New Open Access Paper published.
Here is the Abstract and Introduction. The paper is not paywalled.
Complex spatio-temporal structure of the Holocene Thermal Maximum
Nature Communications volume 13, Article number: 5662 (2022) Cite this article
Abstract
Inconsistencies between Holocene climate reconstructions and numerical model simulations question the robustness of climate models and proxy temperature records. Climate reconstructions suggest an early-middle Holocene Thermal Maximum (HTM) followed by gradual cooling, whereas climate models indicate continuous warming. This discrepancy either implies seasonal biases in proxy-based climate reconstructions, or that the climate model sensitivity to forcings and feedbacks needs to be reevaluated. Here, we analyze a global database of Holocene paleotemperature records to investigate the spatiotemporal structure of the HTM. Continental proxy records at mid and high latitudes of the Northern Hemisphere portray a “classic” HTM (8–4 ka). In contrast, marine proxy records from the same latitudes reveal an earlier HTM (11–7ka), while a clear temperature anomaly is missing in the tropics. The results indicate a heterogeneous response to climate forcing and highlight the lack of globally synchronous HTM.
Introduction
Natural climate variability results from multiple forcings and feedbacks with heterogenous spatiotemporal manifestations. Greenhouse gases, volcanic radiative forcing, and solar irradiance apply rather homogeneously across the Earth’s surface, while insolation varies both latitudinally and seasonally. In addition, the climate system response may be amplified or dampened by feedbacks inherent to changes in physiography, albedo, and by variations in oceanic and/or atmospheric circulation that (re)distribute heat across the Earth’s surface. Our understanding of climate processes is limited by the rather short temporal span and heterogenous spatial coverage of instrumental records. Evidence of past climate variability gleaned through the testimony of geological archives thus offers a unique opportunity to contextualize ongoing changes and to assess climate model performance on timescales going beyond the decadal climate variability recorded in the instrumental period.
The temperature at the Earth’s surface responds directly to global radiative forcing and thus provides fundamental insights into the state of the climate system. Over the past decades, quantitative indicators of past temperature (hereafter called “proxies”) based on different types of archives have been used to reconstruct climate variability over a range of timescales. The improvement of both spatial coverage and temporal resolution of temperature proxy records led to the development of regional and global temperature reconstructions, which have allowed the scientific community to highlight the unprecedented nature of anthropogenic climate change across the common era1,2 and the Holocene3,4,5,6. Global temperature reconstructions consistently depict a Holocene Thermal Maximum (HTM) typically ranging between 10 and 5 ka4,5 with a maximal probability centered around 6.45 ka4. The HTM was followed by global cooling until the end of the nineteenth century CE, interrupted by rapid and sustained warming characterizing the industrial era towards the present. Yet, the cooling trend inferred from proxy records, often attributed to declining high northern latitude insolation, cannot be resolved in numerical simulations7. Indeed, in climate models, the simulated global mean temperature is predominantly driven by the ice-sheet extent and atmospheric greenhouse gas concentrations, which in synergy impose continuous warming over the course of the Holocene7.
This discrepancy between proxy data and model simulations, commonly referred to as “The Holocene Temperature Conundrum”7, casts doubt on the conceptual framework underlying temperature proxy interpretation and on climate model skill. For instance, it has been suggested that temperature reconstructions may be seasonally biased7,8 and/or that the global mean value is skewed because of the overrepresentation of northern North Atlantic sea-surface temperature (SST) records5,6,7. However, model-data inconsistencies may equally well result from geographically divergent trends due to sea-ice dynamics9, polar amplification10, insufficient model resolution11, and boundary conditions used in numerical simulations12. Although the HTM has been intensively studied from a global perspective3,4,5,6,7, its spatio-temporal characteristics have received relatively little attention, even though the local and regional trends differ markedly from the globally averaged reconstructions3,13.
In this study, we seek to document the spatiotemporal expression of the HTM in the marine and continental realms to shed light on the forcings and feedbacks underpinning the evolution of Holocene climate9.
Here is the press release from EurekAlert!
An international team of researchers from Germany, the United Kingdom, Switzerland, Canada and France reveal the complexity of temperature trends over the past 12,000 years.
MARUM – CENTER FOR MARINE ENVIRONMENTAL SCIENCES, UNIVERSITY OF BREMEN
CREDIT: COPYRIGHT: VINCENT JOMELLI
In this new study, scientists used the largest available database of past temperature reconstructions extending back 12,000 years to carefully investigate the geographic pattern of temperature change during the Holocene. Olivier Cartapanis and colleagues find that, contrary to previously thought, there is no globally synchronous warm period during the Holocene. Instead, the warmest temperatures are found at different times not only in different regions but also between the ocean and on land. This questions how meaningful comparisons of the global mean temperature between reconstructions and models actually are.
