By P Gosselin
Grok AI generated image.
Hans-Joachim Dammschneider has written a book about the climate history of the southern Harz region. In the historical weather data, he discovered climatic fluctuations that, according to the Intergovernmental Panel on Climate Change (IPCC), should not exist.
Long before industrial CO2 accumulated in the atmosphere, there were already alternating warm and cold phases.
Here is the book description:
The so-called Medieval Warm Period (MWP) has been the subject of scientific debate for years. It is not so much a question of whether this warm period actually took place in Europe, but rather how it took place. Was it a local phenomenon that was limited in time and predominantly restricted to Europe, or was it a period of intense climatic change that also had a global impact?
One thing is certain: from around 950 AD, there was a rise in temperature in Germany lasting at least 300 years, which resulted in a marked warm phase favorable to agriculture and life. However, from the beginning of the 14th century at the latest, this period was replaced by a relatively rapid drop in temperature and climatic turbulence in the direction of the so-called Little Ice Age.
In the early reports, the IPCC (1990, AR1) still devoted relatively much attention to the MWP. Over the years, however, this focus diminished, and in the most recent assessment (2021, AR6) little space was given to the Medieval Warm Period. Studies often even question whether it was a global phenomenon. However, a mapping of the available scientific publications (as of 2022) initiated by S. Lüning shows that the Warm Period certainly left evidence across continents.
From the perspective of natural and cultural history, many accounts show that Germany was in a phase of intense cultural and economic growth from around 1000 AD. This period is characterized by the founding of numerous towns, the expansion of agricultural land and strong population growth. Forests were cleared, building methods influenced, and rising temperatures and the resulting positive agricultural economy contributed to prosperity.
Of course, there were no scientific methods for recording the weather, but modern climate research uses so-called “proxies” to derive the climate parameters of the time. For example, the cultivation of figs north of Cologne, successful wine production as far as Schleswig-Holstein and (overall) the PFISTER index resulting from numerous features indicate a longer phase of mild temperatures and favorable climatic conditions. Climate-numerical backward simulations basically confirm this ‘warm period’.
Historically, such periods were often periods in which life flourished – an idea that plays a rather ambivalent role in the climate debate for the 21st century.
The example of Walkenried Monastery and the southern Harz monastery landscape shows the solid consequences of the MWP: the reclamation of swampy areas, the development of the Upper Harz water management system, the promotion of mining and the intensive use of wood for construction and energy purposes are just a few examples.
However, this phase of monastic prosperity between 1130 and 1300 AD was apparently brought to an end by a rapid drop in temperature. The onset of the ‘Little Ice Age’ brought very uncomfortable weather conditions that lasted until the end of the 18th century. As early as the beginning of the 14th century, the country was hit by destructive rainfall and floods (“Schluchtenreisen” / Magdalenenflut), failed harvests followed intense droughts (Dante anomaly) and devastating plagues with millions of deaths in epidemics partly destroyed social structures. These instabilities and hardships, which were not least determined/induced by the climate, certainly had devastating effects on the livelihoods of the monasteries in the southern Harz region. They led to considerable internal crises (including the loss of converts and lay brothers) and ultimately the end of the Walkenried monastic ‘group’ (with the abandonment of large areas of the Harz ore mining industry) in the 15th century.
If this was the case, what overarching climatic processes contributed to this? It can be assumed that, in addition to temperatures, other factors such as the duration of sunshine also played an important role in the living conditions: The sun indeed seems to have been ‘the’ factor of the MWP, whereas CO2 is that of modern times … .
Recent analyses and the AMO (Atlantic Multidecadal Oscillation) index, which can be traced back to 900 AD, indicate that cyclical SST (Sea Surface Temperature) energy influences from the Atlantic could have significantly influenced cloud cover and thus sunshine duration and temperatures in Europe. These interactions were also important for the southern Harz and Walkenried. Can evaluations of current climatic processes indirectly allow conclusions to be drawn about past physical and social changes with associated phases of ascent and descent between 1000 and 1400 AD?
The present study examines these questions and attempts to draw conclusions for the interactions of the medieval climate from large-scale processes of potential ‘teleconnections’ and oceanic cycles. The book is intended, among other things, as a sequence of steps that helps to better understand the complex interrelationships of medieval climate change. It shows which ‘natural’ parameters could have contributed to the rise and fall of Walkenried Monastery.”
