoning and intelligent deductions ….. which are the “cause” of your main problem. And ps, Javier, I could probably list a dozen “things” …… “that had been researched for decades by very intelligent, very dedicated people who have published about the evidence they have uncovered” …… that have since been proven to be little more than “wishful thinking” junk science or intentional false claims.

Javier

which one of the following two (2) scientifically known facts should I be reading more about

You have trouble distinguishing scientific evidence, scientific fact, and scientist’s hypothesis or opinion.

Those two papers present evidence and the authors make hypotheses. Evidence can be partial and contradictory.

Facts are things that we know to be true. For example radiocarbon dating based on ¹⁴C measurements in ancient tree-rings. The measurements can be improved but the basis is a fact.

That ice-core layers identified in some Greenland ice cores represent annual layers, and that they expand the entire Holocene is also a fact.

OH MY, MY, Javier, now you are claiming that “The counting of annual layers goes to 42,000 years ago”, ……. where before you were claiming that “The counting of annual layers goes to 125,000 years ago”. Do I have a reading comprehension problem, ….. or what?

Certainly you have not only a reading comprehension problem, but also you invent things. I have never claimed that the counting of annual layers goes back 125,000 years. Reread my comments to see if you can understand what I have said.

“YUP”, I believe, I believe.

Science is not about believing. It is exactly the opposite of believing. You don’t seem to understand what science is about.

I am an “original thinker”, with fantastic attributes of memory recall, common sense thinking, logical reasoning and intelligent deductions

Good for you. Your weakness appears to be a knack for getting things wrong. A risk for independent thinkers that requires that they are solidly grounded in knowledge to avoid getting lost. Every proposer of a crazy theory is an independent thinker, and very few of them turn out to be right.

Hannibal didn’t sack Rome. Rome sacked him.

Now as far as the science goes….. no clue

Samuel C Cogar

Hannibal didn’t sack Rome. Rome sacked him.

“HA”, right you are, DNA, …… but then you made the same mistake that I did.

Hannibal didn’t sack Rome (the city), …… and Rome (the city) didn’t sack Hannibal.

Samuel C Cogar

Javier – June 3, 2018 at 3:39 pm

You (Sam C) have trouble distinguishing scientific evidence, scientific fact, and scientist’s hypothesis or opinion.

Certainly you (Sam C) have not only a reading comprehension problem, but also you invent things.

Science is not about believing. It is exactly the opposite of believing. You (Sam C) don’t seem to understand what science is about.

Your (Sam C’s) weakness appears to be a knack for getting things wrong.

Javier, you are 110% correct in your assessment of my inabilities, my failures, my miseducation and my learning-disabled utter ignorance of both the biological and physical sciences that pertain to the “natural world” of planet earth. Therefore, I apologize for attempting to “hoodwink” you into believing things that sound “sciency” that your mentors never authorized you to accept as potentially factual science.

And Javier, this commentary of yours really has me “scratching my noggin” in hopes of figuring out how the “experts” can get accurate counts of glacial ice core “annual layers” for determining geologic age of the ice, …… to wit:

Posted by Javier on June 1, 2018 at 3:56 pm
Not a single one (annual layer) from the cores taken at Central Greenland locations without lateral flow. The way it works the Greenland Ice Sheet melts from the bottom due to geothermal heat, and from the sides from melting at the margins of the ice sheet. There is also lateral flow towards the margins. But every single year, regardless of temperature, there is more snow precipitation in Central Greenland than surface melting. The higher the temperatures, the higher the snowing. That’s why every single annual layer from the present interglacial has been identified and counted in Central Greenland ice cores.

So, the Central Greenland glaciers are “increasing” in height due to annual snowfall [that eventually becomes an “annual layer” of glacier ice], ….. “melting” on the underneath (bottom), ……. “melting” on the margins …….and also “flowing” laterally (downhill) due to the force of gravity.

OH, MY, MY, ……. iffen those “annual layers” of glacial ice are constantly “flowing” laterally (downhill) due to the force of gravity, ….. how is it possible to extract an “ice core” from the top of the glacier, or anywhere “down slope” from the top of the glacier. ….. and determine an “age” by counting the “annual layers”?

