Current warming rather like the Medieval Warm Period. Beware of truncated data sets!

Remember the warm period in the Middle Ages just before the Little Ice Age?  Michael Mann and associates tried to erase it from the record. The hockey stick illusion was headline news for the IPCC in 2001 and now it is discreetly parked in the archives and Mann has become an embarrassment to his colleagues.

A thought-provoking piece on deep ocean temperatures has turned up and the following is some of the explanatory commentary provided on Watts Up With That.

This exposes the ubiquitous trick of the Climate Debate, in which Global Temperatures are [almost] always shown only from the depths of the Little Ice Age (clearly marked on the first graph by Gebbie), resulting in images similar to Gebbie’s Figure 2 — despite the fact that most 2 millennia reconstructions clearly show the Roman and Medieval Warm Periods as generally in the same range as the Modern Warm Period.   Given the acknowledged range of error  in any temperature reconstruction and in modern estimates of global surface temperatures (today, in absolute temperatrures,  around +/- 0.5ºC  or a range of 1ºC)  — there may be little, if any,  significant-to-the-global-environment difference  between the two periods.

The Medieval Warm period did not result in a “Climate Catastrophe”  and the [iffy] little additional 0.2°C  seen today  is very unlikely to spark a modern Climate Catastrophe either.

Author’s Comment:

A great deal of the polarization in the Climate Debate  is based on this little trick of data presentation — using a starting date  known to represent a low point  in some data set of a measurement which the author wishes to show has increased to a present high.  Failure to show the full context of the data is a type of data falsification.

 

This entry was posted in Global warming and climate change policy, Rafe. Bookmark the permalink.

37 Responses to Current warming rather like the Medieval Warm Period. Beware of truncated data sets!

  1. stackja

    ‘Climate change’ false?
    I am shocked!

  2. Nob

    What really matters is that Scott Morrison hasn’t declared climate change emergency therefore causing bushfires.

    I learned this from my dear severely educated nieces.

    This is a simplification (less verbiage) , but not exaggeration, of what they said.

  3. Roger

    Data falsification…a scientific term for lying.

  4. George

    Reading University in the UK has come up with a new global temperature chang visualisation showing the WMO temperature dataset from 1850 to the present

    In typical climate alarmist fashion, they have neglected the previous two Millenia of global temperatures which present a different picture

  5. JC

    Remember the warm period in the Middle Ages just before the Little Ice Age? Michael Mann and associates tried to erase it from the record.

    Has Mann ever responded to this and what has he said.

  6. Whalehunt fun

    You call it “data falsification”.
    I call it a criminal offence and I want the law changed so the criminals are punished with jail time and a life ban on being funded by any taxes or any government organisation. Tattooing the word LIAR on their forehead and removing their ears would complete the punishment.

  7. Whalehunt fun

    Mann’s response is to stand on the dignity of his Nobel Prize. I kid you not. The one he tried suing when a nasty Canadian denialist said he was not given s Nobel Prize.

  8. Beachcomber

    Nob at 11:47 am

    What really matters is that Scott Morrison hasn’t declared climate change emergency therefore causing bushfires.

    I learned this from my dear severely educated nieces.

    That’s the nub of it Nob. The CO2-Climate Crisis cult is easily debunked with facts, but that doesn’t matter to the fascist left establishment. They have successfully indoctrinated a whole generation and they will use this to establish global-communist government.

  9. I_am_not_a_robot

    Part of the problem is that a global surface temperature records (although unreliable) start at the point in time when the planet was recovering from the Little Ice Age, similarly the global satellite lower atmosphere series start when many thought the planet was heading for an ice age.

    For instance for some reason the extent of Arctic sea ice in Sep – Oct causes great concern (presumably as a proxy for temperature even though temperature measurements are also available), and apparently the alarmists are not aware that the Arctic was at least as warm during the 1930s.