According to the lead author Olivier Cartapanis, “the results challenge the paradigm of a Holocene Thermal Maximum occurring at the same time worldwide”. And, while the warmest temperature was reached between 4,000 and 8,000 years ago in western Europe and northern America, the surface ocean temperature cooled since about 10,000 years ago at mid-high latitudes and remained stable in the tropics. The regional variability in the timing of maximum temperature suggests that high latitude insolation and ice extent played major roles in driving climate changes throughout the Holocene.
Lukas Jonkers, co-author of the study and researcher at the MARUM – Center for Marine Environmental Sciences in Bremen, Germany, says “Because ecosystems and people do not experience the mean temperature of the Earth, but are affected by regional and local changes in climate, models need to get the spatial and temporal patterns of climate change right in order to guide policy makers”. Thus, the new work by Cartapanis and colleagues presents a clear target for climate models as the ability of climate model to reproduce Holocene climate variations in space and time, will increase confidence in their regional projections of future climate change.
MARUM produces fundamental scientific knowledge about the role of the ocean and the ocean floor in the total Earth system. The dynamics of the ocean and the ocean floor significantly impact the entire Earth system through the interaction of geological, physical, biological and chemical processes. These influence both the climate and the global carbon cycle, and create unique biological systems. MARUM is committed to fundamental and unbiased research in the interests of society and the marine environment, and in accordance with the Sustainable Development Goals of the United Nations. It publishes its quality-assured scientific data and makes it publicly available. MARUM informs the public about new discoveries in the marine environment and provides practical knowledge through its dialogue with society. MARUM cooperates with commercial and industrial partners in accordance with its goal of protecting the marine environment.
JOURNAL
Nature Communications
DOI
ARTICLE TITLE
Complex spatio-temporal structure of the Holocene Thermal Maximum
ARTICLE PUBLICATION DATE
3-Oct-2022
To summarise, the climate models are crap.
and who’d have guessed that?
Both the climate models and Mann’s tree ring circus are crap, although the report still fence-sits rather than make a definitive ruling. As well as buying into the whole ‘unprecedented modern warming’ rubbish.
My thoughts exactly. They’re saying that both proxies and models are unreliable and then say the modern warming is unprecedented. That’s a logical fail if there ever was one.
nope.
you need to read harder
Another mosh drive-by shooting.
A drive by moshing?
Mosh has turned into a seagull.
Actually the main claim of this crap “research” brought to you by YouReekAlot! and The Science ™ is that there has never been any globally-synchronous warm period during the Holocene. (You fools!) Which makes the current barely discernable mild warming UNPRECEDENTED!
No HCO, no Egyptian, no Minoan, no Roman, no Medieval Warm Period. How could they be real when The Modelz don’t um, model them? Only the hellscape we are daily struggling to survive has been global in scope. Pray pay no heed to the record lows in Antarctica (weather).
No global Cold periods either! Indeed the supposed “Little Ice Age” likely wasn’t real either. Just a regional North Atlantic event. Our reconstructions are biased dontchaknow by too many reports by white guys on boats in the Atlantic. (No doubt transporting slaves and spreading syphilis to the noble indigenous First Nations).
Don’t you think that native Americans wished that they had a wall once Europeans started showing up on their beaches?
You need to read what happened to the iron nails of Captain Cook’s ship when he showed up at Hawaii in 1778.
My stock market model says that the stock market has doubled over the last year. All those stories in the media about a bear market in the stock market must be fake news. Obviously, since the results from my stock market model are produced by a computer, the model results cannot possibly be wrong. Anybody who says that my stock market model is incorrect is a deplorable denier.
The problem is that the dollar’s purchasing power has been melting like snow in the summer destroying your savings in the process (hidden tax).
MWP?
look you sceptics dont believe 40,000 thermometer readings, why do you trust proxy records of the MWP.
hey look mom, i found some monks diary who says it was warm
there is no direct evidence of a MWP. none
Utterly deranged rambling.
^^^^ 10,000 bingos
Mosh tried to make sense for a couple of days. It hurt too much, so he stopped trying.
Yes, that’s true of course. But I elicited NINE capitalist letterz from the mosh. So I am impressed. True, they didn’t come at the start of a sentence. And we got a dot instead of a squiggly mark on the end of the question, and then he stopped trying on the punctuation.
