The Guardian, Temperatures, Misinformation (Part 1)

From Jennifer Marohasy’s Blog

Jennifer Marohasy

I have just sent the following to Environment reporter,
The Guardian | Australia

Hi Graham (Readfearn)

I received an email from you late yesterday indicating you are writing a story, which I assume you are publishing in The Guardian this weekend. I am of the impression that it will suggest my research into the Bureau of Meteorology’s temperature data over the last decade amounts to ‘harassment’ and ‘misinformation’. I also understand that you will primarily cite the work of former Bureau chief Greg Ayers in defence of the Bureau’s current methods and its non-compliance with World Meteorological Organisation (WMO) recommendations, which are for the measurement of air temperatures as a numerical average rather than an instantaneous spot reading from electronic equipment.

You have asked for a response by 1 pm today. There is a lot to cover, and I only have a limited amount of time, moreover, I am fitting this response in among other commitments; therefore, I am labelling this Part 1. I will post Part 1 on my blog, with the intention of providing additional details in Part 2 when I have more time, and after the publication of your article.


I assume your immediate interest follows the provision of a limited amount of parallel data for Brisbane Airport following the Administrative Appeals Tribunal Hearing on 3 February that I attended with John Abbot. I note, however, that in the subject line of your email you write: ‘Acorn-Sat and temperature records – response.’

The parallel data are the measurements as they are recorded at the same time and place by a mercury thermometer, which can be compared to temperatures as recorded by a platinum resistance probe connected to a datalogger. There are approximately 38 of these parallel data sets that run for 10 to 20 years each. These are held by the Bureau mostly as transcribed handwritten reports. It is the Bureau’s policy to not make these handwritten reports public.

The ACORN-SAT (Australian Climate Observations Reference Network – Surface Air Temperature) records are something else entirely. These are the homogenised/remodelled temperature series that are promoted by the Bureau as showing global warming. ACORN-SAT data is publicly available and tends to show very different trends to the raw temperature data series for the same locations as archived in the Australian Data Archive for Meteorology (ADAM). ACORN-SAT is derived from ADAM following industrial scale remodelling.

• You can find the ACORN-SAT series at the Bureau’s website here:

• You can find the ADAM series at the Bureau’s website here:

The parallel data is secret. As I mentioned above and emphasise again, it is the Bureau’s policy to not make these handwritten reports public.

I make this point upfront, because there has been much confusion regarding the availability of the parallel temperature data since Graham Lloyd’s article ‘Mercury Rising in BOM probe row’ was published on the front page of The Weekend Australian last month.

To reiterate, the parallel data are the temperatures that are handwritten into the Field Books of Meteorological Observations, including both the temperatures as recorded by a mercury thermometer, and those from the platinum resistance probes, at the same place and on the same day. ADAM provides the observations from either probe or mercury, ACORN-SAT are the ADAM temperatures series remodelled/homogenised, while the parallel data are two sets of readings – from both probe and mercury on the same day at the same location.

I spent the first of several minutes of a pre-recorded interview with Michael Condon from ABC NSW Country Hour last month arguing with him about this. He was repeating incorrect information from the Bureau’s Chief Customer Officer, Peter Stone.

Specifically, Condon incorrectly claimed that the Bureau makes all its temperature data publicly available on its website, including the parallel data. This claim, that is apparently being repeated across university campuses, flatly contradicts the opening paragraphs of Lloyd’s article. Lloyd correctly explained that it was only after a Freedom of Information request, three years of arguing with the Bureau (including over the very existence of these Field Books/A8 reports and whether their release was in the public interest), and then the case eventually going to the Administrative Appeals Tribunal on 3 February 2023, that some of the parallel data for Brisbane Airport was released.


This current dispute is separate from my issue with the homogenisation process which produces the ACORN-SAT data.

The issues as reported over the last month in The Australian newspaper, on ABC radio’s Country Hour, and Sky Television, following the hearing at the Administrative Appeals Tribunal is concerned fundamentally with the raw temperature data, ADAM, which I argue has been corrupted since the introduction of platinum resistance probes.

In short, we are arguably no longer comparing apples with apples.

It is important to compare data from mercury thermometers with data collected by probes since 1996, through in-depth analysis of the parallel temperature data, which the Bureau both refuses to make publicly available or analysis in proper detail.

Claims that there must be peer-reviewed of our preliminary findings is a red herring. Proper studies require that more parallel data be made available.

Peer review is a process developed to encourage rigour in scientific debates, but is increasingly being used as a bludgeon and shield against critic.

The matters raised by John Abbot and me are technical not scientific matters. The Bureau’s refusal to accredit its process as conforming to WMO guidelines is a matter of quality control. Sunshine is the best disinfectant but the Bureau’s refusal to release the parallel data – which would allow the apples with apple comparison – is a scandal of public administration.

Freedom of Information regulation exists to facilitate the release of such data held by institutions such as the Australian Bureau of Meteorology. It is true that I have pursued this issue with the Bureau and some members of its staff for close to a decade. But if they had acknowledged the genuine issue and the public interest in sharing the data, in say, 2015, we could have moved on. If I have, at times, speculated as to the motives behind non-compliance, that is an anterior not a posterior result of the Bureau’s approach.

I mostly make mention of the maximum temperature data as recorded by a mercury thermometer. The three types of temperature series held by the Bureau: ADAM, parallel data, and ACORN-SAT also include minimum temperature series recorded by alcohol thermometers, which like mercury thermometers are liquid-in-glass as opposed to the electronic devises comprised of platinum resistance probes hooked-up to data loggers also known as automatic weather stations.


Back in 2017, after John Abbot and I published a most important analysis of the application of machine learning for evaluating anthropogenic versus natural climate change (GeoResJ, Volume 14, Pages 36–46), you published a piece in The Guardian full of ‘misinformation’ that generated a good amount of ‘harassment’ and vilification.

While your 2017 article helped prolong a storm of personal abuse on Twitter – led by Gavin Schmidt, the director of the Nasa Goddard Institute for Space Studies – in the six years since then there has never been any criticism or rebuttal published in the peer-reviewed literature of that work in which we describe mathematically the natural cycles that have contributed to warming and cooling over the last two millennia.

It is now six years since you helped spearhead that attack, which attempted to have our paper retracted, yet it remains an important and published contribution to climate science – and it is beginning to be cited.

Your attack did prompt me to write a plain English rebuttal that many non-scientists have found useful in understanding the novel technique that John Abbot and I have developed over the last 10 years for forecasting not only temperature, but also rainfall.

It remains of concern, to both John Abbot and I, that with the mainstream climate science community refusing to consider the benefits of advances in artificial intelligence for mining historical climate data for more reliable forecasting of droughts, floods and cyclones, ordinary people continue to suffer. Our series of peer-reviewed publications showing a better way are ignored because the Bureau remains wedded to the theory of catastrophic human-caused global warming and general circulation models for forecasting, despite their inability to replicate past cycles of climate change or demonstrated practical skill at forecasting even a few months ahead.

My plain-English rebuttal of your previous misreporting of our work, and some of our more technical climate science publications, can be found at

Climatelab Pty Ltd is a company that I founded, and that has conducted consulting work in climate science, including with the Indonesian Bureau of Meteorology through a collaboration with the Queensland University of Technology.

