New Study Confirms Medieval Warm Period Was Indeed Global, And As Warm As Today

Here’s another blow to the global warming alarmist scientists, who have been claiming that the Medieval Warm Period was a local, North Atlantic phenomenon, and did not really exist globally. What follows is a report on yet another paper contradicting this now worn out claim.
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China: Warm phase of the 20th century was not unusual in context of the last 2000 years

By Dr. Sebastian Lüning and Prof. Fritz Vahrenholt
(German text translated by P. Gosselin)

New research papers on China’s climate past are appearing almost weekly. From them it is becoming obvious that the climate of the last centuries and millennia was governed by natural fluctuations.

On 8 August 2017 the Chinese Academy of Science published a remarkable press release. The most important news was already given by the sub-heading: The warm climate of the the past decades was nothing unusual in the context of the last 2000 years in China. Already in the pre-industrial years scientists were able to make out similarly warm periods:

Warm Periods in the 20th Century Not Unprecedented during the Last 2000 Years

A great deal of evidence relating to ancient climate variation is preserved in proxy data such as tree rings, lake sediments, ice cores, stalagmites, corals and historical documents, and these sources carry great significance in evaluating the 20th century warming in the context of the last two millennia.

Prof. GE Quansheng and his group from the Institute of Geographic Sciences and Natural Resources Research of the Chinese Academy of Sciences, collected a large number of proxies and reconstructed a 2000-year temperature series in China with a 10-year resolution, enabling them to quantitatively reveal the characteristics of temperature change in China over a common era.

‘We found four warm epochs, which were AD 1 to AD 200, AD 550 to AD 760, AD 950 to AD 1300, and the 20th century. Cold periods occurred between AD 210 and AD 350, AD 420 and AD 530, AD 780 and AD 940, and AD 1320 and AD 1900. The temperature amplitude between the warmest and coldest decades was 1.3°C,’ said Prof. GE.

The team found that the most rapid warming in China occurred over AD 1870–2000, at a rate of 0.56 ± 0.42°C (100 yr)−1; however, temperatures recorded in the 20th century may not be unprecedented in the last 2000 years, as reconstruction showed records for the period from 981 to 1100, and again from 1201 to 1270, were comparable to those of the present warm period, but with an uncertainty of ±0.28°C to ±0.42°C at the 95% confidence interval. Since 1000 CE—the period covering the Medieval Climate Anomaly, Little Ice Age, and the present warm period—temperature variations over China have typically been in phase with those of the Northern Hemisphere as a whole.

They also detected some interactions between temperature variation and precipitation change. The ensemble means of dryness/wetness spatial patterns in eastern China across all centennial warm periods illustrate a tripole pattern: dry south of 25°N; wet from 25°–30°N; and dry to the north of 30°N. For all cold periods, the ensemble mean drought/flood spatial patterns showed an east to west distribution, with flooding east of 115°E and drought dominant west of 115°E, with the exception of flooding between approximately110°E and 105°E.

The general characteristics of the impacts of climatic change historically were negative in the cold periods and positive in the warm periods. For example, 25 of the 31 most prosperous periods in imperial China during the past 2000 years occurred during periods of warmth or warming. A cooling trend at the centennial scale and social economic decline run hand-in-hand. The rapid development supported by better resources and a better environment in warm periods could lead to an increase in social vulnerability when the climate turns once more to being relatively colder.

‘Throughout China’s history,’ Prof. GE added, ‘both rulers and the ruled have adopted strategies and policies to cope with climate change, as permitted by the prevailing geography and circumstances of the time.'”

Figure: 2000-year temperature reconstruction in China (Image by GE Quansheng)

26 responses to “New Study Confirms Medieval Warm Period Was Indeed Global, And As Warm As Today”

  1. sunsettommy

    Heck of a lot more here:

    Medieval Warm Period Project

    http://www.co2science.org/data/mwp/mwpp.php

    papers for South America,Antarctica,Asia, Australia and New Zealand too.

    Warmists fight them because it destroys their narrative.

    1. tom0mason

      Indeed sunsettommy,
      It seems the usual meme got canned once the first few papers were released. Unfortunately all the usual suspects are still chanting the usual claptrap about it not being global — like they’ll ever know.