What can you expect from an English major pretending to be an engineer?
Moshup is just extremely ignorant, he has not a clue of the wealth of historical and archaeological data, many from botanical samples, that support the MWP as fact, not anecdote. He’s worse than Griffy really – Moshup might have the potential to discover the truth if he wasn’t politically blind whereas Griffy has neither the will nor ability to see beyond his own blinkers.
The many problems with those thermometers have been pointed out. Not that you are qualified to comment on the complaints.
Oh and by the way mosh, what’s with the British spelling “sceptics”? Aren’t you from Michigan? Well, knowing you, it might just be another random spelling error.
The thing about the monks isn’t ridiculous at all. There are many written records of the weather and climate in monasteries as well as almanachs which expose some of the lies (especially the “never seen before” ones) which come constantly in the media. Unfortunately, they are quite difficult to find and it’s important to know the year and the region one wants to look at. But to summarize: what we’re seeing now has often happened before during the middle ages where “man-made CO2” certainly wasn’t a problem.
“there is no direct evidence of a MWP. none”
Well, there’s this.
“40,000 thermometer readings”
More to come on those. For a (presumed) non-religious guy, Steve, you live a life of faith.
We believe in the thermometer data. What we object to is the adjustments made to data from well placed stations and the dishonest placement of other stations by lying, cheating, A-holes. Meanwhile you climate wackos continue a fight to have the 1913 record high in Death Valley removed from the records. Now who believes in what again?
@Steven M Mosher
There is. Historical documents about agriculture of certain plants and their Northern appearance as well as tree growth in mountains.
I think you have it backwards. We gave the ‘noble savages’ smallpox as payment for syphilis.
Thank you for the correction
If they attack too hard, the gate keepers will keep the study from being published.
I noticed. Moshup seems to be shoe-horning his biased views into the discussion everywhere he can find a place.
He’s so desperate for attention that he’s willing to make a complete fool out of himself.
The tree ring source/artisan spring inverse square proximity formula needs to be tweaked. The non-fossilized wood from these sources make the best hockey sticks.
No no it’s all the La Ninas and El Ninios and stuff wots messing with the plant food-
La Niña’s Shock Return Suggests Important Details Are Missing in Climate Models (msn.com)
Actually, what this study seems to do more than anything is cast shade on the entire concept of a globally averaged temperature, which the climate models attempt to mimic. Because there is no such thing as a globally averaged temperature – whether during the middle of the Holocene, or now.
What DOES exist is regional and local climates that are determined by a large number of factors, from ocean currents to air masses and prevailing wind directions to topography to adjacency and downwind direction to either oceans or large continental land masses.
Trying to average all of that in a global average temperature is like trying to average camels and parakeets to come up with a horse or a dog average.
☆☆☆☆☆☆☆.
Duane nails it.
That’ll be a first, then.
“what does exist ARE regional and local climates….”
Our climate and weather is fueled, not by an average temperature, but by temperature differences. The heat flows result also in enormous amounts of mechanical energy being generated (from the equator to the poles, and from sea level to the stratosphere). Radiation of heat to space is only part of the story.
actuall it does say the tropic were largely stable and that is the biggest failure in the models, so they agree the models fail. Williis E emergent phenomena.
The Tropics will always be stable. Ocean temperatures do not exceed ~30° without triggering Willis’ Emergent Thunderstorms… a Hard Thermostat that sets an Hard Upper Limit. AND nowhere do (open water) Ocean Temperatures rise above the trigger levels.
The Tropics never cool significantly because they are hammered with SW Solar Radiation daily that drives temperatures upward toward the Trigger Temperatures almost daily.
So… Northern Hemisphere Trends are likely Global Trends since Tropical Trends don’t exist.
To summarise: Well, what we know is that we actually don’t really know at all…
no.
to summarise. the models and proxies disagree, so we dont know which is right
Yes we do. Neither.
Incorrect. The models and proxies used to support CAGW disagree with each other and other data. Obviously those models and proxies should NEVER have been used to determine policy decisions.
We can prove that the models are completely broken.
You conjecture that the proxies have issues.
Probably neither, but Climastrology dogma must not be questioned, so surely the proxy data needs correcting.
mosh metrics:
Disappointing! Two missing capitalist letterz (as to be expected) but also a dot where there should be one of them tadpole marks. Then a miraculous correctly placed tadpole getting our hopes up only to be dashed by the missing apocalypse denoting a contraction and finally no dot at the end. Content-wise? Zero point zero.