Given your tendency over the years to mischaracterise John Abbot and myself primarily as ‘IPA Staffers’ and, variously, John as a computer scientist and myself as a biologist, before I answer the two questions that you sent late yesterday, and then make some comment on the limitations of Greg Ayers’s published notes, please take the time to understand sometime of our qualifications and interests, detailed below.

In this, Part 1, I will elaborate on how the parallel data and the ACORN-SAT series, which you have made the subject line of your email, are different but related.

In Part 2, after the publication of your article, I will re-explain the public interest in the parallel temperature data that was the cause of John Abbot’s most recent FOI application and which brought about the hearing at the Administrative Appeal Tribunal on 3 February this year.

Also in Part 2, I will likely explain how we intend to publish our findings as they pertain to the Brisbane parallel data, and also the parallel data that I hold for Mildura.

It is worth noting that there is a requirement for the Bureau to make the specifications for the four different types of custom-designed probes – which are now used across Australia for recording temperatures in automated weather stations including at airports – publicly available. There are also so many other issues to address. But let me begin by explaining the link between ACORN-SAT and the parallel data, given the extent of the confusion, including in – as suggested by – the subject line of your email.


Back in 2014 I gave a talk at the Sydney Institute about the remodelling of temperature data in the creation of the ACORN-SAT series. The notes from this address are still relevant and can be accessed here:

These 2014 speech notes quote Gavin Schmidt from a Twitter conversation back in 2014 in which I explain why it is nonsense to use temperature data from radically different climatic zones to remodel and change temperatures as they were recorded by military personnel at the airbase at Amberley, near Brisbane. Gavin Schmidt replied, ‘@jennmarohasy Your question is ill-posed. No-one changed the trend directly. Instead procedures correct for a detected jump around ~1980.’

If we look at the maximum temperatures recorded at Amberley, and also the nearby locations of Brisbane Airport and the Brisbane Botanic Gardens, for the period ‘around 1980’, we see that the annual average maximum temperature rose during the period of that drought, and then dropped somewhat dramatically during the wetter years that followed (Chart 1). This is often the pattern we see in raw temperature data across Australia before it is remodelled/homogenised.

Indeed, the longest available maximum temperature series for the City of Brisbane does not show a patten of warming consistent with global warming theory (Chart 1, green series).

This temperature series, which extends from 1896 to 1986, is perhaps one of the longest continuous series for anywhere in the Southern Hemisphere, with measurements taken by government meteorologists using standard equipment (a mercury thermometer in a Stevenson screen). The pattern in this temperature series is consistent with many others from northern and eastern Australia, showing cooling to about 1960 and then warming (Chart 1). Within the 60-year trend of cooling, followed by warming, there are shorter temperature cycles that tend to correspond with periods of droughts and floods.

Chart 1. Annual mean maximum temperatures recorded in the Brisbane region based on publicly available ADAM temperature series.

It is the case that minimum temperatures at Amberley, for example, cooled after 1980; key institutions around the world have remodelled this reality, changing the cooling to warming, as shown in Chart 2 (Figure 3 in my notes from my talk to the Sydney Institute).

Chart 2. The annual mean minimum Amberley (near Brisbane) temperature series, green is based on daily values downloaded from the ADAM database, red is based on daily values downloaded from the ACORN-SAT series at the time I gave the Sydney Institute address back in 2014. The ACORN-SAT temperatures are continually revised.

If Twitter was around at the time George Orwell was writing the dystopian fiction Nineteen Eighty-Four, I wonder whether he might have borrowed some text from Schmidt’s tweets, particularly when words like ‘procedures correct’ refer to mathematical algorithms reaching out to ‘nearby’ locations, which are in fact across the Coral Sea and beyond the Great Dividing Range, to change what was a mild cooling trend at Amberley from 1941 through to 2013, into a dramatic warming one, for an otherwise perfectly politically incorrect temperature series.

The temperatures at Amberly were correctly measured in the first place, and yet the Bureau has changed them with the creation of its official database ACORN-SAT. These are temperatures that were recorded before the introduction of resistance probes with data loggers in the late 1990s.

It is my contention that since November 1996 the system the Bureau has used for temperature collection may not be fit for purpose, and indeed may need to be remodelled.

While the Bureau – quoting former director Greg Ayers – claims its new method, which is taking the last one-second reading each minute using resistance probes connected to a data loggers, provides a maximum temperature reading equivalent to a traditional mercury thermometer, at the same time the Bureau admits to needing to remodel/homogenise temperatures from locations as distant as Darwin and Cape Otway, because of the equipment changes. This is logically inconsistent. Indeed, as Graham Lloyd, reported back in 2019: ‘The bureau has defended its homogenisation processes, which it said were needed to account for non-climate influences and changes in equipment.’

You can find that story here:

The question for me continues to be whether the probes that have replaced mercury thermometers at most of the Bureau’s 700 official weather stations are recording the same temperatures that would have been recorded using a mercury thermometer. The Bureau is not consistent on this point.


John Abbot has qualifications in science including a BSc from Imperial College London, an MSc from the University of British Columbia, a Master of Biotech from The University of Queensland and a PhD from McGill University. He has published more than 100 papers in peer-reviewed journals. He has held research and faculty positions in universities in Canada and Australia in chemistry and chemical engineering departments, as well as in industry, over a combined period of more than 20 years. His research includes studies of complex kinetic phenomena relating to industrial processes.

During the past decade, he has undertaken research relating to climate phenomena with a particular interest in application of neural networks, a type of AI, resulting in more than a dozen research publications collaborating with myself. Studies include forecasting rainfall in Australia, with several published papers each receiving more than 100 citations in the scientific literature.

Dr Abbot also has qualifications in law with Juris Doctor and LLM degrees from the University of Queensland and has been admitted as a solicitor. He has published papers in legal journals including topics relating to obtaining climatic information through Freedom of Information.

I am a scientist with experience in processing data, including temperature data for long-range weather forecasting. I have worked with the Indonesia Bureau of Meteorology (BMKG) under contract with the Queensland University of Technology teaching statistical modelling techniques for long-range weather forecasting.

The accuracy of my rainfall forecasting method, developed with John Abbot and using a sophisticated statistical model based on advances in machine learning, is dependent on the integrity of the historical temperature record. Our method for rainfall forecasting is detailed in peer-reviewed publications in international climate science journals.

I also have a long-standing interest in evidence-based public policy. I am a public intellectual with a weblog, hundreds of articles published by Fairfax Media, News Ltd including in The Australian, and I have appeared on various Australian Broadcasting Corporation programs including the Q&A panel and The Science Show.


You write:

A former BoM director and CSIRO scientist, Greg Ayers, has published peer-reviewed papers testing several of your claims. Namely, on the potential effect of using automatic readings from the final second of each minute on temperature records and trends, and whether the bureau’s automatic probes effectively are an average over the previous minute (satisfying WMO guidelines). Ayers says critics should publish their findings in peer-reviewed journals, but he says he has “seen a lot of assertion but not much science” and he, together with a climate scientist, question why critics of the bureau do not publish their specific claims in reputable peer-reviewed journals. How would you respond to that?