“DUH”, the older an “annual layer” of glacial is, …… the farther “down slope” (downhill) it has laterally “flowed”.

Now one can determine the “age” of a tree by counting the annual “growth rings”, but the counting of those “rings” has to be performed at the base of the tree, not at the top of the tree, nor at the middle of the tree trunk.

You have “bested” me, … Javier, …… so I concede to you as the resident expert on all things “sciency”.

Cheers

Javier

how is it possible to extract an “ice core” from the top of the glacier, or anywhere “down slope” from the top of the glacier. ….. and determine an “age” by counting the “annual layers”?

Easy enough. Scientists are smart enough to have figured, decades before you even thought about this problem, its solution. They take the ice cores from the top of ice domes where the lateral flux is not only minimal, but outward in all directions, thus preserving the vertical structure of the ice and its layers unaltered.

So yes, they count layers in tree rings and in ice cores by going perpendicular to the layers at the place where they are best preserved and least disturbed.

The results they get are consistent with lots of information coming from different disciplines. For example by looking at lead contamination in annual layers, they get the right dates for the contamination coming from Roman mines that are known from historic sources, as was discussed recently here at WUWT.

So you can doubt all you want, and be a wisecrack all you want. It is the waste of your time. Mine ends here.

Sam C Cogar

They take the ice cores from the top of ice domes where the lateral flux is not only minimal, but outward in all directions,

Try again, ….. Javier, ……. the “annual layers” of glacial ice can not be STRECHED downslope from the top of the glacier ….. anymore than it can be STRECHED outward (laterally) across the face of the glacier. Ice doesn’t bend or stretch, …… it breaks, fractures or melts.
Join the discussion…

The frequency of melt days at the top of the Greenland Ice Sheet (GIS) is about 1 in 150 years. The last one was on 8 July 2012, the penultimate was in 1889. Possibly that frequency was higher during the Holocene Climate Optimum but still far too low to remove any precipitation.
If the GIS completely melted in the early Holocene it could not rebuild because the snowline would be above the topography.

Sam C Cogar

So sayith: teerhuis

The frequency of melt days at the top of the Greenland Ice Sheet (GIS) is about 1 in 150 years.

Possibly that frequency was higher during the Holocene Climate Optimum but still far too low to remove any precipitation.

Now Javier will surely agree with you ……… but the authors of this study probably won’t, to wit:

The resulting volume changes of the Greenland ice sheet during the Holocene from the experiments are shown in Figure 2. The six different temperature reconstructions lead to two different characteristic histories of ice-sheet volume during this period. Either (1) continuous volume loss during the Holocene, stabilizing in the last few millennia close to the observed present-day ice sheet volume, or (2) an average negative mass balance in the early Holocene leading to a minimum mid-Holocene ice sheet, followed by a period of a small decreasing positive mass balance on average in the late Holocene, ending in a similar volume of the ice sheet as the other experiments.

In this simulation, temperature anomalies peak at more than 5°C above the present-day reference climate in the early Holocene and the ice sheet loses 20% of its volume in the 3000 years following the onset of the Holocene through increased surface melting (see Figs 2, 3).

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/1B273853FF3CE712602B3AA90A0E57DB/S0022143018000400a.pdf/effect_of_a_holocene_climatic_optimum_on_the_evolution_of_the_greenland_ice_sheet_during_the_last_10_kyr.pdf

Ken

Why was the tipping point not passed? I am surprised that Earth’s atmosphere did not morph into a Pluto-like hell.

Sparky

I guess they will file it under local event to Europe,like they tried to do with the MWP…at least until similar studies start coming in from around the world

No matter how many studies prove the worldwide reality of the MWP, and there are thousands, rent seekers will deny and dismiss and continue to repeat Michael Mann’s favorite lie …

Philip Mulholland

Even locating tree lines can be deceptive if you include spruce clones that are adapted to living as ground hugging shrubs and survive for millennia protected beneath the annual winter snow cover.
9,500-Year-Old Tree Found in Sweden Is The World’s Oldest Tree
https://www.boredpanda.com/worlds-oldest-tree-old-tjikko-sweden/

Grant

It’s a clone from a root system. The tree is a couple hundred years old I think. Oldest tree is a bristlecone. As the article notes, a much older system in Utah exists, estimated to be 80,000 years old.

