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HadCRUT5 Adjusts Temperatures Upwards Again

December 16, 2020

By Paul Homewood



Man made global warming!!




The Morice paper claims the extra warming has come from an improved representation of Arctic warming and a better understanding of evolving biases in sea‐surface temperature measurements from ships.

In fact it is not scientific to average together Arctic temperatures with the rest of the planet, as it is comparing apples with oranges. It all has to do with latent heat and water vapour, as Tony Heller brilliantly explained:



Climate scientists know all of this, so why do they continue to promote unscientific gibberish?


And it is of course the Arctic region where most of the warming has appeared:





As for fiddling around with sea‐surface temperature measurements from ships, you can use these to come up with any results you want.

The whole concept of a global temperature is, in any event, meaningless. What matters are temperature trends at a local level.

And when we examine these, for instance the CET, we find nothing to alarm us whatsoever.

  1. December 16, 2020 10:51 am

    Temperature is an intensive variable and thus cannot be averaged anyway. An average temperature is a meaningless concept. The Met Office is full of scientific fraudsters who must realise this. But they do not care as long as they get loads of money and recognition.

    • Ian Magness permalink
      December 16, 2020 11:03 am

      Can you define “intensive variable” and the relevance to climate science for those less knowledgeable than you please.
      Thanking you in advance…

      • December 16, 2020 12:16 pm

        In plain language, an intensive quality belongs to an object and cannot be averaged with that of other objects. Thus attempts to estimate global temperature changes rely on “anomalies” deviations from a baseline observation. Which raises another distortion, since temperatures vary naturally in the high north much more than in the tropics.

        Clive Best provides this animation of recent monthly temperature anomalies which demonstrates how most variability in anomalies occur over northern continents.

      • December 16, 2020 12:22 pm

        Ron, how do you manage to insert a graphic like that into a reply?

      • December 16, 2020 12:53 pm

        Sorry that link was wrong. Should have been

      • December 16, 2020 1:01 pm

        pardon, I had used that link in a post at my own blog. Such links don’t always display; may be a WordPress feature.

      • December 16, 2020 2:03 pm

        Ian: Although I would not normally recommend Wikipedia a good definition is given at

        An intensive variable is one that does not change as you increase the size of something (such variables as temperature, density) whereas an extensive variable is one which increases as the size increases (such as mass, volume).

        You might say “what is the average air temperature in my house?” Well obviously it’s the average temperature of all the rooms (volume weighted). But wait, what is the temperature of each room. The temperature of the air in a room will vary from location to location within the room. For example near a radiator it might be 30C, but near a window it could be 15C, it could be 18C near the floor and 20C near the ceiling. So to get the temperature (average) of a room, it would either have to be in thermodynamic equilibrium (ie the same everywhere) or you would have to measure the temperature of every air molecule in the room, an impossible task. So the average air temperature in your house is a meaningless concept, just as the global average temperature is.

      • December 16, 2020 3:19 pm

        Basic definitions…

        Here’s a link that explains the basic difference, without adding thermodynamic considerations.

        Another basic video, (again, no thermodynamics considered).


        I mention thermodynamics because it isn’t just the fact that something is intensive or extensive that’s the problem here. While that’s an important consideration, the thermodynamic properties of materials and processes also affect the final temperature, often bigly.

        Warmists oversimplify everything without regard to accuracy. Or, as it often seems, relying on our not realizing how misleading they are.

        Ron is much more on top of this than I am, though, so for depth and perspective, see his article.

      • Ian Magness permalink
        December 16, 2020 3:33 pm

        Ron, Phillip and Yonason,
        Thank you all very much – I have learned something today.

      • December 16, 2020 4:03 pm

        My last was to Ian Magness on the definitions he asked about, but I’m starting to read Ron’s article, and while it’s excellent, I don’t see those terms defined anywhere, or even used.

      • December 16, 2020 5:46 pm

        @Phillip Brattby

        I like your house analogy. As I remember from my winters in New England…

        Sit near even a closed window, on a very cold day get a chill
        Sit near on an un-carpeted portion of the floor, too cold.
        …near the hot air vent, too hot.
        …get too close to a steam radiator, OUCH!

        Thanks for the memories.

      • December 16, 2020 9:30 pm

        Hi Ron, I was just intrigued how to insert jpg’s/animated gifs into a comment because I have not found how to do it.

