New Comprehensive Map By Scientists Confirms Medieval Warm Period Was Real And Global, Climate Models Faulty

Vahrenholt die kalte sonneOne of the biggest obstacles global warming alarmists have had to deal with is the inconvenient existence of the Medieval Warm Period (MWP), as there are reams of literature showing that this period was as warm or even warmer than today.

Photo right: Fritz Vahrenholt (Die kalte Sonne)

Yet, a number of global warming activists and alarmist scientists have tried air-brushing away its existence, or claimed it was a only a local North Atlantic phenomenon (just as Wikipedia does).

Now, thanks to the diligence of two German scientists, refuting or denying the existence MWP has just gotten a heck of a lot tougher. In fact from their results it is becoming clearer than ever that the MWP was real and worldwide.

 Lüning’s and Vahrenholt’s interactive Medieval Warm Period Map. The period was real and global. Click on the image and the markers to link to the literature underpinning the MWP. On the left side of the map you’ll find the entire list of the literature. The red markers show warm conditions during the MWP, the yellow markers show drought conditions, green markers show wetter conditions and the blue markers show cooling during the MWP. So far there has not been any study indicating a temperature fall!

Geologist Dr. Sebastian Lüning and chemist Professor Fritz Vahrenholt have been working meticulously on producing an interactive Medieval Warming Period Map (above) which allows easy access to the robust scientific literature underpinning the MWP.

Medieval Warm Period was a global phenomenon

Now the first results of their Medieval Warming Period Map are in, they tell us so far in no uncertain terms that not only was the MWP real in the North Atlantic, but it was in fact a global phenomenon.

So far the Medieval Warming Period Map has 157 markers plotted on it. Each plotted marker has an embedded link to the literature which shows the MWP’s existence for that location. As we can see, the 157 studies represented by the markers are scattered all over the globe.

Climate models fail to reproduce the MWP

What drove Vahrenholt and Lüning to produce the Medieval Warming Period Map?

They write here that in addition to the dubious efforts aimed at erasing the warm period from history, the climate models have so far been unable to reproduce it. Even the IPCC in its AR5 climate report (IPCC, 2013a, chapter 5.3.5) openly acknowledges the models fail reproduce the MWP warming.

Unanswered questions, faulty models

This brings up some crucial questions that Vahrenholt and Lüning pose:

How could it have been as warm as it is today when the CO2 concentration was much lower? Which climate factors were at play back then that are today not adequately accounted for in the climate models? If the models were recalibrated, what results would they show for the future?”

These are tremendously inconvenient questions for the climate modelers and scientists, and so it is not a surprise that some have tried to erase the MWP from history. And these Orwellian white-washing efforts continue today.

Lüning DkSLüning writes, in a response to my e-mail inquiry: “There are still scientists who deny the global character of the MWP. […] The most recent example where such data is needed is a publication by Young et al.”

Photo right: Dr. Sebastian Lüning (Die kalte Sonne)

The project continues…100s more studies to be plotted

Clearly Lüning’s and Vahrenholt’s MWP Map is a valuable, if not an essential tool for referencing the history of our climate. Professor Vahrenholt wrote in an e-mail:

The Medieval Warming Period Map is a resource that gives us rapid and easy access to the crucial scientific literature underpinning the existence of a worldwide Medieval Warming.”

Though the MWP Map already delivers robust results, Lüning writes that there are still hundreds of papers that need to be assessed, plotted and linked. To fund the project Vahrenholt and Lüning have been busy trying to raise the 25,000 euros needed to cover the expenses – a real bargain compared to the tens of millions flowing into the IPCC reports.

So far they have raised some 11,000 euros and the two scientists are confident they will be able to scrape together the remaining funding from private sources that is needed to finish the job.

Readers are welcome to make donations. Every amount helps:
Prof. Dr. Fritz Vahrenholt
Bank: Hamburger Sparkasse
Account No. 1280579069
Routing No.: 20050550
IBAN: DE93200505501280579069
When transferring please note: MWP-Projekt


41 responses to “New Comprehensive Map By Scientists Confirms Medieval Warm Period Was Real And Global, Climate Models Faulty”

  1. sod

    Simple question: when was that MWP?

    It doesn t make sense, when we add markers which show a MWPs at different times. So you name me the century (or half of it) that counts, and we start by dismissing the rest.

    1. Walter H. Schneider

      You poor sod, you did not take the time to read the any of referenced literature linked in the map, right?

      1. sod

        “you did not take the time to read the any of referenced literature linked in the map, right?”

        Just look at the timespans they give.

        This “MWP” attempt is the same as all others. It uses the fact, that the medieval time is badly defined. Then we add all reports of warm weather between years 500 and 1500 and completely ignore that the warm phase in source A is the cold phase already in source B.

        So i asked a simple question: which 50 year period was globally warmer than the last 30 years?