Felix

Italy has the oldest tree in Europe which looks like a tree:

https://www.atlasobscura.com/articles/whats-oldest-tree-in-europe

tty

That clone was found and published by Kullman (not Kulman), so he is not unfamiliar with the phenomenon. This paper deal with subfossil remains of full-grown trees.

coaldust

Do you believe us or the lying trees?

Salvatore Del Prete

Exactly correct and the temperature trend overall since then has been down with warm spikes at times such as the Medieval warm period, modern warm period (which will be ending very soon), Minoan and Roman warm periods.)

Sine the Holocene Optimum Milankovitch Cycles have ben in a cooling trend for the big picture while solar activity changes within the big cooling picture have accounted for the irregularity of the pattern. Superimposed on this is volcanic activity.

Now with not only weak solar magnetic fields but also a weakening geo magnetic field(which will compound given solar effects) the global warming which was slight (some .8c since the end of the Little Ice Age) should be coming to a close with year 2018 being a transitional year.

So funny: ” at mountain sites 600 to 700 meters north of where the modern treeline ends”

The directionally challenged author doesn’t know the difference between “north” and “up.”

M Courtney

Maps are confusing.

French

Are you sure you can translate the paper back into Swedish and get It all correct?

north can mean above. please see or google dictionary meaning of north.

jim hogg

As Paul has also said, north can be, and often is, used as a synonym of above etc . . . So, maybe not so funny, and maybe not so directionally challenged either . . .

paul courtney

Remy: So long as it allows alarmi$ts to avoid the substance of the article. It’s good that you can laugh as your theory swirls down the drain.

John Harmsworth

Michael Mann ( oh Great and Wise One) found the One Tree, that reveals the totality of Earth’s history! His wisdom and unique insight is revealed to all through His “Magic Algorithm”, which takes in garbage and spins it into career Gold!
All other trees living and dead, anywhere in the world, LIE!

This is The Truth of Mikey Mann!

Komrade Kuma

Amen, St John. You speaketh the Truth of Mann who actually walks among us!

Felix

There is but One True Tree, and Mann is its Prophet!

Who profits thereby.

John Harmsworth

Surely there is evidence of a change in the tree line elsewhere in the world to either refute or corroborate this very isolated information. Himalayas? Southern Rockies? Southern Hemisphere? Urals? Mongolia?

R. Shearer

Tree and plant remains are being revealed at a number receding glacial sites all indicating a warmer past.

Javier

Of course. Run a search in Google Scholar. There are scores of articles on the issue for decades.

joelobryan

The evidence is all over the place.

Holocene tree line changes in the Canadian Cordillera are controlled by climate and topography
“At two lakes (Windy and Redmountain), tree macrofossil concentrations were highest in the warmer‐than‐present Early Holocene (11,700–7000 cal. bp), indicating higher forest density and tree line position during this time period. ”
https://onlinelibrary.wiley.com/doi/abs/10.1111/jbi.12904

“It is difficult to get a man to understand something, when his salary depends on his not understanding it.”
– Upton Sinclair,

John

Yes, this is old news. Hubert lamb worked out tree lines in a number of locations including Britain and the alps.

E Roy ladurie wrote an excellent book ‘times of feast times of famine ‘ which recorded higher tree lines and also crop plantings back thousands of years again in the alps.

The trouble is that this sort of work is no longer fashionable and these papers and books lie unread in the libraries of the world. If it hasn’t been digitised it doesn’t exist for many researchers who rely on the Internet.

Tonyb

nw sage

Do you mean that people used to actually write on PAPER? What was the world coming to!

Javier

Leif Kullman has been publishing articles on the treeline in the Swedish Scandes since at least 1979, and saying inconvenient things like most of the recent advance took place before 1950. Not that it has mattered much until now.