Hans-J. Dammschneider (2025)
Klimageschichte der Südharzer Klosterlandschaft – Kloster Walkenried
ISBN 9783759779878, 106 pages, Hamburg/Norderstedt 2025
Order at AMAZON or all bookshops
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
What tickles me the most about this is that society is wealthy enough that someone can write a book on such a very narrow topic, and that we can read about it thousands of miles away. About the only remaining tickle would be to buy the Kindle eBook and have it automatically (and reasonably correctly) translated to English so I could actually read it.
I like progress.
Here’s the publisher’s summary, in English:
[ eBook is for: 5.49 € VAT included.immediately available as download; now what about automatic translation? — next ]
——————————
Climate history of the South Harz monastery landscape — Walkenried Monastery
Hans-J. Dammschneider
The author is the founder and director of the Institute for Hydrography, Geoecology and Climate Sciences (IFHGK).
Website: http://www.ifhgk.org
Volume 16: Series of the Institute for Hydrography, Geoecology and Climate Sciences
Nature & Environment
Paperback
114 pages
ISBN-13: 9783759779878
Publisher: BoD – Books on Demand
Release date: December 11, 2024
Language: German
Tags: climate change, Walkenried Monastery, history, Harz, Middle Ages
The rise and fall of Walkenried Monastery occurred between 1130 and 1430 AD, a period of approximately 300 years. During this period of history, not only did the monastery noticeably rise, but average temperatures also climbed significantly: between 1130 and 1230, by approximately +0.3 °C per 100 years. However, over the next 150 years, these pleasant air temperatures fell again by 0.6 degrees C (-0.4 °C per 100 years).
Of course, not only these temperatures were important for living conditions, but also the duration of sunshine (especially for plant growth and thus harvests). As the so-called AMO index values, which can be traced back to the year 900AD, show, the latent SST energy quantities cyclically penetrating Europe from the Atlantic region with the westerly wind drift have a significant influence on cloud cover, thus on sunshine duration, and accordingly on air temperatures, not only in Germany as a whole, but of course also in the South Harz monastic landscape and Walkenried itself.
Monastic economic life from 1200 onwards may have been dominated by mining, but the basis for survival was the availability of food. This food had to be not only continuous, but above all quantitatively sufficient to feed a rapidly growing population at that time. Negative climatic changes, which apparently began from 1300 onwards, had considerable consequences here, including for Walkenried Monastery. The so-called ‘Great Hunger’ between 1315 and 1322, and above all the Magdalene Flood in 1342, literally destroyed Germany’s food supply on a significant scale. This disruption, certainly perceived as a ‘shock’, is not documented for Walkenried Abbey. Why? Because it didn’t affect Walkenried at all? That’s rather unlikely.
That Walkenried Abbey experienced a marked decline over the course of the 14th century and was even increasingly marginalized from 1500 onwards is, however, hardly surprising, given the general climatic conditions (and the agricultural and economic system at the time, which was largely powerless against the forces of nature).
The wars that subsequently affected Walkenried in the 15th century certainly met with a weakened population and a likely weakened monastery overall.
It is interesting what counts as “significant”. For example it states above that:
”average temperatures also climbed significantly: between 1130 and 1230, by approximately +0.3 °C per 100 years.”
but currently temperatures are 1.5 degrees above the 1900 levels which is 5 times the significant increase of the medieval warm period and nobody here seems to think that it is significant. The rate of temperature rise is also about 5 times faster than earlier rates but again this isn’t “significant”…
There is a massive number of proxies from all over the world that show MWP was warmer than now.
We also have no idea what the actual temperature was in 1900…
… so there is no way of saying it is 1.5C warmer now than in 1900….
Again if we don’t know what the temperature was in 1900 how on earth do we know that the medieval warm period was warmer than now?
Can you say which years we know the temperature for and which we don’t? I am very curious to know.
You obviously don’t understand basic historic and biological proxies, do you. !
Higher tree lines, artefacts under glaciers, terminal moraines, biological fingerprints, lake sediments etc etc etc
How much warmer must it have been for actual trees to have grown where there are no glaciers? It takes long periods of warmth for large stands of trees to grow.