It is our intention to publish our findings, ideally this will be after the Bureau releases the 12 years of parallel data that it continues to hold for Brisbane Airport, and key A8 reports that it has withheld from me for Mildura, particularly the parallel data for Mildura pertaining to September 2012.

Considering the analysis by Greg Ayers, which will be discussed in more detail in our published papers and reports, the following includes some preliminary thoughts, shared in goodwill.

What Ayers appears to have done is validate the temperature probes under ideal or near ideal conditions. Note that I can’t speak to the actual conditions at the sites he used, but I assume that he would generally choose sites that met good practice, Mildura excepted, which he apparently picked out because I had highlighted it.

The scatter in the samples in his papers is low: for example, Fig 16, page 179 of Ayers, shows the differences in Tmax and Tmin (1 second) for the Mildura site and the equivalent four sample averages. They are minimal, suggesting that noise is low and the system is generally well-behaved. There are very few samples beyond +/− 0.075C. This is what he would have hoped to see, and why he published the paper. It does make his point quite well.

However, my preliminary analysis of the Brisbane data tells a different story. The relevant chart is the scatter plot of the difference (Chart 3).

Chart 3. The difference between daily values after transcribing the numbers from the A8 Forms over the Easter break. This information was provided to both News Ltd and the Bureau, about a week before I published the same at my blog.

In the Brisbane data most of the daily probe samples are at least 0.1 C away from the mercury and there are a lot that are more than 0.2 C away. The question is why?

What is the expected measurement error of the mercury thermometer?

What happened in early December 2019, both with the very low readings followed by the step change in average reading, as shown in Chart 3? Was there a fault followed by a repair and recalibration? If this is the case, why is the ADAM temperature series is complete for this period, and shows no quality issues?

Overall, the Brisbane data show there is a lot more scatter than Ayer’s papers would suggest, and some of it is well over +/− 0.5 C. Why?

If the Bureau wanted headlines supporting global warming, more scatter is better: you get more hot day records that way.

The advice to me from an analogue engineer who has expertise in this type of measurement is:

As you know, I would start by investigating RF (radio frequency) interference as a source of the scatter. This can be a source of both random and systematic errors.

On a different note, I have not been able to find any information about the temperature probes referred to in the papers by Greg Ayers. Do you have any photos of one?

The temperature probes I have seen on the Rosemount website are industrial probes suitable for both liquid and air temperature measurement. In liquids they respond quickly, with a time constant of a few seconds. In air, the response time is much longer, depending on the air flow, humidity, etc. Intuitively a settling time constant of 40 – 80 seconds in air seems reasonable, although I’ve never tested one in air myself. [Ends]

I do not understand why the Bureau does not make this information public, including time constants and pictures of the probes used at Brisbane and Mildura over the years.

The Bureau has transitioned from probes of a lesser mass balance and likely longer time constant to a 4mm version that is likely to produce a greater scatter for the same weather. It uses probes from at least 4 different suppliers, and claims each are custom designed. The specifications have never been published. They are a secret.

I have been asking for this information, including through requests both to Rosemount and the Bureau, since at least 2015. It is critical to understanding the Bureau’s measurement technique particularly given there is no numerical averaging as recommended by WMO.


You write:

One climate scientist is quoted as saying the criticisms of the bureau’s temperature record amount to “harassment” and characterises them as “misinformation”. While this comment is not directed at you, you are named in the story and have been at the heart of many of the criticisms in the past. How would you respond to the assertion that the bureau has been subjected to harassment and misinformation over the course of the last decade? [Ends]

I have always acted in good faith. In the case of the Brisbane data, when it was finally provided to me, I spent my Easter break copying numbers from more than 1,000 handwritten reports and undertaking a preliminary analysis. These values, by way of an Excel spreadsheet, and my analysis were provided to the Bureau via Graham Lloyd at The Australian. A full week before I made any media comment the Bureau had an opportunity to show the errors in my analysis. Nothing of substance has been forthcoming. Rather, instead, there has been a misinformation campaign suggesting that the parallel data is already public – by confusing it with the ACORN-SAT series.

There has been no harassment on our part. All the Bureau needs to do is produce the data that John Abbot and I have reasonably requested over the years and without undue delay.

The harassment, obstruction and misinformation has been by the Bureau. As reported by John Abbot in The Australian earlier in the week:

It is important to know the temperature measurements from the different types of equipment, if reliable continuous temperature records are to be constructed for each site so that temperature changes in recent decades can be accurately compared with earlier records extending back to the start of the industrial era.

Small differences in temperature measurement between the two types of equipment, perhaps 0.2 C to 0.5 C are not negligible in the context of global warming where the public is constantly being told that a rise of 1.5 C above pre-industrial era will have dire consequences.

The original FOI request for parallel temperature data for Brisbane Airport was made in December 2019, as well as other sites at later stages.

One of the tactics used is to allege that the documents requested do not exist. The documents requested did exist as they were referred to in BOM reports that list the sites at which parallel temperatures have been collected and the time periods. The proof is that we have finally received parallel temperature for Brisbane after more than 3 years, showing claims to the contrary were nonsense.

Another of the tactics used to prevent, or severely limit, public access to government held documents is to erect cost barriers. This was indeed the case with the BOM. The agency involved is entitled to calculate an approximate processing cost in providing the documents requested under FOI.

However, FOI legislation allows an applicant to request a fee waiver, for example on grounds of hardship or public interest regarding the information sought. The BOM rejected my fee waiver request on public interest grounds. The BOM stated that the parallel temperature data sought was only of personal interest to me, and that I stood to gain financially because I could use this information in the course of my employment. It is astonishing that the BOM could take the position that accurate quantification of atmospheric temperature changes over the past century has very little or no general public interest when the public is constantly being told that there will be drastic consequences for the planet if the threshold of 1.5 C atmospheric temperature increase is exceeded.

An applicant is permitted to request a review by the Australia Information Commissioner if unsatisfied with decisions made by a government agency regarding accessing documents under FOI. In July 2020, I requested a review by the Information Commissioner on two counts – existence of the documents requested and secondly the issue of fee waiver on public interest grounds. The OAIC agreed with the BOM on the non-existence of the documents and has so far made no finding on the second count after nearly two years. [Ends]

Thank you for the opportunity to respond.

Yours sincerely,
Jennifer Marohasy BSc PhD.

A PDF of this letter is available for download Readfern-BOMTemp-Response-F.

Gideon Rozner, John Abbot and Jennifer Marohasy at the Administrative Appeal Tribunal on 3rd February 2023.
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May 5, 2023 2:51 pm

I don’t know how Jennifer finds the time to ward off the continuous pack-attacks from the C.C.C. (Climate Crisis Cult).

If she observed and published a statement one morning such as “It looks like a sunny day outside”, the C.C.C. would immediately launch a Twitter storm about how Ms Marohasy was spreading ‘misinformation’, on account of the official forecast from the BoM was that the afternoon would bring “scattered clouds”.

Jennifer Marohasy
Reply to  Mr.
May 5, 2023 9:17 pm

Thanks Mr. It does get tiring. Worst when Graham Readfearn published something on 25th August 2017 that was hugely derogatory about both John Abbot and myself. John spent the next few days trying to find a defamation lawyer. And I have kept the replies from one of the defamation lawyer who ended up being so critical of John for daring to question climate change science. I think John was the first ‘denier’ who had ever contracted him, and was outraged when he started to understand John’s position on AGW. So, they got arguing.