    • December 16, 2020 3:14 pm

      Averaging is pretty useless when it comes to temperature. I have been in the Arctic in winter when the sun does not shine and the temperature was -56C, In the summer when the sun shines 24hrs the temperature can be +25C. The swing of 81C gives an average of -15C but this is a useless measure.

      • December 16, 2020 4:52 pm

        Indeed JBS. Some years ago Roger Pielke Sr. did excellent research on a set of weather stations in Colorado to investigate a strange phenomenon. The regional average from the 11 stations did not reflect any of the individual records that went into the calculation.

        The study linked below showed that numerous differences in the landscapes at each site meant that temperature and precipitation measurements differed significantly from one to the other, even when located a few kms apart. Not only absolute differences, such as altitude would create, but also the trends of changes differed due to terrain features. Thus the averages are not descriptive of any of the local realities. In my studies of temperature trends, I took Pielke findings to heart and focused on the pattern of change observed in each specific site.

        The paper is available here:

    • dave permalink
      December 16, 2020 6:06 pm

      “Intensive quantities” are often averages; and you CANNOT average averages.

      A good example of intensive quantities is the ‘average weight’ of the boys in a school-class and the ‘average weight’ of the girls in the same class. Now, consider the ‘average weight’ of the whole class. Can you calculate this average merely by knowing the first two averages? The answer is ‘no.’

      Twenty boys of average weight 100 pounds with ten girls of average weight 80 pounds is thirty children of average weight 93.33 pounds.

      Ten boys of average weight 100 pounds with twenty girls of average weight 80 pounds is thirty children of average weight 86.66.

      The average of the two averages is 90.0 pounds.The class will never have this average except if by chance the number of boys is identical with the number of girls.

      ‘Temperature’ was found, in the 19th C, to BE a sort of average.
      Thus ended the idea (for any informed scientist since 1850) of averaging temperatures!

  2. December 16, 2020 10:55 am

    Given the relative stability of satellite data, maybe not as big a deal as it used to be?

    • December 16, 2020 12:09 pm

      But it’s inaccuracy is.

      • December 16, 2020 12:39 pm

        Good point. Thanks.

      • December 16, 2020 6:13 pm

        Speaking of “inaccuracy,” listen to Carl Mears justify tampering with his satellite data to conform to the already tampered surface data, with the lower satellite accuracy as his excuse. Begins at 2:08. I’ll use an html code for it, since just posting the link doesn’t preserve the start-time information.

        See here.

        Giving him the benefit of the doubt, maybe he made the video to explain why he caved to their pressure, to get them off his back, and to alert other scientists who know that the justification for what he’s saying is nonsense? …like a prisoner of war, in the propaganda film his captors made, blinking morse code with his eyes about the real situation?

  3. Chaswarnertoo permalink
    December 16, 2020 11:13 am

    They can’t even keep their lies straight.

  4. Phoenix44 permalink
    December 16, 2020 12:05 pm

    When you adjust data because you have found a new way of understanding it, how likely is it that every single time you find a new way, it moves i the same direction?

    I would assume that it is highly unlikely.

    I can see no reason why every single time the data needs to be adjusted in the way that suits their argument. It’s simply not plausible.

    • Broadlands permalink
      December 16, 2020 1:04 pm

      NOAA has been very good at adjusting monthly temperatures for older years going back from 1940 to 1921 for all 48 states. They have taken the official US Weather Bureau monthly data and, with few exceptions (California) lowered all of them. Many have seasonal adjustments. This is the opposite of what one would expect if removing UHI effects was important.

      • December 16, 2020 6:25 pm

        “This is the opposite of what one would expect if removing UHI effects was important.”

        That seems obvious, doesn’t it. They tell us that they have to correct for the UHI effect, but for some reason that “correction” invariably results in higher, not lower, modern temperatures.

        I’ve been keeping an eye out, and you’re the first person I’ve seen to articulate that issue. (I’m sure others have, but I haven”t come across them)

      • Phoenix44 permalink
        December 17, 2020 9:34 am

        And that is another example of completely unlikely adjustments. If errors are random rather than systematic then over a large data set the errors will average out. On Monday I read it too high, on Tuesday too low. But for the errors to be almost exclusively in one direction requires systematic error – but they don’t show that. They claim its random whilst showing non-random error. In many areas that would be sufficient to prove fraud.