Now.. show us where temperatures were measured in 1900.. and how they had any real idea what the global temperature was.
And how do you go from a set of localised proxies all of which have large intrinsic errors both in time and in absolute value to a global estimate of the temperature? What is the error in global temperature from a set of tree lines in the alps for example? And then compare that to the estimate of the global temperature today from satellite measurements? Which would you put more true in?
You get from localized proxies to global temperatures the same way you get from localized thermometers to global temperatures.
There are proxies all over the world that show the MWP was warmer than today.
Oh nonsense! As izzy will tell you, it was a regional phenomenon. It only affected the earth region as far as we know.
This is a ridiculous line of argument,
Here you are pounding the table on numbers from what everyone admits are lousy proxies. its like nothing matters except adherence to some magical arbitrary set of numbers that have some sort of Cosmic Perfection that was idealized in some time other than the one we are in.
The proper look is towards Human Flourishing with respect to the Climate that civilization is in. From both the anecdotal and empirical evidence of human flourishing, whether it was promoted by monastery achievements, advances in banking, lack of wars and viral epidemics, etc. all amounts to elements, along with the prevailing Climate in terms of human flourishing.
There are a lot of lessons to take away from this. Most important, is that Climate plays a small role in view of the absolute damage that is caused by low trust societies, hostile and corrupt governments, Muslim invasions, and plagues.
Which means it is highly inverted when whining about forecasting deviation from some arbitrary number of imperceptible precision over long periods of speculated time to have that perseveration on the immaterial to dictate large scale attacks on human flourishing (ie. energy destruction, adverse agricultural regulations, social destructive policies, etc.)
“How much warmer must it have been for actual trees to have grown where there are now glaciers and ice.?”
You FAILED to give an answer.
And yes, treelines significantly higher up mountains than today does show it was warmer, as do many other proxies from around the world.
You can also look at migration patterns across northern Euroasia as the MWP ended and the Little Ice Age began. Agricultural production declined, forcing massive movement south. The Vikings stopped raiding southern countries because their ports remained frozen. In Asia, Mongols conquered China and the Moghuls conquered India.
Folks didn’t do “global temperature” in 1900 because back then, folks were realist, practical people who had no time for frivolous, indulgent, bullshit pursuits.
“Again if we don’t know what the temperature was in 1900 how on earth do we know that the medieval warm period was warmer than now?”
Agriculture.
What grew in the Medieval warm period that can’t grow now because it’s too cold?
Surely there was agriculture in 1900 so it should be possible to use the same proxies to work out what the temperature was then compared to 1000AD?
Using what grew where is very imprecise since varieties change as do preferences. There are now vineyards further north in Scotland than there ever was in previous centuries. Is this evidence of global warming or just that the Scots have developed a taste for wine?
Since we really don’t have good data for much more than a century- why should we panic while screaming that the world is burning up (Guteres)and the oceans are boiling (Gore)? If the panic is due to the fact that it’s not a perfect planet- best to get used to it. 🙂
IW turns the statistical null hypothesis on its head. He basically believes the hypothesis (I’m not calling it a ‘theory”) that global warming is real, it’s manmade and caused by CO2, and that an apocalypse is currently underway, AND that it is not his responsibility to prove it is correct but everyone else’s responsibility to prove it isn’t. That’s not science, that’s religion.
This ^
I am just bemused by the people who simultaneously believe that (a) we have no idea about past temperatures because of measurements inaccuracies etc and also that (b) that there were times in the past such as the Medieval Warm period that were significantly warmer than today. The two statements are logically inconsistent yet that doesn’t seem to worry most people here.
Yep!!!!!
You were the one who told us Covid started from a pangolin…lol
What a twonk!
Bemused, certainly. No, they’re not logically inconsistent. You’re trying to create a straw man false choice by assuming apples and footballs are the same thing. Trees being uncovered by melting glaciers mean that the glaciers melted in the past and the climate was warmer back then, and for long enough for trees and forests to grow. If you can’t figure out the significance of this, then not worth explaining further.
The lack of comprehension is astounding. I don’t even believe an explanation is worth while.
It’s a pretty nearly perfect planet, just the same. Just a few annoying alarmists we have to ignore and as a partial compensation we get to ridicule them and get some laughs.
There is NO CLIMATE EMERGENCY!