Meanwhile it was my birthday on 26th August, which everyone missed, because they were so angry with Readfearn, my mother included. So now when I am forewarned of something from The Guardian/Readfearn I make sure I give a comprehensive reply. Not that I didn’t back in August 2017, but it was probably too technical for Readfearn. So now I try and make it plain English and more comprehensive.

There is nothing in The Guardian today, at least. I’m sure the article was already written. Hopefully it has been binned.

Last edited 1 month ago by Jennifer Marohasy
Ben Vorlich
Reply to  Jennifer Marohasy
May 5, 2023 11:48 pm

I’m amazed you managed such a comprehensive reply at short notice in a limited time

Bill Johnston
Reply to  Jennifer Marohasy
May 6, 2023 3:59 am

Oh dear.

Dear-o-dear as my mother used to say in her get-over-it voice; spilit milk and all …

Reply to  Bill Johnston
May 6, 2023 8:19 am

So having one’s reputation trashed in a public forum is just something to be gotten over?
Do you give that advice to everyone? Or just to those you disagree with?

Rich Davis
Reply to  Jennifer Marohasy
May 6, 2023 6:38 am

Jennifer, may I ask a basic question? Why continue to ask to waive costs?

As was (quite properly) done with Dr Ridd’s legal funding, why not turn to WUWT and the broader climate realist community to raise the money at this point?

Wouldn’t it emphasize the reality that the BoM are hiding the truth if we raised the necessary funding to pay the fees, yet they come up with a new excuse?

Certainly it was good to put them on record with the absurd allegation that there is no public interest. Why don’t we now agree to pay and demonstrate that their true motivation is to hide the truth? What new absurdity will they surface to avoid releasing the data?

Perhaps the campaign could be set up with the stipulation that if ultimately new roadblocks are erected to stonewall the FOI request, the money would pay legal fees and/or support a worthy climate realist organization.

I hope you’ll consider this approach. Thank you for all you do. You’re a treasure!

Jennifer Marohasy
Reply to  Rich Davis
May 6, 2023 5:08 pm

Thanks Rich Davis, The legal advice is we could pay the money, and then be told the money has been spent searching for documents that don’t exist. the way the legislation is formulated you can pay with no guarantee anything will be delivered.

Rich Davis
Reply to  Jennifer Marohasy
May 7, 2023 10:13 am

I’m truly grateful for your response.

The legal advice was certainly sound at the time, but my suggestion is related to further demonstrating their bad faith.

At a minimum they have already admitted to the existence of some data that has not been turned over, am I wrong? Even to state that hundreds of years of scientifically relevant evidence has been willfully destroyed would in my opinion be worth paying to establish as fact.

Do you know the price? How does it compare to what was raised for Peter Ridd?

Reply to  Jennifer Marohasy
May 6, 2023 3:54 pm

Readfearn’s article is up on The Guardian now Jennifer.

At the bottom, he links to your response letter on your website.

Earlier, he intimates how you make the BoM “climate scientists” suffer from anxiety and cry.

(Readfearn himself has been known to shed tears & sobs over someone (Christopher Monckton no less) making mincemeat of him in a debate over agw.)

So take that Jennifer, you big bad bully 🙂

Pathetic, isn’t it?

Bill Johnston
Reply to  Mr.
May 6, 2023 3:54 am

Dear Mr

Here we go again with another rave.

Marohasy has never undertaken regular weather observations or filled-in an A8 form.

Otherwise she would know that comparing different instruments that due to their location within a screen, cannot measure exactly the same parcels of air, and whose day-to-day differences are autocorrelated, is an invalid application of paired t-tests.

Confusing herself is one thing, stirring faux-debate by confusing everyone else is factors worse.

instead of ranting as an expert, she should put her data and her analysis in the public domain.

Yours sincerely,

Dr Bill Johnston

Reply to  Bill Johnston
May 6, 2023 4:49 am

Maybe BMO should publish all their data (unadjusted) for us all to see?

Last edited 1 month ago by Greytide
Reply to  Greytide
May 6, 2023 8:22 am

Don’t you understand, people who aren’t great, like Dr. J, simply aren’t capable of understanding the raw data. That’s why it has to be carefully adjusted by experts prior to it’s being presented.

Bill Johnston
Reply to  MarkW
May 6, 2023 4:48 pm

Dear MarkW,

I’ve seen plenty of data, rough data, good data, all sorts of data.

With colleagues I undertook standard weather observations at a cooperative site for about decade. I’ve checked the that instruments were correctly calibrated, checked field books (A8 forms), sent monthly returns to the Bureau.

I also worked with a private company comparing automatic weather station probes with manually observed thermometers in the 1980s and with colleagues I have deployed various brands of AWS at remote field sites.

Ask me a sensible question about weather data and I will do my best to answer it.

Kind regards,


Reply to  Bill Johnston
May 6, 2023 8:21 am

How dare the peons ask to see your work.
Shouldn’t they know already that you are incapable of error and that they should just return to their meaningless lives so that you can get back to saving humanity.

Reply to  Bill Johnston
May 6, 2023 10:16 am

You can rave all you like, Bill.

Rich Davis
Reply to  Mr.
May 7, 2023 10:03 am

Isn’t raving mad his default setting?

Rud Istvan
May 5, 2023 2:56 pm

Jen taking hack flack means she is over the target. PRT’s obviously have less thermal mass than mercury max/min thermometers, so will automatically log at least some higher 1 minute temperatures. The parallel data is needed to know by how much, so they can be adjusted to be comparable to the older mercury record. Manufacturing warming by changing measurement methods without calibration (which BMO did, but hid, hence the FOIA fight) is IMO a subtle form of scientific misconduct.

Nick Stokes
Reply to  Rud Istvan
May 5, 2023 3:23 pm

PRT’s obviously have less thermal mass than mercury max/min thermometers, so will automatically log at least some higher 1 minute temperatures.”
No, it isn’t obvious. You can have as much thermal mass as you like. And they do match them.

The parallel data is needed to know by how much”
There is much parallel data actually published. No-one, including Jennifer, seems much interested in that. Blair Trewin in his report sec 4.1 listed the results of six such comparisons, with far better analysis than we ever get from Jennifer (who won’t release her data).

which BMO did, but hid, hence the FOIA fight”

There was nothing to hide. As far as we can say from what Jennifer will divulge, the Brisbane instruments differed by about 0.05°C.

Reply to  Nick Stokes
May 5, 2023 3:36 pm

Chapter 3 in that report is called
Homogenisation methods
Which indicates their main focus and involves a major work program to do so.

I didnt have time to read it in depth but their idea of ‘parallel data’ is different , comparing a town site with the later relocation to nearby airport site.
eg Port Lincoln

Yes , there is much *two stations parallel data* , but the unpublished data is the two methods , one station kind. Brisbane Airport

Nick Stokes
Reply to  Duker
May 5, 2023 5:52 pm

but their idea of ‘parallel data’ is different , comparing a town site with the later relocation to nearby airport site.”