        1. handjive

          “So i asked a simple question: which 50 year period was globally warmer than the last 30 years?”

          Instead of asking “simple questions”, sod could research the answer to a simple question and incorporate the answer in his comment.

          Bonus points & notoriety for debunking Lüning’s and Vahrenholt’s interactive Medieval Warm Period Map await sod.

          Or maybe sod is in denial of the facts.

        2. handjive

          NOAA: What’s the hottest Earth’s ever been?

          The planet has sometimes been much warmer than it is now.

          One of the warmest times was during the geologic period known as the Neoproterozoic, between 600 and 800 million years ago.

          Another “warm age” is a period geologists call the Paleocene-Eocene Thermal Maximum, which occurred about 56 million years ago.

          Geologists and paleontologists think that during much of the Paleocene and early Eocene, the poles were free of ice caps, and palm trees and crocodiles lived above the Arctic Circle.

          Modern human civilization, with its permanent agriculture and settlements, has developed over just the past 10,000 years or so.

          The period has generally been one of low temperatures and relative global (if not regional) climate stability.

        3. Sebastian Luening

          @ sod
          The core of the MWP was 1000-1200 AD. Click on the respective data points or wait for our comprehensive synthesis. I think it is now time to stop denying and look at hard data. Thanks.

          1. AndyG55

            Thank you, Sebastian and Fritz for doing this valuable work.

            It is very important to bring to light the reams of information and data confirming the MWP and LIA across the globe.

            The AGW agenda cannot be allowed to bury the past.

            That past shows that current temperatures are only marginally above those of the coldest period of the last 10,000 year, and well below the temperature of most of that 10,000 year period.

          2. sod

            “The core of the MWP was 1000-1200 AD. Click on the respective data points”

            That is what i did of course. I end up getting random information over random periods of times. Some even have “colder phases” in the 1000 to 12000 period, those that have warm phases outside that period are irrelevant and should not be on the map. The same is true for extremely long periods.

            That is the reason for my simple question: Which 50 years were warmer than “today” (possibly even meaning the last 20 or 30 years?)

            PS: It would be a good idea to add the information of the end date of the data series (which will be the “today” comparison given).

        4. yonason


          I think it’s a safe bet that sod and other critics have never been so demanding of Michael Mann’s and others’ hackneyed hockey sticks (or any other of the agenda driven drivel they all purvey.

          Bad science produces bad data

          Yet they only attack conscientious attempts to get at the truth. Well, they are at least consistent, if nothing else.

    2. David Johnson

      Do you always have to be so obtuse? People may start to think you are a stupid sod

      1. Jeremy Poynton

        We already knew that…he or she is in search of a life, methinks.

  2. mcraig

    “Scythian warriors, like the one seen on display above, have been buried within the Siberian permafrost for more than 2,000 years. ”

    I asked an AGW cultist to explain this and he actually said that those mummies were buried in the ice at that time. That they actually dug into the ice however many feet deep and then filled in the hole with ice. Thus, it was not as warm 2000 years ago as today and having such a grave become uncovered with some melting means nothing.

    Or something like that. Complete and utter denial. Just like the MWP. It was covered in scientific literature by hundreds of studies and then one day a Mann-made hockey stick wiped those studies away.

    And they want us to trust them and their science no matter how hard it is to get them to show the details to us.

    1. AndyG55
  3. Dizzy Ringo

    before we all subscribe, wouldn’t it be an idea to contac t the group who have been collating lots of papers on the MWP world wide – wasn’t it the Idsos?

    1. Sebastian Luening

      @ Dizzy Ringo
      We are already in collaborative contact with the Idsos whose collection provided an excellent seed point for the mapping project. This is not about replicating their work but take it to the next level.

      1. yonason

        One cannot help but observe that if they were as critical of the “data” propagated by warmists, we probably wouldn’t be having this discussion.

        “C3 Headlines” blog posts a lot of peer review material on various warming topics. With regard to ME warming, I just performed the following search and got 489 hits
        Medieval Warm Period

        Those who can’t wait for your material to be completed are free to busy themselves with that in the mean time.

      2. AndyG55

        @ Sebastian…

        Ken gives several links to papers over on “notalotofpeopleknowthat”

        You probably already have them, but just in case. 🙂

  4. Ed Caryl

    Here is one collection:

  5. Derek Colman

    The map displays perfectly using Firefox. However when I tried to open the link in Chrome, it displayed with all the coloured markers missing. Is Google censoring this? Furthermore I could not get Internet Explorer or Edge to open the web page at all.

  6. Frederick Colbourne

    When I visited Angkor in Cambodia, I noticed that many of the dates given for the development of the culture and the royal sites were around the same dates as for the high middle ages in Europe.