  10. min

    A friend with a masters degree in oceanography has been explaining this to our Current Affairs group at local u3a and to friends for years. It goes straight through their ears or over their heads . We are in a blue ribbon seat area that is going woke and left so it is just not a problem with the young believing rubbish. I cannot wait to see them huddling in blankets to keep warm as we have bee promised by Chairman Dan that we will have blackouts thus summer.

  11. John A

    Err, you mean that they are falsifying a .5 degree K increase? Shocked, I am, shocked!

    0.5 K is almost indistinguishable on a graph, and even 2K would be hard to see.

  12. Elizabeth (Lizzie) Beare

    Grapes were grown in northern Britain during the Roman warm period, and I have found references in an obscure local history to Hemp being grown around Glasson Dock in Lancashire for ships’ sails. I find it interesting that this was also in an area where many Sarmartian soldiers settled after having been sent to Britain by Marcus Aurelius in the 2nd century. These people were known for using Marihuana for ritual purposes. Some of their legends are shown by folklorist Linda Malcor to bear similarities to the Arthurian legends; most think now this was as an expression of a deeper Indo-European set of mythologies, demonstrated by Grahame Anderson, who won the Pulitzer Prize for pointing this out with regard to the Arkadian kings of Mesopotamia.

    Just saying. The Orkneys were once much warmer too, going through climatic cycles as places do.
    Recent extensive archaeological work on the Orkneys suggests Skara Brae was most likely only part of a great ritual centre of a major early religion, one that rivals the scope and extent of the Salisbury plain ritual landscape where Stonehenge sits, rather than the snug domestic houses built against Orkney’s current cold that shivering people like to think of that site as representing. Trees grew on Orkney in the warmer periods.

  13. Elizabeth (Lizzie) Beare

    We are in a blue ribbon seat area that is going woke and left so it is just not a problem with the young believing rubbish.

    Min, similarly in our Blue Ribbon seat as well. A lot of older people religiously get the Sydney Morning Herald delivered and listen to nothing but the ABC. They are completely taken in by the Climate Cult.

    I’ve said here many times that the best thing Morrison could do to ensure his re-election is to mail out a pamphlet (as Gillard did with her infamous ‘black balloons of carbon’) to all Australian electors and to all schools calming the heat in this debate, telling the truth about the ridiculous claims being made and the lack of empirical evidence that there is for them.

  14. Tel

    I cannot wait to see them huddling in blankets to keep warm as we have bee promised by Chairman Dan that we will have blackouts thus summer.

    Probably won’t be quite cold enough in Victoria to require a pile of blankets in the middle of Summer.

    That said … they have outlawed the backyard summer BBQ and they cut your indoor electricity which leaves everyone eating a cold-cut sandwich and drinking a warmish tin of beer. Survivable … but I hope they all feel suitably ashamed when the rellies come over.

  15. min

    The Vikings were sailing across to Iceland and Greenland in 900s It must have been warmer then to be able to farm, raise cattle in these countries.
    As a 9 year old, 74 yers ago, we were taught about early explorers Such as Vasco da Gama, Magellan and Erik the Red and others . With the story about Greenland I was a bit perplexed as I only knew about Eskimos and igloos. In later years I studied Italian history ,the next piece of the puzzle appeared . Federico Secondo HRE wrote a book on Falconry early 1200s that is still used today and was corresponding with the Greenlanders who paid taxes to the Pope.
    They were sent an Archbishop 1054 and completed their cathedral in 1100 s from memory . No igloos for them but climate became colder. The colonies lasted 500 to 600 years according to a Danish/ inuit Greenlander, brother-in-law of neighbour.
    SBS showing a repeat of the archeologists searching for signs of Vikings in America supposedly discovered by Leif Errikson ,son of Erik the Red in 1000.

  16. Mark M

    Were people just as stupid in the MWP?