If we don’t know what the temperature was in 1900 how on earth do we know that the medieval warm period wasn’t warmer than now?
Again if we don’t know what the temperature was in 1900 how on earth do we know that the medieval warm period was warmer than now?
How about the abundant historical evidence for higher temperatures (e.g. cultivation of figs in Cologne and vines in Schleswig-Holstein)?
The global average of a set of homogenised, heavily adjusted averages being 1.5 units higher than a global average of a set of homogenised, heavily adjusted averages from a century ago is functionally meaningless.
But the medieval warm period is real and significant despite there being considerable less evidence for it than there is for warming over the past century?
“But the medieval warm period is real and significant”
Yes, and warmer than now. Large amount of evidence from around the globe shows that.
Current evidence of warming is based heavily on totally unfit-for-purpose surface stations, and fabricated, model-filled data and agenda-based “adjustments”.
There is no real evidence that human CO2 has cause any warming at all.
Certainly can’t use the hodge-podge of highly suspect surface fabrications.
And there is no evidence of CO2 warming in the satellite data.
There has been no warming over the past century. It’s not any warmer today than it was in the recent past, according to the written temperature records.
Your bogus, bastardized Hockey Stick charts don’t tell the truth about the past temperatures. Instead, they distort the temperature profile for political purposes.
And what do you make of the UAH temperature record from satellites? Every month they post the updated temperature here and it currently shows warming of 0.15 degrees per decade. Does that count as warming over the past century?
The UAH data shows warming ONLY at major El Nino events.
There is no evidence of any human-caused warming in the UAH data…. None whatsoever.
UAH starts at a dip in temperatures, from the coldest period since the 1930s warm period… The bottom of the AMO cycle.
Tom is correct…. unadjusted and uncorrupted surface data from places around the world shows the 1930’s was similar in temperature to the around 2000.
One of the few long term surface stations that has not been corrupted by urban effects etc is Valentia. It clearly shows that the decade of the 1930s has a warmer average temperature than any other decade. (blue markers)
No just since 1978 dummy!
The MWP is indeed real and significant. The evidence for it is now overwhelming.
Why do you prefer to argue on the basis of fictitious, adjusted temperature averages rather than on physical evidence?
The evidence for the former is not manipulated to hell and back. The evidence for the latter is largely fiction.
Tell us that this region was warmer 1000 and 2000 ago years for centuries but the rest of the planet remained cooler than it is today. Go on Walton, tell us that….
Your comparison of made-up, meaningless current averages to made-up, meaningless historical averages just goes right over his head.
Partly because his head is deep in the trough ?
😉
It’s significant in a positive way. 🙂
if it ain’t negative and all man’s fault he doesn’t want to hear it.
And humanity is thriving
That’s only true if the current temperatures are accurate, which they aren’t.
Sure it’s significant izzy. We are so blessed by this period of life-giving warmth. It might even prove to be a beneficial side effect of that other incredible blessing—fossil fuels. But that’s just a hopeful conjecture.
The defenders of the Hockey Stick will tell you that, just as the LIA was “regional”, the MWP was also “regional”. Climate was flat for 2000 years. For 2000 years, everything was great, with no droughts, floods, famines, Black Death, or Dust Bowl anywhere.
Obviously it was. That is why they want us to return to that level of technology…
Well they can be the first to lead by “good”example, either that or jump of the Eiffel Tower…either way is fine by me.
After that I might consider to do the same or have a nice cold beer to celebrate their stupidity – guess my choice lol.
Very nice.
“ climatic fluctuations that, according to the Intergovernmental Panel on Climate Change (IPCC), should not exist”
Just untrue. A complete strawman. Just because adding CO2 causes warming doesn’t mean you can’t have warming without adding CO2.
The AR4 devoted a Box (6.4 ) to the MWP. It said:
“The evidence currently available indicates that NH mean temperatures during medieval times (950–1100) were indeed warm in a 2-kyr context and even warmer in relation to the less sparse but still limited evidence of widespread average cool conditions in the 17th century (Osborn and Briff a, 2006). However, the evidence is not suffi cient to support a conclusion that hemispheric mean temperatures were as warm, or the extent of warm regions as expansive, as those in the 20th century as a whole, during any period in medieval times (Jones et al., 2001; Bradley et al., 2003a,b; Osborn and Briff a, 2006)”
AR4? Seriously?