      Funny thing is most people do not appreciate that quite warm events occurred during the cold periods, and very cold events happened in the warm periods but that’s how natural variation goes.

  2. Cloud

    Yet another study ignoring the rapid rise after 1998. Even without the last 19 years, the authors acknowledge the 20th century warming was the most rapid. And with reported errors of up to +-.42°C, the past 2 warm periods mentioned (.56 and ~.4) are essentially overwhelmed by uncertainty.And the idea that China temps prove the phenonena was global is silly.

    1. Kenneth Richard

      Cloud,
      http://notrickszone.com/global-warming-disputed-300-graphs/
      Here are over 300 temperature graphs from all over the globe, including over 100 published this year alone (2017), that not only show that the 20th/21st century temperatures aren’t unusual or unprecedented, but in many cases today’s temperatures are still colder than most of the last 10,000 years.

      Yet another study ignoring the rapid rise after 1998.

      http://www.woodfortrees.org/plot/rss/from:1998/to:2017.6/plot/rss/from:1998/to:2017.6/trend/plot/uah6/from:1998/to:2017.6/plot/uah6/from:1998/to:2017.6/trend

      Can you explain why you believe the 0.1 C temperature rise trend since 1998 (just 0.05 C per decade) is “rapid”?

      At the beginning of the Holocene era, Northern Hemisphere temperatures rose by 4 or 5 degrees C within a span of a few decades, and sea levels rose at rates of 5 meters per century. Compare this to 0.05 C per decade chanage since 1850 (and 1998-present), or the 0.17 of a meter of sea level rise per century since 1900.

    2. sunsettommy

      Cloud, that was a very poor post you made. It is easy to see that you are another warmist, ignoring the IPPC Per decade predictive failures. They from 1990 onward, say it should warm around .30C per decade.

      I see that Kenneth post the RSS,UAH satellite data to show that it is LESS than .05C per decade rate,since 1998.

      Snicker…….. not even close!

      1. SebastianH

        Can you cite where in the IPCC report it says that it should warm 0.3 °C per decade?

        And why would a possible predictive failure change the fact that global average temperatures increased rapidly in the last 50 years?

        1. Kenneth Richard

          http://www.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_spm.pdf
          “Based on current model results, we predict:
          Under the IPCC Business-as-Usual (Scenario A) emissions of greenhouse gases, a rate of increase of global mean temperature during the next century of about 0.3C per decade (with an uncertainty range of 0.2°C – 0.5°C)

          1. SebastianH

            A more current one maybe? Yonason at least linked to AR4 which says the prediction range of the 1990 report was between 0.15°C and 0.30°C warming per decade and the observed warming between 1990 and 2005 being 0.2°C per decade.

        2. sunsettommy

          Sebastian, I cited this to YOU about 8 times!

          It is clear you ignored it.

          No it didn’t increase rapidly either,another lying narrative since you can’t show it using HadCrut4:

          http://www.woodfortrees.org/graph/hadcrut4gl/from:1960/mean:12/plot/hadcrut4gl/from:1960/trend

          It is around .16C per decade trend.

          Here is Dr. Jones own data based chart showing that ALL THREE per decade warming trends since the 1880’s are around .16C rate.

          http://jonova.s3.amazonaws.com/graphs/hadley/Hadley-global-temps-1850-2010-web.jpg

      2. yonason

        @ chatbot_SebH

        “Temperatures to rise 0.3-4.8 C this century, UN panel says”
        https://phys.org/news/2013-09-temperatures-century-panel.html

        Took me less than a minute.

        “And why would a possible predictive failure change the fact that global average temperatures increased rapidly in the last 50 years?” – Chatbot_SebH

        Temps have not risen any more rapidly than they have naturally in the past, especially since the pause persists at 20 years, so that’s a red herring.

        Their inability to predict anything meaningful means they are unreliable, especially when they keep doing it after having been caught out.

        1. yonason

          P.S., with a range of 0.2-4.8 they allow themselves a LOT of “wiggle room,” as in, “we pridict temps will go up 0.48 deg C per decade, …unless they dont.