I like Javier’s article (much Better) posted here sometime ago—a real scream.
Here is the article—-https://wattsupwiththat.com/2016/09/29/earths-obliquity-and-temperature-over-the-last-20000-years/
Want to question the models? Start here:
The Application of the Dynamic Atmosphere Energy Transport Climate Model (DAET) to Earth’s semi-opaque troposphere.
I have to say I’m heartily sick of hearing “[Whatever is worse etc] Than Previously Thought”. The same old tired emotive tosh every time. And the absolute reliance on models to generate the required level of alarming projections, fear and anxiety reveals their true purpose.
“Natural climate variability results from multiple forcings and feedbacks with heterogenous spatiotemporal manifestations.”
Sounds settled?
Everybody laughed when Rumsfeld uttered those immortal lines about Iraq, but they are more than relevant in the climate scare game.
“There are known knowns, things we know that we know; and there are known unknowns, things that we know we don’t know. But there are also unknown unknowns, things we do not know we don’t know.”
Climate sceantists would do well to take that on board.
Rumsfeld’s analysis is simply the application of a Boston Square with one part missing, namely unknown knowns – that is the things that we used to know, but have now forgotten.
I can assure you from personal experience that a forgetory (the opposite of a memory) is a powerful tool that aids clear thinking.
Yes. The first things that get forgotten, are logical and critical thinking…
Those that laughed were another example of Dunning-Kruger. But with time “unknown unknowns” are now an accepted part of any in depth discussion about complex subjects. He who laughs last laughs longest.
I’ve yet to start laughing, Ben
I would even write climate scenetists….
Good catch, another example of mixing actual (scientific?) data into woke CAGW dissertation. Geologists rely on Sequence Stratigraphy to show the state of H2O, liquid or solid, utilizing sea level/water depth markers, to display relative earth temperature cycles/fluctuations (the part that is gas doesn’t appear to participate in sea level). Proxies are what politicians utilize when they want to be somewhere else the day of an important vote.
The tropics ” changing little” is to be expected, and is no evidence of the lack of a “global” Holocene Climate OPTIMUM” (the historical reference they keep trying to change). The ocean warming showing up before the atmosphere is only shocking if, like today’s pseudo-scientists, you think the tail wags the dog. Shades of “we must get rid of the Medieval Warm Period,” again.
The models showing “continuous warming” shows them to be as deliberately worthless as every iteration of Mann’s “Hockey Stick” reconstruction.
The fact that their first listed climate influence is “greenhouse gases” is the tell that they’re just trying to prop up the bullshit, not move their ‘position’ any closer to reality.
I agree, with your first point particularly. Its very strange that alarmists expend so much effort to demonstrate modern AGW presents differently around the world (current warming is much greater in the north than at the equator, the northern hemisphere is warming more than the southern hemisphere, etc.) but then say that past warming events were nothing burgers because they were not globally consistent. How do they get away with claiming the bar for past warming events is a uniform global signal but then drop it for current warming? Pure failure of logic.
“Shades of “we must get rid of the Medieval Warm Period,” again.”
That’s what stuck out to me as being the purpose of this study.
Mixing high-resolution thermometer results with low level-proxies to prove the modern warming period is unprecedented. Same old shit.
The fact that we know that animals and plants that only are found in low latitudes now, were once endemic at the poles, should be a tell that it is normal for the poles to warm more rapidly than the tropics. That suggests that high latitudes are a better predictor of global average temperatures than the tropics, and proxies from high latitudes better record variance with time.
The only good climate model is a dead climate model.
The trouble is they’re not dead climate models, they’re zombie climate models
As long as climate modelers use CO2 as a basis for climate change, the models will remain wrong. CO2 doesn’t control the climate, as much as warmunists would like it to. Some things are taken as fact, even though it can be shown that those things are not fact. Co2 is one of them.
Time to have a safe CO2 level. Say about 1000ppm?
The Guardian is quite emphatic on the matter: The safe level, they say, is 350ppm
“In submarines, higher CO2 concentrations are permitted, usually 5000- 7000 ppm. “
https://www.irbnet.de/daten/iconda/CIB7571.pdf
People tend to think that the greens… they’re just misanthropic, but they are also botanophobic; save the animals (cuddly and sweet), kill the plants. Bloody weeds.