That the Holocene Climatic Optimum was warmer than now, at least during the summers, it is very well established by treeline studies. This graph is from:

Reasoner, M. A., & Tinner, W. (2009). Holocene treeline fluctuations. In Encyclopedia of Paleoclimatology and Ancient Environments (pp. 442-446). Springer Netherlands.

comment image

I used it at this WUWT article from January:
https://wattsupwiththat.com/2018/01/what-are-in-fact-the-grounds-for-concern-about-global-warming/

J Mac

6F to 7F warmer than today? Wow!
My Scottish ancestors must have been wearing mini-kilts… and stocking their sporrans with cool libations!

Seriously, this is a very revealing study and another substantiation for natural climate change.

Leo Smith

Indeed. Have a look at what’s left of the Orkney civilisations at e.h. Skara Brae and it appears that what is now a cold desolate wasteland with almost no agriculture was then a thriving community.,

Ed Zuiderwijk

Archeological evidence aplenty showing that during the Roman optimum the Picts were growing barleys in what is now Scotland which can’t be grown there now, because it’s too cold.

Ben Vorlich

If memories of my youth in Central Perth shire aren’t misleading me I think that on various mountain tops there are/we’re tree stumps under 10+ ft of peat. These are at an altitude well above where commercial plantations ended.

joelobryan

The evidence that End Holocene is at hand and the next glacial period was commencing seemed pretty conclusive in 1975 to many climate experts of that day.

The fact that Norse pastoral colonies existed 800 years Before Present (BP) at many sites in southern Greenland, where none could exist today due to frozen ground and cold summers, is the kind of in your face evidence the climate alarmists have to hand wave away.

The fact that Romans had occupations with their precious vineyards to make wine in northern England, where none could exist today, is the kind of in your face evidence the climate alarmists have to hand wave away.

At Alaska’s Mendenhall Glacier, many tree stumps have emerged over the years that conclusively radio-carbon date to various dates between 1,400 to 2,350 years BP, but have been buried under ice for a thousand years or more.
http://juneauempire.com/outdoors/2013-09-13/ancient-trees-emerge-frozen-forest-tomb

All that evidence is ignored by the alarmists. Just as they will ignore this evidence of a warmer Swedish climate 7Ka to 9Ka BP with a much higher tree line than today.

Sadly, the evidence that End Holocene is approaching doesn’t pay research grants like alarmist stories regarding TheMagicMolecule. MagicMolecule fairy-tales provide rationale for seizing more power for the politically receptive socialist politicians and their crony capitalists looking to cash-in on green renewable energy hustles.

Rich Davis

Sadly, the evidence that End Holocene is approaching doesn’t pay research grants like alarmist stories regarding TheMagicMolecule. MagicMolecule fairy-tales provide rationale for seizing more power for the politically receptive socialist politicians and their crony capitalists looking to cash-in on green renewable energy hustles.

Joel,
No worries, as soon as it becomes totally impossible to ignore the cooling, the Mannites will suddenly discover that CO2 may cause global cooling after all. Much, MUCH more funding is needed to study it. Far more than was spent on Climate Change (TM) in the past, because obviously we didn’t spend enough and the massive cuts in spending are the reason why “mistakes were made”. (But what is the point of assigning blame? Let’s focus on fixing this!)

And guess what? The solution to the problem will turn out to be EXACTLY the same. Stop burning fossil fuels, we need more socialism. Cut the human population by 90%. It’s much worse than we thought. 27 of the coldest years have been in the past decade. The poor are hardest hit. Save the planet for … The Children.

They won’t even need to re-brand. Climate Change (TM) will still be operative. Ehrlich will write more books about our imminent doom, and the rent seekers and subsidy farmers will all live happily ever after.

Jacob Frank

I’m sure they will say the temperature was only regional

Javier

Well, it was not global, that’s for sure. The pattern of insolation was very different.

AGW is not Science

Yes it was, because when they speak of “global “ temperature/climate today they’re talking about the global AVERAGE, which would have been much higher then. The pattern of insolation may indeed have been different, but average temps would have been higher. Just as the MWP was global AND warmer than the present.

Javier

The pattern of insolation may indeed have been different, but average temps would have been higher. Just as the MWP was global AND warmer than the present.