    • December 16, 2020 6:19 pm

      What I find amusing is that prior to a narrow window of time before which data is adjusted down, and after which it’s adjusted up. Conclusion – It was only during that brief historical period that climate scientists knew how to correctly read a thermometer.

  5. Gerry, England permalink
    December 16, 2020 12:06 pm

    Funny how every adjustment made to temperature records result in higher temperatures, it being worse than ‘they ‘ thought or both.

  6. donald penman permalink
    December 16, 2020 12:12 pm

    I think that global or regional temperature is transient and not anomalous a changing seasonal average would tell us if was getting warmer or colder just the same as an anomaly but an anomaly removes the transient nature of temperature. Weather patterns are random rather then transient, we still had weather patterns during the ice ages and the previous warm periods.

  7. December 16, 2020 12:19 pm

    Small point but never do I see in any graphical presentation data from the Climate Fictionfactory with clear labelling of the of mixed nature of the presented data. There is a mix of proxy, mercury thermometer and digital data in their graphs and yet NO clear separation of source and NO corresponding error bars. How do they get away with this because to do so without clearly separating sources is not how scientific data is presented. They know that and any “Pal Review” which rubberstamps any paper containing such figures know that also.

  8. MrGrimNasty permalink
    December 16, 2020 12:54 pm

    Over the last few days the Arctic has cooled more than 5C and the globe 0.5C and the SH is devoid of all global warming ( all relative to their cool period baseline – chosen because “1979-2000 represents conditions prior to rapid Arctic warming”).

    DMI Arctic ice extent is pretty much the same as the last few years, volume on the lower bounds, Antarctic is still above the 30yr median and considerably higher than last year.

    A little while back there were some record high temperatures claimed in parts of Australia, but the SH anomaly was close zero, so clearly whatever caused those temperatures was not global warming – more likely weather/UHI and inadequate historical records. Now some elevated parts of the SH seem to have had some summer snow.

    The summer heat in Verkhoyansk is a distant memory, -40/-46C is the Dec. normal.

    In England, a yearly mean CET all-time record looks unlikely at the moment, the mild spell now has fewer days around 12C, and the cooler end to the month has firmed up.

  9. Broadlands permalink
    December 16, 2020 1:21 pm

    Those who might be interested in studying the Equatorial Pacific ENSO will find that HadlSST1.1 has never been adjusted, going back to 1870. However, NOAA data only go back to 1950 and they have adjusted their 3-month ENSO values, but only for those years after 2000.

  10. Douglas Brodie permalink
    December 16, 2020 1:41 pm

    I agree with Paul that our domestic HadCET temperature series shows no cause for alarm, see

  11. CheshireRed permalink
    December 16, 2020 2:00 pm

    Sickening levels of fraud. These racketeers should be in jail.

  12. ThinkingScientist permalink
    December 16, 2020 2:12 pm

    The key point for the met office is that the changes bring Hadcrut5 much more in line with the CMIP6 forcings. That’s the point of the exercise. CMIP6 total forcings show warming must commence around 1905 – 1910. And be flat or briefly cooling prior to that.

    Doesn’t look as though they have have changed anything that would affect the two points I always present about the Hadcrut4 data:

    1. The rate of warming 1910 – 1945 and 1975 – 2010 are almost identical but the CMIP6 forcing in the latter period is 3x larger than the former. Explain that.

    2. The glacier melt data (LeClercq & Oerlemans 2012) and sea level rise data (Jevrejeva 2014) both clearly show onset of modern warming commences around 1840 – 1850. At least 50 – 60 years earlier than indicated by the global temperature data. Explain that.

    • ThinkingScientist permalink
      December 16, 2020 2:20 pm

      A postscript to my own post

      McKay & Kaufman3. 2014 Arctic temperature reconstruction shows an obvious modern temp. trend commencing around 1820. Explain that.

      • December 16, 2020 7:20 pm

        Recovery from the Mount Tambora eruption (1815), then recovery from the Little Ice Age.

      • Graeme No.3 permalink
        December 16, 2020 8:30 pm

        And Glacier Bay in southern Alaska shows retreat of the ice from sometime in the 1780’s.

        And it was noted early that the ice was sitting on the rock floor at/near the entrance (so not due to warm water getting under the ice initially).

