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Australian Met Office Accused Of Man-Made Climate Change

February 16, 2019

By Paul Homewood



Graham Lloyd has picked up on the story that the Australian BOM have rewritten Australia’s temperature records for the second time in six years, and once again the rate of warming has conveniently increased.

One of the most aspects is that the BOM quietly introduced these changes last October , without announcing them:



Rather than the nation’s temperature having increased by 1C over the past century, the ­bureau’s updated homogenised data set, known as ACORN-SAT, now shows mean temperatures have risen by 1.23C.

Bureau data shows the rate of mean warming since 1960 has risen to 0.2C a decade, putting the more ambitious IPCC target of limiting future warming to 1.5C close to being broken.

Homogenisation of temperature records is considered necessary to account for changes in instrumentation, changes in site locations and changes in the time at which temperatures were taken. But the bureau’s treatment of historical data has been controversial. In recent years there have been claims that the organisation was treating temperature records in such a way that left it exposed to accusations that ideological pursuits had trumped good scientific practice.

Former prime minister Tony Abbott unsuccessfully pushed for a forensic investigation into the bureau’s methods.

A number of reviews of the ­bureau’s network equipment and its temperature data handling have been carried out. A technical panel found the homogenisation methods used were largely sound.

But a key recommendation, to include confidence levels or error margins in the data, remains ­unfulfilled. A BoM spokesman said work was under way on a number of scientific papers looking at uncertainty and confidence intervals for temperature data ­observations, adjustments and national averages.

“This work will be made available to the public following ­thorough peer review,” the spokesman said.

The bureau had fiercely defended the accuracy of its original ACORN-SAT data. But more ­recent analysis, including the ­removal of rounding errors, has effectively increased the rate of warming by 23 per cent, compared with the earlier homogenised ACORN version-one data.

Detailed technical information on the ACORN-SAT ­update was published late last year, but there has been no public ­announcement of the revised data, which is now considered the official national average temperature record. A bureau review of the ­homogenised data said the new version had “increased ­robustness and greater spatial ­coherence”.

The updating of the ACORN-SAT data coincided with the ­release last October of a new version of US weather agency NOAA’s global land temperature data set.

A bureau spokesman said ACORN-SAT version two was the bureau’s “improved official homogeneous temperature data set”. The new data set benefited from “the numerous scientific and technological advances which have occurred over the past six years, as well as the ­insights and recommendations from an independent ACORN-SAT technical advisory forum”.

“It also contains new data which was not previously available when the bureau developed the first data set,” he said.

The bureau said the updates had been independently peer-­reviewed, and the findings were that the methodology was “rigorous and reliable”.

Scientist Jennifer Marohasy said that while version two of the data had used the same set of 112 stations as had been used in version one, the data had been remodelled relative to the raw data and also relative to the remodelled version one.

The bureau said the data in version two was subjected to two rounds of homogenisation, as had been the case with version one. “In total, 22 of the 966 ­adjustments applied in version two of the ACORN-SAT data set arose from this second-round procedure,” the bureau said.

A technical analysis of ACORN-SAT 2 by the bureau said 1910-2016 trends in Australian temperature were about 0.02C a decade higher than those found in version one. It said rounding errors in version one accounted for much of the new trend.

Dr Marohasy said the bureau had not explained how it could have generated a 23 per cent increase in the rate of warming, just through updating the official ACORN-SAT ­record.

The maximum-temperature trend from 1910 to 2016 at the 112 ACORN-SAT weather stations is now an increase of 0.116C a decade. It was 0.09C a decade in the earlier homogenised data.

The minimum-temperature trend is now an increase of 0.13C a decade, compared with 0.109C in ACORN-SAT 1.

The bureau said improved ­accounting for the widespread relocation of sites out of towns during the 1990s and 2000s, and the incorporation of recent data from new sites, were also substantial contributors.

Dr Marohasy said movement of sites was meant to be part of the adjustments made in the first version of the data.

“The incorporation of data from new sites may account for some of the 23 per cent increase,” Dr Marohasy said, “because the bureau have opened new sites in hotter western NSW, while closing higher-altitude weather stations, including Charlotte Pass in the Snowy Mountains.”

  1. Athelstan. permalink
    February 16, 2019 10:38 am

    BOM, and very much like ‘our’ own wet office are primarily, political advocates stuffed full of ‘on message’ apparatchiks and certainly not organizations exclusively given to making only science based observation, it you understand that, then you see it ‘alarmism and climate prognostication’ far more clearly.

  2. Athelstan. permalink
    February 16, 2019 10:39 am

    That’s another one just gone into the ether.

    are you ‘vetting’ my posts Paul??

  3. Athelstan. permalink
    February 16, 2019 10:40 am

    And another one.

  4. Athelstan. permalink
    February 16, 2019 10:41 am

    maybe not.


  5. February 16, 2019 11:19 am

    The climate change corruption is increasing as the data continues to make the scam harder to maintain.

    • Mike Jackson permalink
      February 16, 2019 12:43 pm

      I feel you and I are thinking alike in this one, Phillip. As the scientivists get closer to that dreaded plucked-from-the-air, super-scary 2° and it becomes ever more difficult to squeeze out that last drop, they are desperate to reach that figure before the real-world climate does an about-face and it becomes impossible to keep up the pretence.

      What hasn’t yet occurred to them is that the day they can claim we have reached that figure — and bugger all happens! — their credibility is shot. At the very least we can argue that since it’s now too late to do anything to avert Armageddon we might as well all enjoy the warm weather while it lasts!

      • Athelstan. permalink
        February 16, 2019 2:40 pm

        mmm, temperate and temperance in all things MJ, how soothing you are and right – imo!

  6. Malcolm Bell permalink
    February 16, 2019 11:26 am

    It is well said that necessity is the mother of invention!

    • Rowland P permalink
      February 16, 2019 11:39 am

      Actually…. “Necessity is the plea for every infringement of human freedom. It is the argument of tyrants; it is the creed of slaves”. William Pitt, 1783.

  7. Harry Passfield permalink
    February 16, 2019 12:26 pm

    It begs raises the question, had the homgenisation indicated a cooling trend would the records have been updated, or would they still use the warmer, un-homogenised data?

    • The Man at the Back permalink
      February 16, 2019 12:40 pm

      Rhetorical Harry?.

    • Duker permalink
      February 17, 2019 4:34 am

      they are too clever to just fudge the data so they do this instead
      ‘The incorporation of data from new sites may account for some of the 23 per cent increase,” Dr Marohasy said, “because the bureau have opened new sites in hotter western NSW, while closing higher-altitude weather stations, including Charlotte Pass in the Snowy Mountains.”

      closing colder stations …who would have guessed

  8. February 16, 2019 1:52 pm

    Talking about trends as single numbers, as if the data were linear, is playing the game on alarmist terms. The world did warm a lot from around 1970 to 2000, but what happened before 1910 and after 2000? The data (homogenised by my simple methodology) suggests a distinct cyclic variability, such as maximum temperatures in the Walgett region of NSW. Sorry, but clinging to raw data is not a credible option:

  9. February 16, 2019 3:52 pm

    Reblogged this on Climate Collections.

  10. saparonia permalink
    February 16, 2019 4:53 pm

    All men are equal but some are more equal than others.

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