You don’t know any of this for certain. We have almost no knowledge of global temperatures in the past, as every single proxy is local. I’ve read many. many papers dealing with proxy temperatures and there is no way to say if the MWP was warmer than the present or not. Some proxies say yes, others say no, and they are all local. You might choose to believe otherwise, but you lack the evidence to prove it. And no. Selecting your favorite proxies does not count as proof.

Harry Twinotter

“We have almost no knowledge of global temperatures in the past, as every single proxy is local”.

That is not true. If you have proxies from different locations around the global you can indeed estimate the Global Mean Temperature at that time.

But I agree the MWP is uncertain both spatially and across time. I have never seen a denier post good evidence for the MWP (that old Lamb schematic does not count). I go with the theory the MWP was not really global warming, it was more a redistribution of heat ie some places got warmer while others got colder.

Javier

If you have proxies from different locations around the global you can indeed estimate the Global Mean Temperature at that time.

The only one that has done it so far is Marcott et al., 2013.

John F. Hultquist

Historical Aspects of the Northern Canadian Treeline HARVEY NICHOLS

http://pubs.aina.ucalgary.ca/arctic/Arctic29-1-38.pdf

ABSTRACT From palynological studies it appears that northernmost dwarf spruces of the tundra and parts of the forest-tundra boundary may be relicts from times of prior warmth, and if felled might not regenerate. This disequilibrium may help explain the partial incongruence of modern climatic limits with the present forest edge. Seedlings established as a result of recent warming should therefore be found within the northernmost woodlands rather than in the southern tundra.

Eben

What do you mean “paper suggests” was it or was it not , suggesting is not science.

paqyfelyc

“suggesting” may be science, just like “we don’t know” or “we aren’t sure”. Obviously, trees or treeline are not thermometers, they only correlate with temperature, so a higher treeline is not a proof, just a hint.
What wouldn’t be science would be to claim this hint is proof.

rd50

The paper by Nichols presents a detailed discussion of the 1949 paper by Mar regarding soil.
There are two possibilities: soil development vs climatic changes.

Felix

So, not just Cherry Herring any more!

philsalmon

So tree lines agree with isotope reconstructions in both ice cores and ocean sediments. But not the pollen and other bio proxies that OSU have used to iron flat the Holocene.

Guess what? The pollen and other bio proxies record ecosystem regime changes but are cr@p temperature proxies. Shakun, Marcott, Miller etc have of course known this all along.

tty

At least in Northern Europe the pollen evidence agrees very well with ice cores and ocean sediments. The Early Holocene optimum (“den postglaciala värmetiden”) was originally discovered by Scandinavian palynologists more than a hundred years ago.

Rich Davis

More than a hundred years ago? That’s unreliable then. Don’t you know, the past is not what it used to be.

paul courtney

Rich: Yes, unreliable. But don’t you know it gets alot more accurate after CliSci adjustments? And, being the past, it also gets cooler?

Rich Davis

precisely. Only the future is certain. The past is always changing.

Gunga Din

If more than one tree or tree ring was used then it doesn’t count.

They look at tree remnants recently exposed. Then they say that “Evidently, this was the warmth peak of the Holocene, hitherto.”. So they are saying that this is evidence of the peak. But is it? If they wait until the ice recedes a bit further, they might find more tree remnants, meaning that the peak was actually higher.

tty

Actually it is a minimum figure. Since the wood has been found in glacial outwash it must originally have grown at a higher altitude (unless water flowed upwards in the early Holocene).

nw sage

The comment was made that ‘they’ corrected for isostatic uplift due to glacial extinction. It there any reason to assume such isostatic uplift is either uniform or constant when shifting from one continent to another? Are the tectonic plate thicknesses, stiffness and buoyancy (on the mantle) the same?

tty

No it only happens where there has been an icecap, and it has nothing to do with “extinction”. And no it isn’t uniform and it isn’t constant, though it is essentially linear over shorter periods like a few centuries.

In Scandinavia this phenomenon “landhöjningen” has been known for centuries and has been very thoroughly researched. Also how it changes over time is known with fair precision by studying how the (relative) sea-level has changed:

comment image

Relative sea level curve Stockholm area.