What was said in AR5? AR6?
Each AR tries to say new things. If there is nothing new to say, they don’t. It has been covered.
Each one tries to say the same thing in ever more dramatic language of doom, and anything contrary, or that has been claimed in previous renditions, that is inconvenient or embarrassing, is ignored or downplayed.
That is an utter and total outright lie sir.
The purpose of the AR is to provide an assessment of the current climate with informed opinion as to the future climate in the context of the past climate. There can be no informed decisions made by political leaders if the past is simply ignored.
How do we decide if it is getting warmer? By comparing to the past.
How do we decide if hurricanes, droughts, floods or wildfires are getting worse or not? By comparing to the past.
How do we decide if crop yields are getting worse or better? By comparing to the past.
So AR5 and AR6 just left some of the past out, and provide recommendations to key decision makers on a global basis, and your excuse is that it wasn’t new? Well golly why don’t we just erase all the weather data we have and just make decisions on this year’s data? Look we have one year of data and our trend is zero.
Of all the outright BS comments you’ve ever made on this site, this one is the single most absurd, egregious twisting of facts, horror of a comment I can recall. You’ve pissed me off before Mr Stokes but this is a bridge too far. Screw you, you’re nothing but the paid troll you’re so often accused of being. You found your little AR4 reference and published it here in less than an hour. Soros must be paying you well.
Not to mention that there is in fact plenty of evidence that the MWP existed all around the world. The excuse usually thrown back in my face by disingenuous trolls is “well they weren’t contiguous”. Excuse me, why would anyone expect them to be? With all the variability in the climate you expect a warm pulse to arrive everywhere at the exact same time? That is patently absurd. If the MWP was not in fact a global phenomenon, then why have these warm pulses since disappeared from our climate? You’re left arguing that they were natural, but local, but all started and stopped in roughly the same time period and similar behaviour since then has not occurred. Occum would laugh as he sliced through your blather with his Razor.
You need to go away Nick. You’ve discredited yourself to the point where I will no longer bother reading your comments. There was a time when you brought a nugget of truth to the discussion, but for the most part you just drag discussions off course, the very definition of a troll. This time you’ve gone too far.
Your excuse isn’t an excuse it is an outright misrepresentation of the facts requiring that we now rewrite that popular saying:
There are lies, d*amn lies, statistics and Nokeisms.
From the very first para of the AR6:
“The report builds upon the 2013 Working Group I contribution to the IPCC’s Fifth Assessment Report (AR5) and the 2018–2019 IPCC Special Reports of the AR6 cycle and incorporates subsequent new evidence from climate science.”
Doesn’t fly Nick. Of COURSE it builds on previous work, how could it not? Per your own quote, it incorporates subsequent new evidence. You can’t incorporate new evidence into existing evidence if you leave out the existing evidence.
The IPCC is lying by omission and you sir, are just lying.
Of course it says that. It was written by politicians for policy makers.
AR4 said 1 sigma certainty, AR5 said 2 sigma certainty, AR6 said 3 sigma certainty. You can predict what AR7 will say.
So sayeth the tree rings. With divergence problems. As their one reference.
Divergence affects results after 1960 in some regions only.
But the point is that the IPCC is clearly saying that NH was warmer in the MWP. Nothing in this new book is inconsistent with that.
“NH was warmer in the MWP”….
Thanks Nick.
SH was also warmer than now during the MWP.
Divergence proves that tree rings cant tell whether the trees they came from were from a warmer climate than today.
Divergence, whenever it occurs, regardless of region, reduces the value of the data. It means that the assumptions are questionable. Why else would they need to hide it?
Nick,
the real point is that it was benefitial to the population at that time where the subsequent cooling was devastating.
This is contrary to the alarmist view that warmer is worse.
Well, the point stated was that the IPCC said such variations did not exist. And that is laughably false.
No-one disputes trhat people in cold places may benefit from some warming.
“No-one disputes that people in cold places may benefit from some warming”. You should come to Britain where the media and the government insist that global warming will be catastrophic for the UK. Even more insanely, we currently have a Scottish government which claims that Scotland is too warm.
And Canada ! Which is even more bizarre !
Oh no, than why is there a so called climate crisis?
