Holocene Climate Change In The Arctic
October 25, 2023
By Paul Homewood
I came across this paper again the other day. It’s from 2016, but still highly relevant:
https://www.sciencedirect.com/science/article/abs/pii/S0277379116300427
It’s quite a powerful study because of its wide geographical coverage, unlike other studies that focus on one particular proxy in one location.
Below is the key graph. It’s measured in SDs, but illustrates how temperatures plunged around 3000 years ago, and notably since the Middle Ages:
Figure 2 also shows the area of the Greenland ice sheet, which reached post ice age minimum about 4000 years ago, and was at a maximum at the end of the Little Ice Age:
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NOT A LOT OF PEOPLE KNOW THAT 
Hells Bells – someone doing proper balanced science. It will get them nowhere – has anyone heard of them recently?
About 10 years ago I gave a presentation, based on the Holocene Interglacial, at a science and technology group meeting . I prefaced my 20 minute bit with a reminder that I was presenting facts (data) as far as we knew them – not my opinion.
It was based mostly on Greenland ice core data and aligned closely to the analysis of this paper (as we would expect). Despite the fact that those present had mostly a science or engineering background I received quite a lot of abuse. It is amazing how the relentless propaganda (and it has got worse since then) bends even those who should be immune to it to its will. Even the Royal Society.
The worst abuse was when I pointed out that we were approaching the cold end of the interglacial, that temperature peaks in the last 8k years have been progressively colder, that the recent “Little Ice Age” appeared to be one of the coldest periods in that 8K years. I finished by saying that “opinion” suggests that at the start of the interglacial the Earth’s human population was less than one million. CO2 had fallen to 180ppm (nothing grows at 150) and that the only certainty was that would come back in the next glacial period. Good luck with that.
I was impressed with the depth and scope of the studies presented in this paper. They covered it all as far as today’s technology: sediments, ice cores, etc. For many decades, pollen/spore studies in bogs have showed the ebb and flow of species with the advance and retreat of ice sheets.
These REAL scientists brought all of their fields together and covered the subject with real truth and scientific evidence.
Kudos to them all.
Hereabouts in central Scotland we’ve a sequence of terminal moraines overlying in discrete areas previous ice-age glacial sediments. Carbon dating the very little bone fragment remains puts it to about mid earlier ice age. Recent studies using coring – espec via pollen analyses – demonstrate, unequivocally, a very rapid glacial readvance ca 12.5-11.5 ya.
I wonder if that was enough to end the previous civilizations?
Rather than the cataclysm type theories (Some of which which sound plausible to me as a lay person).
The interglacial civilisation fantasies were the stuff of Hollywood scriptwriters when I studied Physical Geography as part of my degree in Prehistoric Archaeology. many years ago. Physical Geography should be included in many more course requirements.
Interglacial civilisations have left no physical evidence as far as I know… but I remember strange paragraphs of information from the USSR were common in the cheaper newpapers then.
Sorries.
‘The temperature decrease from the warmest to the coolest portions of the Holocene is 3.0 ± 1.0 °C on average (n = 11 sites).’
I don’t believe we can know to that accuracy.
At least they don’t give digits to the right of the decimal point! 🙂
As Old Met Man correctly points out, the only valid proxies are those that conform historical data. The paper above, fits that criteria, which the ‘simulations’ of Hansen/Mann do not. Such simulations were described by Professor Nancy Cartwright as ‘Simulacrum’; an explanation that appears to fit the facts, but is woefully incomplete. Incomplete usually because of gross simplification to fit the limitations of the mathematical software. The current ‘climate models’, as is clearly shown in postings on the internet, are based on the idea of low level perturbation around an assumed ‘steady state’. This methodology was introduced by Continental mathematians in the late 18th C.
Faced by the extreme difficulty of solving the very plain problems raised by Isaac Newton in his ‘Principia’, they plumped for a simplistic cop-out, the idea of an underlying ‘steady state’ condition around which small perturbations could be assumed, without marked changes in behaviour leading from the underlying non-linearity of the physics. This was recognised in the 1820s, when mathematical physics textbooks cautioned the tyro that the mathematics displayed was only valid for small changes in displacement, velocity and other parameters.
Sadly, as the century progressed, the belief that algebraic methods could be trusted to explain all phenomena, became almost holy writ and it took a new generation of mathematical analysts such as Rayleigh and Poincare to show that the method of ‘small perturbations’ and ‘steady state’ could not encompass all physical behaviour. The ‘classical approach’ was challenged by the discovery of phenomena which it just could not explain, with behaviours that confounded these simplistic algebraic assumptions.
We accept the fact that we cannot predict ‘weather’ for more than a few days, even with the computational power of super computers. Yet, we seem very reluctant to accept that the underlying mathematical assumptions used to program those computers, may themselves be suspect?
A favourite phrase, parroted by the media ‘luvvies’ is of the fear of ‘tipping points’ with no point of return to a stable state. Such points in analysis are only demonstrated by non-linear systems; ‘jumps’ to a new state of equilibrium where some kind of energy balance is restored. These jumps, while inconvenient, are seldom total catastrophes and the human race has suffered many such in the last 5000 years, in some cases having to abandon fledgling experiments in agriculture to return to hunter gatherer subsistance, due to local climatic conditions.