    4 arrested in Cherry Creek following [global warming] protest

    Protesters locked themselves to a sleigh they had placed on First Avenue.
    Crews from the Denver Fire Department cut them free.

    The protesters were then briefly loaded into ambulances to be examined by paramedics following their prolonged time in the cold.

    https://kdvr.com/2019/11/29/4-arrested-in-cherry-creek-following-climate-change-protest/?utm_source=dlvr.it&utm_medium=twitter

    The stupid. It burns.

  17. JC

    The Vikings were sailing across to Iceland and Greenland in 900s It must have been warmer then to be able to farm, raise cattle in these countries.

    These are not good arguments to put against Gerbil warming. Vikings could very well have been crossing the seas then, but these arguments against gerbiling are not evidence.

    Gerbiling is a very specific, albeit unproven theory. It’s that human intervention has caused temps to rise ~1 deg in the past 100 years or so. Vikings rolling over the oceans in the 900s could have been due to natural variation. People need to be persuaded gerbiling is bullshit.

  18. Nob

    I’m not that interested in warming or climate.
    It is what it is and will be what it will be.
    Whether humans caused it or not.

    It’s a giant red herring rabbit hole.

    What matters is the appalling policies being enacted and more being demanded by activists even while they insist we’ve passed yet another tipping point.

    Even in the activist dominated West, nobody really gives a shit. They don’t want the policies, nobody voluntarism pays for offsets, they vote against them when they actually get the chance and all the misanthropy and doom doesn’t inspire anybody except the idle young and idle retired of privileged classes.

    Who will diminish with the diminishing prosperity of the West, not to mention their own pathetic birthrates.

    It doesn’t matter what you think about climate, that argument is neither winnable nor losable , these policies are ruinous for no net value.

  19. People need to be persuaded gerbiling is bullshit.

    No. People need to read a few posts beforehand.

  20. Elizabeth (Lizzie) Beare

    People need to be persuaded gerbiling is bullshit.

    My argument exactly, JC. Do an investigation, Scott, and let the people know the results, untampered by those with a finger in this pie.

    The evidence for the CO2 hypothesis has not come in at all. The models have not turned out to be predictive and alternative explanations for any warming, or lack of it, are available; including natural climatic variation.

  21. Beachcomber

    Investigations and evidence and reasoned argument make make no difference to the the climate crisis hegemony. The establishment’s Big Climate dirigiste narrative is utterly impervious to contrary facts. It continues the indoctrinating through academia and the ABC-TASS media. It will continue destroying freedom and prosperity unless Western governments stop funding it. And that ain’t gonna happen.

  22. Rossini

    Nob
    #3249314, posted on December 1, 2019 at 4:55 pm

    Agree 100%

  23. egg_

    Their Greta is being parodied on 2DAY FM. The public tide is turning against the CAGW behemoth.

  24. mem

    AGW does not exist. No one has proven that it does. Therefore I shall go about business as normal rather than worrying my head off about a non existent threat. What makes me very angry though is the amount of public money that is being wasted on addressing a non-existent problem whilst greasing the palms of the merchant bankers, green energy scammers and all their sycophantic followers.

  25. If Gergis et al had followed the peer reviewed method they said they had used; they would have found a medieval warm period warmer than now. The graph showing this was truncated in the revised paper.

    If you want to see what their original results should have been; you have to put in a freedom of information request to Melbourne Uni and go and look at the graph while someone watches you to make sure you don’t take a copy of it.

    Now that’s a robust finding

    https://tthomas061.wordpress.com/2014/03/31/gergis-findings-re-surface-the-hockey-stick-lives/

    https://climateaudit.org/2012/10/28/gergis-et-al-correspondence/

  26. Dr Fred Lenin

    Elizabeth, my maternal grandmother was born inOrkney from an old Orcadian family , the family historian tells me we are probably descendants of the Skara Brae people as our name has no Norwegian or Pictish roots. The youtube items on Orkney archaeology are fascinating ,Seems Skara Brae is built on an even older midden probably 8,000 years old ,as it is Skara Brae is 3,200 BC . Its amazing to think you could be the inheritor of all this recorded and proven history, they were amazingly sophisticated for the time they lived there , fine builders With a complex religion in a hostile environment ,its astounding archaeology .