And this is what it amounts to today (mm/yr):

http://www.klimatupplysningen.se/wp-content/uploads/2017/08/nkg2005lu_stor.jpg

Stephanie Hawking

Whatever relevance the paper has to mean global temperatures then, the physics is irrefutable: CO2 and other GHGs are causing the global warming now. Nothing else.

paqyfelyc

well, had you wrote, ” the physics is irrefutable: CO2 and other GHGs are causing SOME global warming now” you would had been right, and nobody would complain.
Unfortunately, you used “THE”, implying that no natural variation (or human-caused warming unrelated to GHG, like UHI) occurred.
Which never happened in the whole history, and is utterly unbelievable.
So you are wrong.

Thomas Homer

paqyfelyc: [ well, had you wrote, ” the physics is irrefutable: CO2 and other GHGs are causing SOME global warming now” you would had been right ]

The physics is irrefutable?

The physics of Earth’s gravity causes water to run downhill.
We leverage this physics by generating power from hydro-electric facilities.
The physics is irrefutable.

The difference of sea level between low and high tide in the Bay of Fundy is 50 feet. If ‘water always runs downhill’ is irrefutable physics, how did the water get up to the high tide mark?

tty

That remark shows that you have no idea how tides work. The water is always at the same level in terms of energy. However that level varies relative to the coastline depending on the relative positions of Earth, Moon and Sun.

So yes the water runs ‘downhill’ to the high tide mark (somewhat simplified, since there are dynamic effects due to the coastal configuration, the energy for this comes from slowing down the rotation of the Earth)

Thomas Homer

tty “The water is always at the same level in terms of energy.” ???

– Do you know how waves work?

You seem to have missed the point of my analogy. Water always runs downhill, and CO2 has an immeasurable GHG property, each of those are considered ‘irrefutable physics’. Yet each do not present as ‘irrefutable’ in the real world.

Rich Davis

in other words, they are saying the science is sound, therefore the effect is significant.

The scientific principle of GHGs absorbing infrared may be sound, but the fallacy that trolls like Stephanie and the rest of the CAGW faithful fall into is that this proves that the overall effect is significant, and that the observed temperature change is mostly (or as they sometimes claim, is totally) due to GHGs. They grossly over-simplify the question, and deny the existence of homeostatic processes that offset the theoretical warming. In fact the only science that is sound is that CO2 absorbs IR. The “science” that says that this will induce positive feedback by increasing water vapor is disproven by observation.

CO2 driving global warming is no more valid than the claim that the rooster crows to make the sun come up. CO2 outgasses from the oceans as they warm. CO2 lags temperature changes, it does not cause warming, warming causes increases in CO2 (human activity adds to it a bit, but is not the cause of the warming). Adding roosters doesn’t speed up the sunrise.

Every time we have a hot day, we hear about proof that Climate Change (TM) is killing us, and every time we have a record cold month, it’s *crickets*.

tty

“Do you know how waves work?”

Yes.

comment image?692

Thomas Homer

tty: Since you know how waves work, would you like to qualify your earlier claim?

“The water is always at the same level in terms of energy”

Rich Davis

It would be the same sum of potential energy plus kinetic energy. Potential energy changes as the moon passes overhead (gravitation of the earth offset by gravitation of the moon) and kinetic energy changes with the tidal flows, but the total energy stays the same.

You two are talking past each other. This tide example illustrates the point that when you oversimplify a problem, valid scientific principles tell you that the events that actually happen in the real world are theoretically impossible. Water flows to its lowest potential, but just because that is true, it is wrong to say that the lowest potential is always down hill. The moon is a complication being ignored. Just as the CAGW believers fail to adequately account for clouds.

Thomas Homer

Rich Davis – Thank you – you’ve verbalized in a better way much of what I was trying to illustrate.

There are many forces acting on ocean water including tides, waves, wind, etc. in addition to gravity.

tty

“would you like to qualify your earlier claim?”