          USELESS GARBAGE!!!

          1. yonason

            Link for that is this…
            https://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm-projections-of.html

            “For the next two decades, a warming of about 0.2°C per decade is projected for a range of SRES emission scenarios. Even if the concentrations of all greenhouse gases and aerosols had been kept constant at year 2000 levels, a further warming of about 0.1°C per decade would be expected. {10.3, 10.7}”

          2. tom0mason

            And yonason, these pointless temperatures amalgamations only indicates that something is changing not how, when, where, or what.
            They may indeed indicate climate changes but I thought we already knew that, they do not, can not, give any indication of how, when, where, or what will change. And that is a big hole in the UN-IPCC argument.

          3. yonason

            @tom0mason 31. August 2017 at 12:22

            “Somethings going on here, but you don’t know what it is, do you, …Mr. (Phil) Jones?!” – Bob Dylan

          4. SebastianH

            they do not, can not, give any indication of how, when, where, or what will change. And that is a big hole in the UN-IPCC argument.

            Ehm, the IPCC reports are full of how, when, where explanations. You can’t just distill those collected findings to just one number, the global average temperature change in a height of 2m.

            But it is one good indicator that the energy budgets are changing. Others would be ocean heat content, downwelling and upwelling radiation measurements, etc.

        2. SebastianH

          “Temperatures to rise 0.3-4.8 C this century, UN panel says”

          I see and from a prediction made by evaluating different scenarios made in 2013 you conclude that the predictions haven’t been met in reality in the last 4 (!) years?

          Temps have not risen any more rapidly than they have naturally in the past, especially since the pause persists at 20 years, so that’s a red herring.

          http://www.woodfortrees.org/plot/hadcrut4gl/plot/hadcrut4gl/to:1960/trend/plot/hadcrut4gl/from:1960/trend

          Their inability to predict anything meaningful
          http://imgur.com/a/VMA13

          1. sunsettommy

            Bwahahahahahahahahahahahahahahahahahaha!!!!!

            Your use of that HadCrut data actually destroys your entire argument,since the warming rate per decade from 1960 is around the .16C rate.

            From 1990 based on HadCrut4,

            the trend is about .20C which is still well below the IPCC per decade predicted rate. This is built around several significant El-Nino’s,the latest one drindling away,this the cooling down will continue. Eventually the warming rate will drop back down.

            The IPCC from 1990 on wards said it should be around .30C per decade.

            Thank you for the comedy hour.

          2. Kenneth Richard

            Your use of that HadCrut data actually destroys your entire argument,since the warming rate per decade from 1960 is around the .16C rate.

            Actually, the IPCC (HadCRUT) has it at 0.12 C per decade since 1951, with a slowdown to 0.05 C per decade since the beginning of the 21st century.

            https://phys.org/news/2013-09-key-ipcc-climate.html
            “Warming since 1951 has been about 0.12 C per decade. This slowed over the past 15 years to 0.05 C per decade, but the timescale is too short to read anything into that yet, says the [2013 IPCC] report.”

            Hedemann et al., 2017
            http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3274.html
            https://dl.dropboxusercontent.com/u/75831381/Hedemann%202017.pdf
            “[T]he origin of the recent hiatus may never be identified. … The observed trend deviated by as much as −0.17 ◦C per decade from the CMIP5 (Coupled Model Intercomparison Project Phase 5) ensemble-mean projection—a gap two to four times the observed trend. The hiatus therefore continues to challenge climate science.”

            Climate models also predicted that Southern Hemispheric sea ice would decline in recent decades. Instead, it’s grown, in line with the Southern Ocean cooling trend since 1979.

            Comiso et al., 2017
            http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-16-0408.1
            The Antarctic sea ice extent has been slowly increasing contrary to expected trends due to global warming and results from coupled climate models. After a record high extent in 2012 the extent was even higher in 2014 when the magnitude exceeded 20 × 106 km2 for the first time during the satellite era. … [T]he trend in sea ice cover is strongly influenced by the trend in surface temperature [cooling].”

          3. yonason

            If SebH wants to be terrified by this…
            http://c3headlines.typepad.com/.a/6a010536b58035970c01b7c8bb7a00970b-pi
            …who am I to forbid it.