  27. Iggie

    Elizabeth
    You may be referring to the Ring of Brodgar as the religious site in the Orkneys. But yes, it was at least two degrees warmer back then.
    My maternal grandparents were from the Orkneys and as you say Fred, they called themselves Orcadian, not Scottish.

  28. CAGW has nothing to do with science. It is politics and nothing but.

  29. Dr Fred Lenin

    Iggie Orkney only became Scottish in the 1400s it was part of Norway for about 700 years before that it was part of the Pictish loose confederation of tribes .
    Archaeologists love it there best in Europe ,there’s a saying ,push a spade into the ground and you find Archaeology. A suggestion to Aussie archaeologists go to Orkney if you want the real thing ,you could spend a lifetime looking for Pommy Pascoes Dark Emu aboriginal “towns” and find bugger all ,what a misomner “an Australian archaeologist,filling museums with suspect stones and calling them “tools” ,study Orkney stone tools they are works of art ,and the could boil water 5200 years ago .
    You tube has great videos on Orkney well worth a look .

  30. DaveR

    A great deal of the polarization in the Climate Debate is based on this little trick of data presentation — using a starting date known to represent a low point in some data set of a measurement which the author wishes to show has increased to a present high. Failure to show the full context of the data is a type of data falsification.

    The second trick is to alter the temperature data from the early 1900s to today, by cooling the past, to make it look like the warming trend is continuing strongly. It isnt.

  31. iggie

    DaveR
    Here’s an example of ‘the second trick to alter temperature’.
    This is version 2 of GISS NASA global temps up until around 2010 for Darwin.

    https://data.giss.nasa.gov/cgi-bin/gistemp/show_station.cgi?id=501941200004&dt=1&ds=1

    Then they got started with their adjustments when the temps started to plateau around 2007.

    https://data.giss.nasa.gov/cgi-bin/gistemp/stdata_show_v4.cgi?id=ASN00014015&ds=14&dt=1

    You can just see the v2 graph in yellow.

    Maybe all this was done in response to Tom Wigley’s email to Phil Jones’ when he wrote:-
    ‘It would be good to remove at least part of the 1940s blip, but we are still left with “why the blip”.’

    They had to get rid of the temp increase from 1910-1940s – easy done.

    And the BoM is as guilty as GISS NASA.

  32. Kneel

    “The second trick is to alter the temperature data from the early 1900s to today, by cooling the past, to make it look like the warming trend is continuing strongly.”

    Oz BoM – compare ACORN-1 to ACORN-2. Not only is the past cooler, the present is warmer. This is the SAME raw data, just processed differently. And it has “error bars” smaller than the difference between the two “adjusted” data sets!

    The killer for me is the total lack of ability to even consider they might be wrong.
    Steve McIntyre essentially said “looks like you forgot to carry the one” and got pasted as a denier. We should trust them because they are climate scientists talking about climate. But we should also trust climate scientists over professional statisticians when it comes to stats. Ahh, yeah, sure – why not?

    And they keep recycling the same crap – PAGES2K was retracted because of too many mistakes. Not picked up by the peer review, but instead by an unpaid “denier”. Their latest effort is the very same crap, slightly modified, then published with not enough time for the same kind of scrutiny prior to IPCC report time. So like the Mann hockey stick, this will be a poster child – until it’s proven wrong, and will then, like the hockey stick, be dumped down the memory hole.

    For some odd reason, they seem to think they can adjust the publication record the same as they adjust the temperature record, and no-one will notice. To them, the WayBack Machine web archives don’t exist – or maybe they are run by evil deniers or something.