Yes, it is. And it is the right idea. They want to know how different the readings are now from what they would have been had the change not happened. So the measure the change between the old instrument in the place where it was, and the new instrument in its place. And if there is a difference, they correct for it.

Reply to  Nick Stokes
May 5, 2023 5:58 pm

Then they can release the one station two methods data as well and show the corrections. ( roughly 30 sites?)
But no.

Nick Stokes
Reply to  Duker
May 5, 2023 10:23 pm

Again I see that there is agitation about these unposted cases, when no-one is interested in looking at the cases that have been posted.

Reply to  Nick Stokes
May 5, 2023 11:53 pm

Your link was for those towns with 2 stations in parallel not one station two methods.
Paternalistic to assume BoM know what’s good for researchers

Nick Stokes
Reply to  Duker
May 6, 2023 3:07 am

Paternalistic to assume BoM know what’s good for researchers”
So who else does? The BoM has to prioritise its efforts otherwise it will run around endlessly trying to satisfy a dozen Jennifers. The Australian people need more than that.

Reply to  Nick Stokes
May 6, 2023 8:26 am

Just be upfront about it and publish all the data in the first place.
I just love how Nick assumes that everyone should be satisfied with whatever the government scientists decide we should have.

Reply to  MarkW
May 6, 2023 4:12 pm

Stokes has decended to the bottom of the swill well. Frankly, I find his misinformation here exceedingly tiresome. He is in afforded too much respect here by some. Was a time when he expressed considered arguement, now very rarely.

Reply to  Nick Stokes
May 6, 2023 8:24 am

Fascinating, Nick actually thinks that his “trust us, we are the experts” gig is going to fly in a site filled with experts.

Reply to  Nick Stokes
May 6, 2023 6:50 am

If they find a difference and correct for it, how do they know which is the “right” one and which the “wrong” one that needs correction?
We meet this situation quite often in experimental science. It can need a further step, such as a third parallel device, or other tactics.
In this case, given the millions of prior LIG observations in Australia’s historical record, the exercise seems to be to hold the LIG to be correct ant to adjust the Pt sensor data through hardware or software.
So, where is the disclosure of the corrections to the Pt probe data, which would need to be calculated for every station now using AWS, automatic weather stations.
Even if the corrections were close to zero, it is probably a good idea to say so. That would more more like what WMO guidelines expect.
Geoff S

Nick Stokes
Reply to  sherro01
May 7, 2023 12:33 am

If they find a difference and correct for it, how do they know which is the “right” one and which the “wrong” one that needs correction?”

They don’t. And it doesn’t matter. That is the thing about anomalies. They are looking for a station that is representative of the region. Either would do. But the change in going from one to the other is not something that the region experienced. That would affect the anomalies.

We had that in Melbourne. The station shifted from city to Olympic Park, which is near the river, and cooler. So which is right? It doesn’t matter, But you have to adjust for the change.

old cocky
Reply to  Nick Stokes
May 7, 2023 1:28 am

We had that in Melbourne. The station shifted from city to Olympic Park, which is near the river, and cooler. So which is right? It doesn’t matter, But you have to adjust for the change.

Is it cooler, or milder (smaller range)?
Penrith has the weather station near the Olympic Regatta Centre, so tends to have higher minima and lower maxima than nearby locations.

Adjusting for the change is the tricky part, even with a parallel run for a couple of years. The differences between sites in La Nina years may be different to El Nino years.

Nick Stokes
Reply to  old cocky
May 7, 2023 2:35 am

The ACORN V2 site description says
The Olympic Park site has substantially cooler temperatures, both maximum and minimum, than the previous site, with the differences most prominent on cool days in the warmer months, as winds from the southwest quadrant at the previous site passed directly over the Melbourne CBD. There are only slight maximum temperature differences between the two sites on days with northerly winds, and hence only slight differences in the behaviour of extreme high temperatures.”

old cocky
Reply to  Nick Stokes
May 7, 2023 3:23 am


Reply to  Nick Stokes
May 5, 2023 3:59 pm

““PRT’s obviously have less thermal mass than mercury max/min thermometers, so will automatically log at least some higher 1 minute temperatures.”

No, it isn’t obvious. You can have as much thermal mass as you like. And they do match them.”

I can’t believe you just wrote that on a science blog.

I propose a $1,000,000 wager on a basic science experiment.

I will have as much thermal mass (as I like) on my thermometer. We will then compare that thermometer to the 1 minute daily highs recorded on the PRT.

The results will not match.

Wanna bet?

Nick Stokes
Reply to  pillageidiot
May 5, 2023 5:48 pm

Unlike bloviators here, the BoM takes measurements and looks at the results. From Trewin’s report
“The lack of any substantial signal in diurnal temperature range at the time of the 1996 transition from manual to automatic weather stations suggests that the automatic weather stations used at that time had similar response time characteristics to the manual instruments which they were replacing.”

old cocky
Reply to  Nick Stokes
May 5, 2023 7:01 pm

Oh, dear

“The lack of any substantial signal in diurnal temperature range at the time of the 1996 transition from manual to automatic weather stations suggests that the automatic weather stations used at that time had similar response time characteristics to the manual instruments which they were replacing.”

Substantial … suggests … similar.
and that’s only for diurnal range.

The report is quite interesting reading. It covers quite a range oif factors which ight have an impact on comparisons, but none in detail.
One thing which stood out is that he also had problems with missing parallel run data, so only reviewed those sites where data had been digitised.

Jennifer Marohasy
Reply to  old cocky
May 5, 2023 9:30 pm

Old cocky, Worse, it only analyses a fraction of the available data for any one site, and it doesn’t even report what it finds honestly. For Mildura the analysis is of the first three years only, not the last three years, which would give a very different and larger difference with one of the newer types of probes.

Last edited 1 month ago by Jennifer Marohasy
Nick Stokes
Reply to  old cocky
May 5, 2023 10:22 pm

Yes. If the response times are similar, the diurnal temperature range should stay the same. If they aren’t it shouldn’t. They do, so that is good evidence.

so only reviewed those sites where data had been digitised”

Of course. He is doing a computer analysis. You can only do that with data that has been digitised, or make the very time-consuming effort yourself, where people had figured that it wasn’t worth the effort (possibly because of missing data).

old cocky
Reply to  Nick Stokes
May 5, 2023 11:34 pm

It’s interesting that Jennifer, you and I have quite different perceptions of the Trewin report.

Jennifer says it should have used all the data, which may not have been available to him in a suitable form

You are saying he used what he had, and near enough is good enough.

I am somewhere in the middle. The report appears to be quite competently done, but it is fairly clear that it’s a preliminary report produced with limited resources (time, staff and data).
It appears that either Dr Trewin took an interest in this area and received approval for an exploratory investigation, or somebody said “Hey, Blair. Have a quick look at how consistent our temperature records have been, will you?”
He found a number of discrepancies, and provided preliminary hypotheses as to their cause.

It is fairly clear to me that there are enough interesting areas of difference to warrant further, more detailed, investigation. For example, the sensitivity to humidity sticks out like a sore thumb.
That could have warranted digitising a further tranche of site records, either the full parallel run period of the sites he covered, or additional sites.

To put it in rather broad terms, he had a quick look to see if anything obvious hit him on the head. There was nothing big, but the smaller things fell into Einstein’s “isn’t that interesting?” category.