Not everyone lives in cold places.
Aren’t we told, the climate crisis is a global problem? 😁
But IF there is any CO2 warming, it will be cold places that get warmer.
That is the very opposite of a crisis.. it is highly beneficial…
Just like the small rise since the LIA has been massively beneficial for all life on Earth, especially when combined with a CO2 level that is now above plant subsistence level.
“Not everyone lives in cold places.”
No, VAST numbers of people CHOOSE to live in warmer places.
Like the central part of Victoria, for instance.
except today the MIL sends us a video showing it”s snowing like mad in URAL, whereas here in sunny France it’s 25C.
Tell me now which is the nicer place to live in and which has already blossom and masses of beautiful flowers!??
EXCEPT in summer Ural can be an easy +35C and little different in FRANCE.
Stokes is nuts, just like that Millipede bloke who can’t figure out he’s going down the same path as Spain+Portugal today 28-04-25.
They want to grenade their once reliable grid electricity supplies and then claim they’re trying to “save the friggin planet”!!
M.Mann & Hockeystick, you remember?😂😁
No one?
You may have missed the entire government of Canada (that happens a lot).
Who gives a stuff what AR4, a piece of fabricated political activist propaganda pap, has to say.
Meaningless. !!
There are large amounts of evidence from all around the world that the MWP was warmer than now.
Here’s a new on from the Antarctic.
New Study: Plant Remains Embedded In A Modern Glacier Evidence A Warmer Antarctica 1000 Years Ago
Must have been ”regional”.
“Just because adding CO2 causes warming “
Do you have any measured evidence for that ??
For instance… how much CO2 caused warming has there been in the last 45 years?
Good questions!
Nick doesn’t have the answers.
Nobody has those answers.
The real question is how much warming should be attributed to CO2, and how much is due to natural climate variations?
AFAIK, there is no reliable answer to the above, in which case the next question is how can we justify a policy as extreme as net-zero, without any understanding of what effect, if any, it’ll have on the climate?
The answer to that question should be pretty obvious.
“The real question is how much warming should be attributed to CO2, and how much is due to natural climate variations?”
That is exactly the question, and you are correct that there is no reliable answer, even after all these decades of trying to figure it out.
People who claim to know the level of CO2 warming are fooling themselves and are assuming too much.
But, but, but CO2 is the “control knob.”
/sarc
Crop growth not withstanding. LOL
“It only warmed in one spot” nothing to see here. 😉
For 300 years, while nothing was happening anywhere else. yeah,tell it to the hand…
Nice to see that you believe the work of the IPCC and not in other published science where the MWP is shown it was global.
Nick only believes official, government-sanctioned propaga…oops, studies and reports. If it ain’t government funded it ain’t science.
Yes it did … back in 2007.
.
The IPCC uses more subtle means than explicitly writing something like :
“We have banned all mentions of the MWP and LIA, and flattened them out of all graphs.”
Instead they chose to “prominently display” footnote (c) in Cross-Chapter Box 2.1, “Paleoclimate Reference Periods in the Assessment Report”, on page 295 of the AR6 WG-I assessment report (final version, May 2022) :
A copy of panel (a) of Figure 2.11, “Earth’s surface temperature history with key findings annotated within each panel”, which can be found on page 316, is attached below.
The end result of the IPCC’s “improved climate reconstructions at decadal scale” on the MWP and LIA can be seen in the green lines of the middle section, “(ii) 1000–1900 CE, 10-year smooth”.
“Therefore, the dates of events within these two roughly defined periods are stated explicitly when possible.”
And rightly so. An objection that I frequently make to posts which show MWP’s cropping up everywhere is that the time periods don’t overlap. People don’t seem to think it matters, but at the very lest it makes it hard to answer “when was the MWP”? The AR6 is saying that if you can’t define the timing of a global MWP, better just give the more precise local timings.
But another key problem with the lack of synchrony is that when you try to take a global average of peaks that do not coincide, nothing much shows. Hence the diagram you post.
The global issue is a red herring here. The author’s claim is that the observation of warmth in Germany contradicts the IPCC. Nonsense! The IPCC says that warmth happened.
“The global issue is a red herring here”
Only person throwing red herrings is you, Nick..
There is evidence from all around the globe that the MWP was warmer than now.”