          4. SebastianH

            From 1990 based on HadCrut4, the trend is about .20C which is still well below the IPCC per decade predicted rate.

            You should definitely read yonason’s AR4 link above … they aren’t predicting 0.30°C per century. That’s just the upper bound of a range.

          5. sunsettommy

            Kenneth,

            I was starting from 1960, because that is the start year Sebastian, chose.

            It is funny that he didn’t think it through well here.

          6. SebastianH

            It is funny that he didn’t think it through well here.

            About that, you keep mentioning the 1990 IPCC prediction (range 0.15°C – 0.30°C) and now the change per decade from 1960 was wrongly predicted by them?

            From the AR4 report:
            “Since IPCC’s first report in 1990, assessed projections have suggested global average temperature increases between about 0.15°C and 0.3°C per decade for 1990 to 2005. This can now be compared with observed values of about 0.2°C per decade, strengthening confidence in near-term projections.”

            1960 is a good starting year when you want to show that the claim “Temps have not risen any more rapidly than they have naturally in the past” is nonsense. Around that time global temperature decoupled from the influence of solar radiation: http://iopscience.iop.org/article/10.1088/1748-9326/7/3/034020/pdf

          7. sunsettommy

            Sebastian,

            1990-2017 as per the HadCrut4 set,

            http://www.woodfortrees.org/graph/hadcrut4nh/from:1990/mean:12/plot/hadcrut4gl/from:1990/trend

            The trend is clearly LESS than .20C per decade.

            Here is what they said in the 1990 report you ignored several times already,since the then BUSINESS AS USUAL scenario was an underestimation of future CO2 emission growth scenario over time.

            “Based on current model results, we predict: under the IPCC Business-as-Usual (Scenario A) emissions of greenhouse gases, a rate of increase of global mean temperature during the next century of about 0 3°C per decade (with an uncertainty range of 0 2°C to 0 5°C per decade)…”

            The 1990 business as usual for yearly CO2 emission rate was then about 1.5 ppm,now it is over 2.15 ppm per year.

            This means their per decade rate is actually on the low side. Which indicate that .40C per decade is now the better estimate based on their formula.

            You seem to forget that their emission scenario was based on the 1.5 ppm rate,which they posted their median .30C per decade rate on. But the CO2 rate went up much faster than the IPCC anticipated,here is a chart showing the increase since the 1950’s

            Atmospheric CO2 Growth Rates
            Decadal Average Annual Growth Rates
            Mauna Loa Observatory (MLO)
            1958 – 2014

            https://www.co2.earth/co2-acceleration

            Meanwhile the more accurate and relevant temperature data set shows a lot less warming than any of the ground based data sets,

            http://www.woodfortrees.org/graph/uah6/from:1990/mean:12/plot/uah6/from:1990/trend

            Like I stated, you didn’t think it through.

        3. tom0mason

          yonason,

          And for the more mathematical people here, there is always this,
          https://www.omicsonline.org/open-access/New-Insights-on-the-Physical-Nature-of-the-Atmospheric-Greenhouse-Effect-Deduced-from-an-Empirical-Planetary-Temperature-Model.pdf by Ned Nikolov and Karl Zeller.
          They stick to the correct paradigm with three closely related concepts: temperature, energy, and heat being treated correctly, and not as all AGW advocate screw-up by equating properties of heat as being those of energy and vise versa.

          1. yonason

            @tom0mason 31. August 2017 at 5:32 PM

            Oh, thanks! I almost missed this.

            I’ve long been frustrated by the lack of treatment like this. Not surprising the the warmunistas wouldn’t, but I really thought that at least some skeptics would have written more than zero about it.

  3. CFB_C

    I took a look at the warming chart sunsettommy posted a link to and I don’t understand why people measure the rate of change of temperature from a low to a high?? Can anyone explain to me why the temperature change isn’t measured from peak to peak or trough to trough? Wouldn’t that be more representative of the actual underlying changes in temperature? I think they end up being something around 0.04C to 0.06C/decade.

    Anyone have a good reference for this??

    Thanks!