Nick Stokes
Reply to  old cocky
May 6, 2023 3:05 am

Blair Trewin lives and breathes this stuff. Kind of a scientific Jennifer. He has looked at enough cases to satisfy him.

old cocky
Reply to  Nick Stokes
May 6, 2023 4:03 am

So it was a “Blair, can you chuck something together?” report.

That inverse relationship with humidity alone is worth a paper.

old cocky
Reply to  old cocky
May 7, 2023 1:07 am

It’s primarily a report on the differences between ACORN-SAT 1 and 2; what changed and why. There were also clearly scope, time and/or resource constraints.

Dr Trewin may live and breathe this stuff, but there are only so many interesting avenues which can be investigated and still have time to eat and sleep.

There were a number of “well, isn’t that intersting?” small effects which may well spawn Masters or Ph.D. projects if the BoM was a more research-oriented organisation.
Digitised data may be available online tp pursue some of these, but some will be dependant on further such data becoming available.

Martin Brumby
Reply to  Nick Stokes
May 5, 2023 9:35 pm

So “suggesting” that something may be “similar”, is “scientific” enough for you to suggest that the other side of this debate is just ‘bloviation’.


Interesting, but not unexpected.

Nick Stokes
Reply to  Martin Brumby
May 5, 2023 10:27 pm

Similar. Within a range. That is all you can ever say in science. It is universal.

Last edited 1 month ago by Nick Stokes
Reply to  Nick Stokes
May 6, 2023 8:27 am

We are government experts, you can trust us.

Jennifer Marohasy
Reply to  Nick Stokes
May 5, 2023 9:25 pm


The ‘Blair Trewin report’ that you link to analyses just the first three years of the 20 years of data available for Mildura. A difference of about 0.2C is reported for that 3 years period which is dismissed as within tolerance.

I found the same about 0.2C difference and it is statistically significant.

For the last three years of parallel data for Mildura the difference is often 0.4C.

Trewin cherrypicked the period of analysis, and even then couldn’t bring himself to report the statistically significant difference.

Like all of the limited analysis done so far by the BOM, it is gaslighting rather than real.

Full marks to Charles for image at the top of this post, with reference to gaslighting.

Last edited 1 month ago by Jennifer Marohasy
Nick Stokes
Reply to  Jennifer Marohasy
May 5, 2023 10:16 pm

I found the same about 0.2C difference and it is statistically significant.”

Again, this dumb talk about statistical significance. Trewin accepted that the difference was 0.2 and within tolerance. You say that more data proves that it was 0.2. So? It’s still within tolerance.

When stations change, the BoM often does a comparison test over 2-3 years. This was done at Mildura, and Trewin reported. Apparently people kept reading after that time, but as you may have noticed, the data was not digitised. So Trewin could not have used it.

Rod Evans
Reply to  Nick Stokes
May 5, 2023 11:26 pm

Your adversarial style is helpful and creates deeper analysis and more considered responses from those who know the subject/detail well.
You rarely win these jousts, but still you climb on your high horse, ready for the next run. I hope that continues, science is about contrarians testing their theories.
I have a question for you.
Why does the BOM hold onto ‘publicly funded’ data? Why don’t they simply release the numbers warts and all? The cost of their delaying tactics, plus the time consumed in being secretive, is pointless. With that being the case, why do they resist being open and upfront with the publicly paid for data they have gathered?

Nick Stokes
Reply to  Rod Evans
May 6, 2023 3:03 am

The BoM releases an enormous amount of data. But that seems to be of no interest here. All people want to do is cheer on Jennifer while she hassles the Bureau. I haven’t seen any serious discussion of what she finds. There can’t be really, because she gives very poor analysis and won’t release the data.

The thing is, she goes after undigitised data. Digitisation is a big deal. It isn’t just the reading and typing, but the layers of checking that the Bureau has to do. And just to satisfy Jennifer’s whims. No-one else is interested in that data.

Reply to  Nick Stokes
May 6, 2023 4:35 am

Digitisation is a big deal. It isn’t just the reading and typing, but the layers of checking that the Bureau has to do. 

Are you for real? You must be taking the piss. You must be joking. You mean the bomb has to some work to give the taxpayer — their – data? You must be a public servant, bureaucrat or other that has never got their hands dirty or done a day’s work. Elite greeny…No question.

Reply to  SteveG
May 6, 2023 6:13 am

..layers of checking? — checking what? Checking, double checking the “data”. Perhaps the bomb should have a reality check.

Nick Stokes
Reply to  SteveG
May 6, 2023 6:45 pm

Work costs money. Other taxpayers pay for Jennifer’s whims.

Rod Evans
Reply to  Nick Stokes
May 6, 2023 7:32 am

The point I am making is, the BoM has ‘the real unadulterated numbers’ they could just let those be constantly and easily available.
Under that strategy, there would be no one ‘hassling’ them as you put it. The only time they would be hassled, is if the actual data does not correspond with their preferred interpretation. Maybe that is what they are really afraid of? Experts able to use the ‘actual’ data might come to a scientifically valid and different conclusion to what BoM is projecting.
Now I can see that could be a problem to the BoM. Maybe that’s why the reluctance to release ‘all’ the data.

The Real Engineer
Reply to  Nick Stokes
May 6, 2023 2:20 am

Nick, you say within tolerance. What do you mean, is there a +- 0.2 C accuracy of the readings? That the repeatability is +- 0.2C? If this is the case you admit there is no temperature change, because you do not have any mechanism to detect it! There is no reason that the PT probes cannot measure to 0.01C accuracy and uncertainty, unless the data logging is also insufficiently accureate and repeatable. The comments on time constants are also very important, glass and PT must exactly match, either electronically or with the same (identical) thermal mass. The way to do this is to mount the PT sensor inside glass, not at all difficult, so looking just like a glass thermometer. I bet that is not how the probes are made!

Reply to  Nick Stokes
May 6, 2023 7:45 am

You seriously think the earth is in peril because of CO2? You really think this? No wonder all your LIKES are well into the RED.

May 5, 2023 3:20 pm

A very comprehensive response to Graham Readfearn. I look forward to seeing part 2. I understand your frustration but I am pretty sure of the motivation for the BOM setting up the barriers to public scrutiny of the comparative temperature data.

Jennifer Marohasy
Reply to  tmatsci
May 5, 2023 9:36 pm

Thanks Tmatsci,

I was expecting to see the Readfearn article in the paper today. But nothing. Small win.

What I wrote as a reply was essentially train of through with some cuts and paste from 4am until 9am Friday morning. That was the time I had.

I had promised to take my 92 year old mother’s car to be serviced at 9am, there is always something. And I had a few other such jobs.

There are a couple of things that need elaborating on, particularly I forgot when I was remembering the Ayer analysis that he only was measuring the last 1 second in each minute against the mercury. The Bom use the highest and lowest one second in each minute for their temperature series, so even Ayer was gaslighting. (Thanks Charles for the great picture at the top of the article.)

Ayer’s analysis is actually not relevant, because he should have been using the highest and lowest one second in each minute not the last if he was testing the Bureau’s method. I’d forgotten the detail. I needed more time to check what I was writing, get some peer review.

Anyway, more to come. But not today.