    Mann says he didn’t lose his court case against Tim Ball and won’t pay the costs awarded against him. Contempt of court, much? Certainly not! The court is obviously in the pay of Big Oil. After all, Mann didn’t lose – he just got distracted by trying to save the world and hence didn’t have the time to provide discovery to a bunch of evil, fossil fuel funded deniers. For several years.

    Yeah – Big Fossil, which they say paid 100’s of millions for “denier” science. Never mind the BILLIONS spend on “believer” science.

    Or Phil Jones’ infamous “I have 25 years invested in this. Why should I give you the data when all you want to do is find mistakes?”

    Unprecedented stuff happening – just don’t pull back the curtain, or you might notice that “Arctic Sea Ice” only goes back to 1979, a known cold period. You should look at GLOBAL temps not what’s happening locally – but of course, when it comes to ice, we don’t look at global just NH because otherwise you might find out the global ice is growing.
    Look at Katrina et al – mad hurricanes, right? Yeah, after the longest USA landfalling hurricane drought on record. All the people killed by it! (ignore the 95% reduction in weather related deaths during the last 100 years). Never mind that 2018 was the first year on record with no large tornados in the USA!

    It just goes on and on (and on, and…)

  33. iggie

    Kneel
    ‘Not only is the past cooler, the present is warmer.’
    Here’s an example of what you’re saying. Here is part of the climate summary for 2011.
    ‘The Australian area-averaged mean temperature in 2011 was 0.14 °C below the 1961 to 1990 average of 21.81 °C. This was the first time since 2001 (also a wet, La Niña year) that Australia’s mean annual temperature was below the 1961–90 average.’

    Now check BoM’s recently adjusted Time series graph which not only gets rid of 2011’s below average mean but also 2001.

    http://www.bom.gov.au/climate/change/#tabs=Tracker&tracker=timeseries

    A result no doubt due to the adjustments in ACORN2 . Now they can say there has been no below annual average means this century.

    BTW, every annual mean since 1995 has been adjusted up, except 2018.

    The 2011 climate summary.
    http://www.bom.gov.au/climate/current/annual/aus/2011/

  34. cohenite

    Gerbiling is a very specific, albeit unproven theory. It’s that human intervention has caused temps to rise ~1 deg in the past 100 years or so. Vikings rolling over the oceans in the 900s could have been due to natural variation. People need to be persuaded gerbiling is bullshit.

    The MWP being as warm as today is evidence. CO2 was lower yet it was as warm then as today. Combine that with the fact that the modern warming, since about 1850, occurred mostly at the beginning of that period when CO2 levels were similar to the MWP. Ergo no relationship between temperature and CO2.

  35. JC

    The MWP being as warm as today is evidence.

    Sure, but dishonest arseholes, like for instance, Tim Lambert, once argued that this was possibly European event and not on a world scale. How is that countered. Is there evidence that it wasn’t?

    CO2 was lower yet it was as warm then as today.

    How do we know this though? Co2 could also be variable.

  36. iggie

    JC
    ‘Sure, but dishonest arseholes, like for instance, Tim Lambert, once argued that this was possibly European event and not on a world scale. How is that countered. Is there evidence that it wasn’t?’

    Here are all the studies. Seems fairly global from these.
    https://www.google.com/maps/d/u/0/viewer?mid=1akI_yGSUlO_qEvrmrIYv9kHknq4&ll=-3.81666561775622e-14%2C38.03818700000005&z=1

  37. Kneel

    [re MWP being non-global] “How is that countered. Is there evidence that it wasn’t?”

    https://www.google.com/maps/d/viewer?mid=1akI_yGSUlO_qEvrmrIYv9kHknq4&ll=-3.81666561775622e-14%2C38.03818700000005&z=1

    Click the map pins to get details of the published research for that location.
    The peer reviewed research appears to support this was a global event, although perhaps not globally synchronous.

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