No, since we were discussing tides, not waves.

mkelly

paqyfelyc
June 1, 2018 at 4:28 am
well, had you wrote, ” the physics is irrefutable:

Which physics is irrefutable?
1. IR from CO2 hits surface of earth and warms surface.
2. IR intercepted by CO2 and that molecule passes energy onto other molecules in atmosphere.
3. IR is being released from higher in atmosphere by CO2 causing lapse rate to raise surface temperature.

The only way the temperature goes up is if translation velocity of molecules in atmosphere increases and I have yet to see that velocity increase is caused by IR in any of the three.

Stephanie Hawking

Oxford professor Myles Allen has an excellent tutorial here:
http://www.realclimate.org/index.php/archives/2018/04/the-alsup-aftermath/
You can also ask questions.

The tropopause is rising and the stratosphere is cooling. What does that tell you?

Two textbooks from Cambridge University Press. Andrew Dessler: Introduction to Modern Climate Change. John Houghton: Global Warming the complete briefing. I might have recommended them to you already.

MarkW

Fascinating, please demonstrate how you know conclusively that all the things that have caused the climate to change in the past are not operating today.

AGW is not Science

I think you forgot the “/sarc” at the end of your post. Either that, or you are a deluded fool.

Dodgy Geezer

..could a priori mean that summer temperatures were at least 4.2 °C warmer than present around 9,500 years before present. However, glacio-isostatic land uplift by at least 100 m since that time (Möller 1987; Påsse & Anderson 2005) implies that this figure has to be reduced to 3.6 °C higher than present-day levels, i.e. first decades of the 21st century. Evidently, this was the warmth peak of the Holocene, hitherto.”….

This is, of course, raw data which should not be published, as it is the private property of someone.

Once it has been properly corrected, however, you will see that the temperature 9000 years ago was 3.6deg LESS than the present day. Therefore, we are all going to fry unless someone gives me a lot of money….

/sarc

jay white

North of 600 m… So, English isn’t his native language… Give him a break. We know what he’s saying.

North is a synonym for “above”. A bit informal but still valid.

Rich Davis

North is a synonym for up?

We must overcome this septentrionicentristic bias oppressing the peoples of the global south. Down with north privilege! Up with the south pole!

In solidarity with our sistren and brethren down under.
Er, Up above
RD

“North of 600 m… So, English isn’t his native language”
The Swedish author got it right (atop). That text is actually Kenneth Richard, unattributed, displaying his usual accuracy.

nobodysknowledge

What about other latitudes?
“Glaciers on Kilimanjaro’s highest peak, Kibo, are currently regarded as a persistent feature of the Holocene. Here we synthesize all available measurements,
observations, and our understanding of current processes on Kibo – gained from intensive research over the past decade – to formulate an alternative
hypothesis about the age of these ice fields. This suggests a shorter, discontinuous history of the tabular-shaped glaciers on Kibo’s plateau, where typical ‘life
cycles’ of the ice may last only a few hundred years. If life cycles overlap, they are likely the cause of the observed steps in the plateau glaciers. Thus, it is likely
that ice has come and gone repeatedly on Kibo’s summit plateau, throughout the Holocene. Such a cyclicity is supported by lake-derived proxy records.”
https://www.geo.umass.edu/climate/tanzania/pubs/kaser_etal_2010_holocene.pdf

NZ Willy

Look at the vertical scale — not that much in it, all in all.

tty

What vertical scale?

Olavi Vulkko

In Finland Lauri Timonen has lead collector of treeline evidence about past climate. http://lustiag.pp.fi/ Lot of science http://lustiag.pp.fi/suofintr.htm.

Hugs

Mauri Timonen. Those dendro people tend to be quite skeptical, I wonder why?

ES

At Strathcona Fiord on the west central coast of Ellesmere Island (170 km -110 mi) to the south of Eureka Nunavut, Canada, they have found a fossil record of tremendous international scientific significance. These fossils, including plant and animal remains, have provided a unique opportunity for understanding the effect of climatic change through the past 4 or 5 million years on the Arctic environment, and on its flora and fauna.

Pliocene fossils (3-5 million years old): Paleoclimatic reconstruction suggests a mean annual temperature that was 14–19 °C (25–34 °F) warmer than present day.