Last edited 1 month ago by Jennifer Marohasy
Peta of Newark
May 5, 2023 4:13 pm

Here it is Boys & Girls – here is Climate Global Warming Change
h/t to Nick and Blair Trewin

(and perfectly FugAll to do with CO2)

The relevant bit:indicates that minimum temperatures at the new
site are about 0.5 °C lower than the data from the parallel observation period would suggest.

What they’re saying there is that having stuff growing on the ground lowers the temperature by 0.5°C

IOW: The farmers (ploughs and Roundup), the de-foresters, ‘protective’ burners, road, airport and city-builders did it.
They changed The Climate.

Not by emitting CO2, not by growing stuff but because when stuff grew there, stuff died, was consumed by the soil and when it ‘down there’, it retained moisture in the soil

Water controls climate

can peace break out now

Ground Cover Temperatures.PNG
Nick Stokes
Reply to  Peta of Newark
May 5, 2023 6:26 pm

Yes, of course. Temperatures are different in different places. Your image says that there was a period (2008-2010) where the new site did not have established grass

So what did they do about it? From the ACORN station report the new site did not become the primary site until December 2010.

Reply to  Nick Stokes
May 6, 2023 12:21 am

And we know, because BoM told us, that there are about 207 changes due to statistics. So what is the error margin on statistical adjustment? What do statistics say the temperature was yesterday at Brisbane Airport?

Reply to  Nick Stokes
May 6, 2023 7:51 am

You heading to higher land Nick? I mean, 0.2C. Makes me very nervous. Mask up Nick…Mask up! lol

Jennifer Marohasy
Reply to  Peta of Newark
May 5, 2023 9:44 pm

Thanks for sharing, Peta.

Much of the Murray Darling Basin has cooled over the last 100 years because of the introduction of irrigation and more. And so what does the Bureau do, it cools early historical data (pre-1970 etc.) from places like Griffith as part of its homogenisation process in the creation of ACORN-SAT, on the basis irrigation has artificially cooled the environment. And irrigation is not natural.

Using that logic they should actually adjust for AGW, because it’s not natural.

Also, using their logic, they should warm not cool the early years at Griffith. But they are after linear trends of warming, so they mostly just make it up as they go.

More gaslighting. More nonsense.

Last edited 1 month ago by Jennifer Marohasy
Nick Stokes
Reply to  Jennifer Marohasy
May 5, 2023 10:07 pm

on the basis irrigation has artificially cooled the environment. And irrigation is not natural.”
No, that is not the basis. Sets like ACORN are meant to be representative of their region. So if something happens locally which should not be attributed to the region, a correction is made.

Irrigation is local, and would not cool the whole region. So it is adjusted for. In the same way Burketown, with you promoted as an example, had a move from a grassy environment to a dry one. That showed up as heating that should not be attributed to the region, so they corrected to remove it.

AGW, of course is not local. If it affects the station, it will affect the region too.

Reply to  Nick Stokes
May 5, 2023 10:39 pm

AGW, of course is not local.

So why do CCC disciples call it “global” warming?

Is it all getting too confusing for you all, Nick?

Nick Stokes
Reply to  Mr.
May 5, 2023 10:49 pm

So why do CCC disciples call it “global” warming?”

Because it is global, not local.

You’re getting confused.

Ben Vorlich
Reply to  Nick Stokes
May 6, 2023 1:41 am

So Global affects every except when it’s local?

Nick Stokes
Reply to  Ben Vorlich
May 6, 2023 2:19 am

Just as in summer you get hemispheric warming. Doesn’t mean every place warms the same amount every day.

Ben Vorlich
Reply to  Nick Stokes
May 6, 2023 6:51 am

So global except when it’s seasonal, except when it’s hemispherical, except when it’s local, except when you have to think of more weasel words and have to obfuscate some more

Jeff Alberts
Reply to  Nick Stokes
May 6, 2023 7:43 am

It’s not global. But all the averaging and anomalies and averaging of anomalies gives the false impression that all places move in the same direction all the time.

Reply to  Nick Stokes
May 6, 2023 7:53 am

And beneficial…the small change that has ‘perhaps’ occurred.

Reply to  Nick Stokes
May 6, 2023 9:51 am

Yes Nick I was wrong on this premise. My bad.

(However, warming has not been uniformly “global”, but essentially taking place in the northern hemisphere.)

Even Fonzie had his moments –

Reply to  Nick Stokes
May 6, 2023 8:32 am

So, how do you determine what is the local effect and what is the regional effect?
Or do you just pick the one that best supports the position you are paid to support?

Jennifer Marohasy
Reply to  Jennifer Marohasy
May 5, 2023 10:45 pm

Nick, I have the letter from the Bureau back some years now, in response to my analysis of Griffith and Deniliquin, and showing the cooling in response to various irrigation projects coming online. The response was yes, the cooling is artificial because it is from irrigation so we are justified in homogenising.

Nick Stokes
Reply to  Jennifer Marohasy
May 5, 2023 10:50 pm

Can you quote the letter?
But the test is whether the change should be counted as one affecting the region.

old cocky
Reply to  Jennifer Marohasy
May 5, 2023 11:55 pm

Irrigation is an interesting one. Flood irrigation has a different effect to spray irrigation has a different effect to drip irrigation. Similarly, different crops have a different effect – drip irrigated citrus and grapes (and cannabis sativa 🙂 vs drip or flood irrigated rice or centre pivot sweet corn or travelling spray line market garden winter vegetables or summer watermelons.

Irrigation in the MDB has a further complication of reduced water allocations and irrigation coverage during dry spells. Allocation transfers between river systems should have an effect as well.

One would really need to use humidity figures to get a decent idea of the effects of irrigation compared to nearby non-irrigated sites. And, of course, metadata regarding irrigation near the weather stations.

May 5, 2023 4:31 pm

Thank goodness she only had a limited amount of time.

old cocky
Reply to  TheFinalNail
May 5, 2023 4:48 pm

GFY is far more succinct, but rather less informative.

old cocky
Reply to  TheFinalNail
May 5, 2023 5:58 pm

or perhaps she’s like Blaise Pascal, and didn’t have time to make it shorter.

Jennifer Marohasy
Reply to  old cocky
May 5, 2023 9:53 pm

Thanks Old Cocky, I didn’t have time for reflection or shortening. It was mostly just a case of getting enough down on different related and relevant topics, as train of thought.

Last edited 1 month ago by Jennifer Marohasy
Reply to  TheFinalNail
May 6, 2023 7:56 am

MASK UP! Tinfoil hat works pretty well I’m told too.

Reply to  cosmicwxdude
May 6, 2023 8:35 am

It’s not like there was anything in the post that could actually be criticized.

Reply to  TheFinalNail
May 6, 2023 8:35 am

So you prefer the government’s method of only giving the information that supports your position?

May 5, 2023 5:10 pm

Some years ago now, young Mr. Readfearn took on Christopher Monkton in a climate debate onstage in Brisbane, Australia.

It was reported that young Readfearn left the stage in tears.

Maybe Christopher can recount this tale for us?

May 5, 2023 5:13 pm

My favorite response by someone refusing to release raw data – “It isn’t a question of just providing you the raw data. It also depends on how the data is nuanced to produce the correct results that is at issue.”