900ppm is the optimum for photosynthesis I believe
When I worked in a wholesale houseplant greenhouse, we kept it at 1200 ppm. In my (6) years in submarines, Co2 got high enough that we had trouble breathing. They have what are called ‘Co2 scrubbers’ which remove Co2 from the air, and oxygen tanks to bleed into the sub atmosphere. You can’t do those things while at battle stations because of the noise created.
The natural CO2 cycle is supposed to be CO2 added via volcanoes and the mid ocean ridges….and CO2 removed by the monsoon rains on he Himalayas?
Most real scientists have been well aware of how complex climate is.
It’s only the so called climate scientists who have been trying to over simplify reality so that it can be made to better match their broken models.
They’ve been trying to over simplify reality because of their overly simplistic, mickey-mouse degree teaching. To paraphrase someone or other – when all you teach is peanuts, you’ll get monkeys!
Boy, are those authors going to get it.
I’ll say it again…
The biggest problem with computer models is getting them to match-up to reality.
I thought the problem was trying to get reality to match-up with the models?
That’s what the news media are for.
No, that’s what girdles are for.
The past data is 100% predictable as is any data series and can be fitted by an infinite number of models, of which few, if any, have any predictive value.
Unless the precise physical and mathematical laws underlying the data are unknown, any model based only on fitting to past data is bunk.
This is why models as used in engineering work. They are built from the ground up using well established physical laws and proven mathematical techniques.
This is also why stock market and climate models don’t work, they are built using curve fitting statistics, guess work, misdirection and truly impressive hand waving with no understanding of the underlying processes. This gives them zero predictive value while still being able to pass back testing, because back testing only measures the fit to past data, not the quality of a prediction.
A simple example is fitting a model to a sequence of coin tosses. By using sufficient parameters, the sequence can be precisely duplicated using a model, yet be completely incapable of predicting the next toss.
many completely valid models produce probability distributions that do match reality over time. Many process, such as coin tosses, cannot be controlled so as to know the next outcome. That is not to say climate models have that kind of predictive power.
For the kind of precision required for climate modelling. 1.5 degrees Kelvin / 315 degrees Kelvin implies a precision of less than 0.5%. For that kind of modelling precision, there has to be very well defined relations between all the different parameters. None of the parameters used in climate models come within even a few magnitudes of that kind of precision.
Whether model outputs are better or not: to even suggest that “policy makers” can really have an impact on climate is per se ridiculous. The best mankind can do is maybe mitigate some of the consequences, if there are any locally, if there’s any money left after all this useless and wreckless spending… I suppose it hurts the ego of policy makers to have to admit that they’re powerless, and prefer throwing our money out the window pretending they’re doing something real.
Interesting.
Highlighting Regional Trends in the Climate Models.
All of the Models are in wild disagreement regionally (wide differences)… and none are correct regionally everywhere. So, all of the Models fail to depict what is happening Regionally…and therefore Globally. The Models best at Global Averages are still wrong almost everywhere Regionally. You don’t get to average inaccuracies to arrive at the Truth.
Low skill regionally means that there is NO SKILL Globally… for ANY of the Models.
The Models as a group are an indefensible disaster.
The Models disagree… so only a few could be correct. Yet they routinely AVERAGE the Worst with the Best and call that AVERAGE the likely truth!! Nowhere else in Science is such a travesty of logic allowed…WITHOUT BEING LAUGHED into obscurity.
A recent study of UN IPCC CliSciFi CMIP6 models shows that the models having medium to high ECS values cannot replicate history (hindcast). Low ECS models get closer. Additionally, pretty much all of them have the non-existent tropospheric hot spot to greater or lesser extents. And “hotter” non-existent hot spot results in higher ECSs.
UN IPCC CliSciFi climate models are not sufficient to fundamentally alter our society, economy and energy systems. Everybody involved in the climate scam agree (openly or not) that the goal is to get rid of free market economic systems and replace them with socialism. Crony capitalism is used to get the greedy on board.
An excellent article/paper. It is the period 12,000 to 6,000 years that is the most fascinating. This is where the ice sheets are starting to retreat, The sea level is rising along with 2 advances and retreats during this period. At first glance, the data reflected in the paper does not correlate with these well-documented geological events.
I have seen the post-glacial landscapes in Europe, the UK, the USA (the Yukon is spectacular in this regard), and China. The accompanying loess deposits are extraordinarily widespread. Glacial tills on the banks of the Thames and the list goes on. Alluvial gold mines south easterly of Chicago left over from the last terminal moraine.
So this paper does raise the most important question of all. What is the driver for the 140 m change in sea level? And is a correlation possible with these geological events.