Eocene fossils (about 50 million years old): These earliest finds include the fossil remains of an alligator. Very notable are the petrified tree stumps, some of which are preserved in their original growth position. The trees show wide growth rings indicating favorable growth conditions.The fossil flora indicates the presence of rich floodplain forests dominated by dawn redwood (Metasequoia glyptostroboides), together with ginkgo (Ginkgo adiantoides), walnut family (Juglans and other Juglandaceae), elms (Ulmus spp.), birch and alder (Betulaceae), and katsura (Cercidiphyllum). Analysis of nearby fossil leaf sites from central Ellesmere Island of the same age indicate that these forests grew under very high rainfall, and can be considered to have represented a polar rainforest.
This lush Eocene ecosystem thrived under a polar light regime. Like today, the region would have seen 24-hour sun in the summer and 24-hour darkness in the winter as it was positioned at almost the same latitude in the Eocene as it is today. Despite an early Eoceneclimate with generally mild frost-free temperatures, the polar light regime likely forced these plants to be deciduous.

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

Tony Banton
Bruce Cobb

That’s not possible. SUVs hadn’t been invented yet.

Harry Twinotter

3-4C warmer post-glacial in the subarctic in one location. Why is this “inconvenient”, it’s not even controversial.

And it was said by the prophets and wise men, ‘The warmists shall claim it’s just one isolated example as they have with every other warm period that damaged their narrative. And in each of those more evidence crept in showing that no, they were not localized or isolated.’ And lo, Harry Twinotter promptly obliged.

Javier

Yet Harry is right. Among specialists this is not controversial. What is controversial is saying that the present is warmer than the Holocene Climatic Optimum.

Harry Twinotter

Javier.

Who said the current global warming is warmer than the optimum? Do you have a reference? I check extraordinary claims.

Javier

Marcott et al., 2013 did. And it had a huge repercussion in the press. There were several cartoons made about riding the global temperature anomaly. One of them illustrates the NOAA article “What’s the hottest Earth has been “lately”?”
https://www.climate.gov/news-features/climate-qa/what%E2%80%99s-hottest-earth-has-been-%E2%80%9Clately%E2%80%9D
Where it is said:
“For most of the past 10,000 years, global average temperature has remained relatively stable and low compared to earlier hothouse conditions in our planet’s history. Now, temperature is among the highest experienced not only in the “recent” past—the past 11,000 years or so, during which modern human civilization developed—but also probably for a much longer period.

Carrie Morrill of the National Climatic Data Center explains, “You’d have to go back to the last interglacial [warm period between ice ages] about 125,000 years ago to find temperatures significantly higher than temperatures of today.””
The article was reviewed by Marcott.

This opinion, dressed as scientific fact, is based on careful proxy selection and incorrect statistics. It is hugely controversial among scientists like Leif Kullman (of Swedish treeline studies), that see the present period as well within Holocene variability.

Harry Twinotter

Good reference, thanks for that. One study. But the study does not say they are sure that current temps are warmer than the optimum. From the abstract: “Temperatures have risen steadily since then, leaving us now with a global temperature higher than those during 90% of the entire Holocene.”

They are hedging because of the uncertainties involved. That is the wise thing to do.

The article does not say highest either, as your quote clearly shows.

Felix

All evidence from every possible source shows that the Holocene Optimum (5 Ka) was warmer than or as warm as the Egyptian Warm Period (4 Ka) and the Minoan WP (3 Ka), while definitely hotter than the Roman WP (2 Ka) and the Medieval WP (1 Ka).

The Modern Warm Period has yet to enjoy the same peak warmth as the Medieval. One can only hope that we do, but that’s not the way to bet.

The Holocene is on the slow path toward the next glaciation, sadly.

Harry Twinotter

“All evidence from every possible source”? If I told you once, I have told you a thousand times, never ever ever exaggerate 🙂

Yep, the good ol’ MWP. It was like a sauna, every possible sources confirms this (not).

Harry Twinotter

davefreer.

Other than your poor attempt to sound funny. The Holocene Climatic Optimum is not an isolated example, there is plenty of evidence for it. So I don’t get your point, if you even have one.