  13. December 16, 2020 4:57 pm

    I think this is worth re-posting…

    What the warmist activists at NOAA and NASA do is to slightly modify the temperature data. While that doesn’t make a large change in the actual temperatures, it DOES make a huge change in the anomalies, which are what they always use to argue as “proof” of any warming that may or may not be occurring, but which can’t be determined because the data has been so degraded by their tampering.

  14. David V permalink
    December 16, 2020 4:58 pm

    Apparently the adjustment is based on better understanding of arctic temperatures. Since no one reached either pole before 1908 it seems to me that estimates of Arctic or Antarctic temperatures from 1850 to 1900 must be based on very little real data. It seems that having calculated a mean global value using those non-existent data they have reimagined what they might have been to come up with a new value. Am I missing something?

    • Graeme No.3 permalink
      December 16, 2020 8:34 pm

      The temperatures in the HADCRUT data from 1855 to 1858 are based on ONE thermometer in what is now Indonesia. Half the globe from one spot????

  15. December 16, 2020 7:42 pm

    Snow cover hasn’t changed for 25 years on average. I guess, if you believe HadCRUT, that means the melting point of ice has been rising steadily.

    These people are so like the industrial statisticians in the Soviet Union where production numbers were entirely mythical.

    • Phoenix44 permalink
      December 17, 2020 9:42 am

      The thing about the USSR was that it suited everyone to believe the lies. The interesting thing was that the only people who didn’t know it was all lies was the Politburo. It’s fascinating to read about Gorbachev”s realisation that his entire view of both the world and the USSR was based on false information. From Stalin onwards, the KGB reports on the US described what Soviet leaders wanted the US to be like, not what it was actually like.

      We have a similar situation now where the state information services provide the picture that our politicians want rather than what is reality. Hence texture shocks of Credit and Trump and more to come I suspect.

  16. howard dewhirst permalink
    December 17, 2020 5:21 am

    Would it be possible to get all of the different versions on one chart? They seem to be – as always, cooling pre WWII and warming post?

  17. cookers52 permalink
    December 17, 2020 8:41 am

    The CET only shows upward trend from 1980.

    So when the scientific consensus changed to global warming the records showed warming from that point.

  18. Gerry, England permalink
    December 17, 2020 12:06 pm

    Rather than adding to the long post at the top, the graphic that Ron shows and comments that most of the warming has been in the northern hemisphere should I think note that the majority of measuring stations are in the that hemisphere. Most of the land mass is in the north and there records there are likely to be longer. If you see the globe marked with the locations of temperature monitoring you can only note how little of the globe does actually have any temperature monitoring, thus rendering the global average highly suspect.

    As has been mentioned above, there can be quite marked local variations. Near me is Redhill aerodrome which being that is it connected with flying has a weatherstation. It is a grass airfield and sits in a noted frost hollow which means it is unrepresentative of the surrounding area just as much as nearby Gatwick Airport is given all the buildings surrounding it, the expanses of tarmac and jet engine heat.

  19. ThinkingScientist permalink
    December 17, 2020 3:41 pm

    Note something else about the Hadcrut5 download data set – unlike the Hadcrut4 time series the Hadcrut5 time series data are only available for download from the Hadley Centre in NetCDF format. I am starting to think the Met Office is deliberately making raw data less accessible.

    I understand why NetCDF might be preferred for grids, but not for time series. Even for grids, there are more easily accessible formats including sorted/ordered flat ASCII.

  20. Peter S permalink
    December 17, 2020 6:38 pm

    The above discussion reminds me that a man with his head in the oven and his feet in the freezer can feel, on average, just right.

    Over at WUWT there is a post that shows that we have no idea about average sea temperatures or whether they are warming or cooling.

    Then add to that that the oceans warm the atmosphere and not the other way around. Furthermore, solar (SW) radiation warms the oceans but GHG warming has no efficient way of doing that. The oceans dominate our climate.

    No Tricks Zone reports that temperature changes of 8-16 degrees can take place in less than 100 years by unexpected changes in ocean currents. Climate scientists are stuck in the mindset that external forcing is needed to make a temperature change and apart from aerosols and changes in orbit there is just CO2. No wonder climate science is rubbish.

  21. December 20, 2020 1:01 am

    HadCRUT5 is cited in the forthcoming IPCC report but the data was not available to reviewers of the second order draft of that report. I said when I reviewed the report that this situation was unsatisfactory.

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