Yeah, kinda the general problem with averages (yes, I edited out the superficial information to get to the main point0.
Yep. A man with his head in the freezer and his feet in the oven is on average quite comfortable.
Does it matter? If it’s as warm today in some regions than it was in the MWP, then at the very least it’s not particularly out of the ordinary or catastrophic is it.
Where it matters is that the GCMs can’t reproduce it for long term change at least regionally if not globally and that proves the GCMs are incapable of reproducing the earth’s climate.
(Jones et al., 2001; Bradley et al., 2003a,b; Osborn and Briff a, 2006)
Famed for hockey sticks, Climategate, lack of transparency, and other abuses of science. Invoking some limited and inappropriate tree ring sorcery does not erase what historical accounts clearly demonstrate.
The IPCC was created for only one purpose: to politically force the acceptance of the theme of human-caused warming due to carbon dioxide. That is its null hypothesis. It is by mandate restricted from considering the alternative.
No one really knows why it warmed and cooled in the past, and to insist that those processes are insufficient or absent at the present time is complete fabrication.
We know from contemporary accounts that glacial ice advanced threateningly and ruinously during the Little Ice Age, devouring forests, fields, and entire villages.
We know that retreating ice today reveals those forests, along with artifacts and remains suggesting trade routes and other human activity only possible in warmer climes than today.
We have accounts of agricultural production in places where, even now, it remains impossible.
We have a bout of cathedral building that could only have been possible during times of pronounced prosperity, which ended as productivity linked to a warmer climate collapsed.
There is absolutely no evidence that CO2 at the concentrations under consideration is or ever has been a determining influence on climate. There is a vast body of evidence that the climate has changed dramatically without any help from us. And all evidence insists that in general cooler is worse than warmer during the period of human existence, and indeed for the existence of life itself.
Now Nick is trying to deny that the Hockey Stick ever existed.
Lol.
Bullshit pure and simple.
“The sun indeed seems to have been ‘the’ factor of the MWP, whereas CO2 is that of modern times”
Uh, no. CO2 has been CLAIMED to be the factor of today’s warm-biased temperature record “warming”. And yet CO2 has never been shown to have affected temperatures any time, let alone now. And that’s because it isn’t a control knob on our climate, or at least not in any way an important one. The sun and oceans are orders of magnitude more powerful factors.
For that we have the magic ‘attribution’ in which x (Co2) is claimed to have … effect which they then cannot provide evidence for but insist on it just the same because of, well The Science which is apparently ‘overwhelming’. Sarc remark..🙂
IF, as hypothesised, carbon dioxide levels lag temperature by very approximately 1000 years (+/-200 years) then IF the dates of the MWP, as given in this article, are valid then carbon dioxide levels due the MWP should start to rise in 1950+/- 200 years and continue to rise until 2250 +/- 200 years.
https://www.webmd.com/first-aid/normal-body-temperature
Now … tell me how we have “measured” Earth’s temperature over the last … how many years?
There are only 3 aspects of global average temperature constructs that should cause concerns –
PROBITY
PROVENANCE
PRESENTATION / prosecution
Apart from these frivolous issues, it’s all good.
/sarc
Wait, I thought they had gotten rid of the MWP. They didn’t?
Historical facts sure are pesky little things!
“cyclical SST (Sea Surface Temperature) energy influences from the Atlantic could have significantly influenced cloud cover”. I don’t think that’s how it works. The major cycles in the Atlantic are over much shorter periods than the MWP/LIA cycle being discussed. The answer surely is that solar activity on the longer time scale affects cloud cover which affects SST which gives us the MWP/LIA cycle. So it’s not the Atlantic influencing cloud cover, it’s cloud cover influencing the Atlantic – but with the Atlantic still doing its own shorter cycles.
“Forests were cleared…”
But not all of them- those that were not- around that time were being well managed according to my old forestry text books.
CO2’s warming potential can be demonstrated by reviewing the original, historic, written, regional temperature records.
All these records, from all around the world, show a temperature profile that was just as warm as it is today.
So even though CO2 has been increasing since the end of the Little Ice Age around 1850, the temperatures today are no warmer than they were in the past.
Therefore, CO2 has had no visible effect on the Earth’s temperatures. It is equally warm with more CO2 and with less CO2.