    However, the climate of Cambodia may not have been reported in peer-reviewed papers, unless archaeologists have done some work on climate. Vast labour resources were used to construct the Ankor buildings, monuments and infrastructure, which is usually taken to indicate agricultural surpluses made possible by a warm and wet climate.

    1. edmh

      And that advanced civilisation failed in the Little Ice Age because the cooling climate got substantially drier.

  7. AndyG55

    And certainly the Earth was warmer through the first 3/4 or so of the current Holocene interglacial

    We are STILL very much at the COOLER end of the last 10,000 years..

  8. Lasse

    Christmas greetings from Sweden!
    And a newspaper notice to add to the evidence of an extreme MWP:

  9. edmh

    A message to distress SOD

    According to Greenland and other Ice Core data our Holocene Interglacial is now in decline.

    The current, warm Holocene interglacial has been the enabler of mankind’s civilisation for the last 10,000+ years. It’s congenial climate spans from mankind’s earliest farming to the scientific and technological advances of the last 100 years.

    • the last millennium 1000AD – 2000AD encompassing the Medieval warm Period has been the coldest millennium of the Holocene interglacial.
    • each of the notable high points in the Holocene temperature record, (the early Holocene Climate Optimum – Minoan – Roman – Medieval – Modern), have been progressively colder than the previous high point.
    • for its first 7-8000 years the early Holocene, including its high point “Climate Optimum”, had virtually flat temperatures, an average drop of only ~0.007 °C per millennium.
    • but the more recent Holocene, since a “tipping point” at ~1000BC, has seen a temperature diminution at more than 20 times that earlier rate at about 0.14 °C per millennium.
    • the Holocene interglacial is already 10 – 11,000 years old and judging from the length of previous interglacials the Holocene epoch should be drawing to its close: in this century, the next century or this millennium.
    • the beneficial warming at the end of the 20th century to the Modern high point has been responsible the “Great Man-made Global Warming Scare”.
    • eventually this late 20th century temperature blip will come to be seen as just noise in the system in the longer term progress of comparatively rapid cooling over the last 3000+ years.

    When considering the scale of temperature changes that alarmists anticipate because of Man-made Global Warming and their view of the disastrous effects of additional Man-made Carbon Dioxide emissions, it is useful to look at climate change from a longer term, century by century and also from a millennial perspective.

    The much vaunted and much feared “fatal” tipping point of +2°C would only bring Global temperatures close to the level of the very congenial climate of “the Roman warm period”.

    Were possible to reach the “horrendous” level of +4°C postulated by Warmists, that extreme level of warming would still only bring temperatures to about the level of the previous Eemian maximum, a warm and abundant epoch, when hippopotami thrived in the Rhine delta.

    Global warming protagonists should accept that our interglacial has been in long-term decline for the last 3000 years and that any action taken by man-kind will make no difference whatsoever. And its implausible that any action by Man-kind could reverse the inexorable in the short period of the coming century.

    Were the actions by Man-kind able to avert warming they would eventually reinforce the catastrophic cooling that is bound to return relatively soon.


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    […] Paper Reviewed Vilanova, I., Schittek, K., Geilenkirchen, M., Schabitz, F. and Schulz, W. 2015. Last millennial environmental reconstruction based on a multi-proxy record from Laguna Nassau, Western Pampas, Argentina. Neues Jahrbuch für Geologie und Palãontologie 277: 209-224. — See also: New Comprehensive Map By Scientists Confirms Medieval Warm Period Was Real And Global, Climate Model… […]

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  13. sdf

    I enjoy what you guys tend to be up too. This type of
    clever work and exposure! Keep up the very good works guys
    I’ve included you guys to my personal blogroll.

  14. Anthony Power

    Hello . The gentleman over at co2science have had a similar project on the go for a number of years now . Perhaps you might check out their website and combine your research

    1. sod

      “The gentleman over at co2science have had a similar project”

      Yes, they have been using a similar trick for some time now.

      Just do the following:

      click on the link from above:

      and then follow the top case study links (africa, “cold air cave”) and look at the graph you get:

      The peak is BEFORE 1000 and during the “main MWP” you will actually find a dip below zero.

      This was the first example i checked today. It is bad “science”, at best!

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  17. J.Seifert

    Hallo Sod, to your discovery of the “cold air cave”: This study is
    based on stalagtites limestone layers results and the problem with limestone layers
    and delta-O-18 out of solid stones is its high error level.
    You can detect it easily, by laying this limestone temperature graph on top of other MWP-graphs: The S.-A.-limestone graph curve is between 50 and 100 years
    to old in age. We conclude that there is no reason that the climate
    in South Africa may be 100 years AHEAD compared to the rest of the world.
    Therefore, only a SYSTEMIC PRE-DATING ERROR persists in this limestone analysis,
    however, it serves to show that a MPW took place globally, also in S.A.

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