So, I have very serious doubts about our current ability to predict the future, based on what is little better than a ‘simulacrum’. Our history is littered with the failures to acomplish this, from Claudius Ptolemy to Kelvin’s prediction of the age of the earth.
Ref. ‘How the Laws of Physics Lie’ Nancy Cartwright, Clarendon Press, 1983
Not that long ago the IPCC agreed with you, mervhob.
“In sum, a strategy must recognise what is possible. In climate research and modelling, we should recognise that we are dealing with a coupled non-linear chaotic system, and therefore that the long-term prediction of future climate states is not possible.”
So stated the IPCC’s Working Group I: The Scientific Basis, Third Assessment Report (TAR), Chapter 14 (final para., 14.2.2.2), p774.
the area of the Greenland ice sheet, which reached post ice age minimum about 4000 years ago, and was at a maximum at the end of the Little Ice Age
Of course this is where the propagandists step in and assert the LIA ended because steam power from coal burning was invented. In their world the LIA would have continued a lot longer without any human activities intervening, but they can’t explain why there was such a period.
Exactly. The LIA is a discrete event, it started because of something. If it naturally got colder, it’s far more plausible (and Occam’s Razor simple) that it got warmer naturally. I could be convinced we have warmed around the margins, but it remains far more likely that natural variation is large on every scale, from each second to millennia.
The Little Ice Age commenced circa 1280 / 1350 CE as the cosmic dust influx escalated almost vertically within that timeframe [ see Franzen and Cropps Cobalt / REE index peat mire proxy series ] – near absent of any upper scale VEI eruptions evident in the ice core stratigraphy between 1300 – 1343 CE – convergent with the 1280 – 1350 CE Wolf Solar Minimum There was a cluster of higher order VEI eruptions during the timescale 1257 – 1290 CE . It is surely no coincidence there is elevated ammonium and nitrate in the Greenland ice across the first half of the 14th century indicative of meteor activity corroborated by eyewitness records [ the Anjou June 26 , 1321 CE Beta Taurid swarm chronicled in letter correspondence ; Hecker’s 1347 Cyprus earthquake ; the Villani January 1347 quake and the 1347 Paris Medical Faculty report ] . The waning of the LIA coincided with the conjunction of the 1790 – 1830 Dalton Minimum and a cluster of high sulphate and tephra emitting volcanic eruptions between 1809 – 1826 CE while cosmic dust concentrations peaked from 1700 – 1800 CE before abruptly declining after 1810 .
Essentially the Little Ice Age was “book -ended ” and prolonged by the confluence of vulcanism , cosmic [ presumably cometary ] debris incursions and four [ the Wolf , Sporer , Maunder and Dalton ] solar minima episodes. The advent of the Industrial Revolution in the 1830s and 1840s – at that time patchily confined predominantly to Europe and North America – is little more than a ‘selection effect’ blamed on the resurgent warming when in fact it was the dissipation of the three climatic cooling vectors that was responsible .
Look closely at the Greenland ice sheet surface coverage graph and you will see marginally less Greenland ice extent during the first two centuries of the Medieval Climatic Optimum [ 900 – 1100 CE ] when Norse seafarers had established settlements in Iceland and Greenland ,than the Modern Warming Optimum . How have Mike Mann and the Hockeystick aficionados reconciled this dataset that imply the preceding MCO ; Roman and Minoan Optimums were indeed warmer than the MWO . Furthermore, the lowest middle to late Holocene Climatic Optimum ebbing of the Greenland ice sheet coverage – 7000 – 4000 BP – correlates quite well with the PIP 25 Arctic Ocean temperature proxy series displayed on Judith Curry’s 2013 Climate Etc blog article showing the Siberian Sea , Fram Strait and two other Arctic seas were seasonally ice free – and at times ice free year round – variously in those centuries .
Correction : the relevant Judith Curry blog article chart was posted 2017 and the terminology is listed as “mostly ice free ” for the Fram Strait , Laptev Chukchi and East Siberian seas
https://i0.wp.com/judithcurry.com/wp-content/uploads/2017/08/slide7.png?ssl=1
So are the propagandists saying that they would prefer the Little Ice Age to have continued?
Reading about Marx recently I received an impression that when he referred to Past Times he had a very early 19th C view of a past climate Since he wrote in the 1840s it is not surprising . He and Engels were up to date. He was interested more in a golden age of happy peasants , when he thought of it. So it is likely that those who follow his societal views nowadays are tainted by his unconscious background of Germanic thinkers of that period. I may be wrong!!
The reason for the Holocene temperature peak and subsequent decline, is the Earth’s obliquity.
Increased obliquity takes energy from the tropics, and redistributes it to the poles. Thus although the poles were warmer during the Holocene Maximum, the tropics would have been a gnat’s cock cooler. The subsequent cooling temperature tracks the reduction in obliquity. This obliquity cooling will be ending in 500 years or so, as increasing precession takes over.
Note that obliquity is only dominant now because eccentricity is low, which suppresses the action of precession. The lack of a deep precessional Great Winter (Milankovitch Minimum), prevented the normal sudden dive back into another ice age. The same happened 400 kyr ago, when eccentricity was again low, and obliquity more dominant.
Ralph