Here are 600 historic written temperature charts from around the world that show what I mean:
https://notrickszone.com/600-non-warming-graphs-1/
The written, historic temperature record is the ONLY data the Hockey Stick Chart creators had to work with.
The written temperature record has a benign temperature profile where it was just as warm in the recent past as it is today, demonstrating that CO2 is nothing to worry about.
Whereas, the bogus, bastardized Hockey Stick global temperature chart shows a scary, “hotter and hotter and hotter” temperature profile for decade after decade and shows that we are living in the hottest times in human history. The rise in temperatures of the Hockey Stick chart mirrors the rise in CO2 concentrations, giving the impression that added CO2 increases temperatures. A Deliberate Distortion of the facts.
So the question of the day, of every day, and one the Climate Alarmists can’t answer is: How do you get a scary Hockey Stick chart temperature profile from regional data that has a benign temperature profile that debunks CO2 warming of any consequence? The two temperature profiles are not compatible. The written record represents reality. The bogus Hockey Stick chart distorts reality. On purpose.
You won’t see any Climate Alarmists taking up this challenge. There will be silence. That should tell you something.
Highly recommend:The Long Summer: How Climate Changed Civilization. Fascinating look at major climate shifts and impacts over thousands of years. https://www.amazon.com/Long-Summer-Climate-Changed-Civilization/dp/0465022820/
There has been a good amount of proxy data that points to earlier warm periods but it’s
not easy to find these online for some reason. Here’s one example ====>
https://billingsgazette.com/lifestyles/recreation/archaeologists-uncovering-ancient-peoples-widespread-use-of-mountains/article_b589afe6-194b-58d7-a1b1-7442b8c10220.html
From the above piece.
“The scientists are also finding that the high country wasn’t the same as we now see it. Old whitebark pine stumps have been dated to 1,100 to 2,100 years ago in places that are now 500 feet above where trees are growing now, Guenther said.
“These were happy, well-fed whitebark pine,” he said.
That points to the possibility that the high country was warmer for a period of time, maybe encouraging occupation when lower elevations were stricken with drought.”
The archology crew recorded over 175,000 prehistoric relics after explored aprox 1%
of the area.
This was world wide and over several eras IMO.
Before swallowing Gosselin’s partisan brew, you shoud read he 2017 Danish Journal of Archaeology paper
— Iron and Viking Age grapes from Denmark–vine seeds found at the royal complexes by Lake Tissø
reporting isotopic and Carbon 14 data analyses showing that wine and raisin grapes grew in Scandinavia over a thousand years before the Vikings reached Normandy, let alone the New World?
Peter Steen Henriksen and Sandie Holst of the National Museum of Denmark and Karin Frei of Museum Vestsjællandand report that in Denmark, (due East of Fife, thousands of ancient grape pips, some radiocarbon dated to the late Iron Age , and others to the age of Viking discovery, have come to scientific light in archaeological digs on the main Danish island of Zealand.
The grape pips show a 87Sr / 86Sr ratio of 0.71091 (±0.00004; 2σ), within Denmark’s strontium isotopic baseline range, indicating the seeds could be of local origin.
How does this argue against Gosselin’s
?
Now where can I find those Norwegian raisins?
There are many proxies for climate conditions.
Temperature and CO2, and precipitation levels are key elements in the definition of what we loosely term a ‘climate optimum’. Alter ONE unfavorably, and the climate is no longer optimum.
China had censuses from before 400AD. Human fertility and the Chinese population then can serve as a sensitive climate proxy, fluctuating between 45 million and 60 million for 1000 years, then more than doubled between 1014 AD and 1103AD to 120 million in the Song Dynasty, followed by a 50% drop to 60 million by 1291 AD in the Yuan Dynasty, and did not again exceed 120 million until technical gains in China brought the ability to feed millions more by the mid-18th Century AD – in the Qing Dynasty.
It is coincidental, of course, that the peak Chinese population for over 2000 years was coincident with the so-called ‘climate optimum’ in Europe and elsewhere in the world.
The continued rise of the Chinese population to 1.4 billion is due to the availability of energy, all else being favorable. That is about to change, however, as energy shortages are perpetrated globally by the morons in control who long for a return to a feudal system.
It is unfathomable to that a warming period of 300 years did not have global reach.