Martin Brumby
Reply to  ScienceABC123
May 5, 2023 9:40 pm


And there to see in Climategate, better to destroy data that to allow anyone to see it.

Must warm the cockles of Nick Stokes’ little heart.

May 5, 2023 5:47 pm

God bless you Jennifer, for keeping your cool and responding in an unemotional way.
If it was me, I’d be going “John Wick” with a pencil🙃

Jennifer Marohasy
Reply to  schmoozer
May 5, 2023 9:49 pm

Thanks Schmoozer. I can’t afford to rest or get too emotional.

Eventually we must win through and with logic and as truth seekers. :-).

Reply to  Jennifer Marohasy
May 6, 2023 3:43 am

Eventually we must win through and with logic and as truth seekers. :-).

Yes, 100%. —

“The truth is incontrovertible. Malice may attack it, ignorance may deride it, but in the end, there it is.” —Winston Churchill, former Prime Minister of the U.K.

Tom Abbott
May 5, 2023 6:16 pm

So the unmodified temperature data for Amberley (in figure 2) shows a cooling trend. In other words, it was warmer in the past than it is today even though there is more CO2 in the atmosphere than there was in the past. One would have to conclude that more CO2 does not equal higher temperatures.

And the bastardized version of the chart after data mannipulation, shows a warming trend.

I think you will find this is the case with most comparisons of this kind.

The Data Manniplators have been hard at work turning a cooling trend into a warming trend.

They are making things up, and destroying Western society in the process because of the Big Lie.

The Big Lie = The claim that the human race is currently experiencing unprecedented warming caused by CO2. But there is no unprecedented warming if you go by the unmodified temperature charts from around the world because they show, like Amberley does, that it was just as warm or warmer in the Early Twentieth Century than it is today, when you go by the actual data.

Hang in there, Jennifer. As Rud said, you are over the target and that’s why you are getting th flak. Alarmists don’t like their comfortable little, got-it-all-figured-out world, upset with facts.

Martin Brumby
Reply to  Tom Abbott
May 5, 2023 9:44 pm

And, if I might be permitted a bit of my very own “bloviation”; the Grauniad, BoM, Redfearn and Stokes have proved themselves, many times, to be as trustworthy as sh1thouse rats.

Reply to  Martin Brumby
May 6, 2023 1:07 pm

1000%. Naive ‘followers’ of the cult.

Jennifer Marohasy
Reply to  Tom Abbott
May 5, 2023 9:51 pm

Thanks Tom, And to better understand what has happened to the Amberley data read all my notes from that Sydney Institute presentation, they are here:

Dave Andrews
Reply to  Tom Abbott
May 6, 2023 8:34 am

In 1976 John Gribbin, an assistant editor of Nature *, published a book entitled ‘Forecasts, Famines and Freezes’ The following quotes are from pages 7 and 8

“From the 1890s right through to the mid 1940s, with only a slight dip around 1905, the global air temperature increased. Altogether this increase amounted to about half a degree C”

“Between the mid 1940s and 1970 global mean temperature fell by about one third of a degree C; for the five year period 1968 – 72, the average temperature recorded by the nine ocean weather ships which are stationed between 35 and 66 degrees N was more than half a degree C below the peak of the 1940s and this local cooling continued in 1973. In worldwide terms, we are in a situation where the Earth is cooling more quickly than it warmed up earlier in this century”

“What does this mean in local terms? Taking an average of the figures for England alone, the decade of the 1960s was about one third of a degree C cooler than the average for the preceeding thirty years.”

(*Note this was from an era when Nature was considered to be one of the foremost scientific publications in the world)

Last edited 1 month ago by Dave Andrews
Tom Abbott
Reply to  Dave Andrews
May 7, 2023 4:21 am

Here is the unmodified U.S. surface temperature chart (Hansen 1999):

comment image

As you can see, the temperatures from the 1910’s to the 1930’s increased by about 2.0C, and then the temperatures cooled by 2.0C from the 1940’s to the 1970’s, and then the temperatures again warmed from the 1980’s to 1998 at about the same rate as it did during the 1930’s, although not quite reaching the high temperatures of the 1930’s. Hansen said 1934 was 0.5C warmer than 1998, and that makes 1934 warmer than 2016, too, 2016 being the warmest temperature in the satellite era (1979 to present), being 0.1C warmer than 1998.

So John Gibbon didn’t quite get the magnitude of the temperature changes for the period he referenced, going by the U.S. temperature chart.

Dave Andrews
Reply to  Tom Abbott
May 7, 2023 7:12 am


I’m aware of Hansen and his later manipulation of the US record and of your chart.

I was using Gribbin as another example of the early 20th C warming ( unfortunately there are no reference notes in the book so I can’t give any more detail) just like I often post about the open season at the coalport in Spitsbergen (Svalbard) going from 3 months of the year before 1920 to over 7 months of the year by the late 1930s.

The warmunistas have adjusted away the early 20thC warming.Lets return it to its rightful place!

May 5, 2023 10:29 pm

Very nice Jennifer, you have more guts than me. Always remember you are dealing with liars and cheats, don’t expect any respect from them. They will say and do anything to cover their own backside. Kudos to you.

Jennifer Marohasy
May 5, 2023 10:39 pm

Thanks so much to Anthony Watts and Charles Rotter for republishing this rebuttal letter, and for the continued support I get from It means a lot.

I did write the rebuttal as mostly ‘train of thought’ with some ‘cutting and pasting’ of what was at hand, on Friday/yesterday morning between 4am and 9am. I wasn’t given enough time, and I had other obligations, etcetera.

On reflection there are two issues that need elaborating on:

1.John Abbot asked for the Brisbane data because some years ago, and then every so often again, I get focused on wanting to create a temperature index for Brisbane. I was born in Darwin, and sent to boarding school in Brisbane. Those two cities mean a lot to me, they are part of who I am. Back when I was last playing with Brisbane Regional Office data from the ADAM database (the green line in Chart 1), I understood this entire series had been recorded at the one location. Lance Pidgeon has previously alerted me to site moves, but I haven’t taken the time to properly understand the implications. Meanwhile, the official Bureau chart for that location is attached.

2.It is Bill Johnson, amongst others, who have ran a campaign for some months accusing me of harassing the Bureau and citing Greg Ayers as proof there is nothing to see, that I am wasting time/the proof of equivalence is already in. So the Greg Ayers’ peer reviewed journal article has been discussed at length here at WUWT, and in other forums, including by Lance Pidgeon, who I spoke with earlier today. And I now remember that it is disingenuous of Ayers to use the probe data that he did as a comparison with the mercury to test equivalence, because the Bureau use the highest one second from each minute, not the last (Ayers used the last second in each minute). I should have mentioned that in my rebuttal letter, but I forgot. It is an important technical detail, and it must be annoying to some (Lance especially) that I forgot that important point. I was rushing and flicking and not seeing or at least not registering Greg Ayers’ very upfront/but also deceptive mention of using the last one second as his point of comparison. (The art of gaslighting.)

I really want to find the time to get back to more analysis of the Brisbane parallel data, and to reread Greg Ayers and think again.

We are much less susceptible to ‘gaslighting’ when we are not under a time pressure, and other pressures.

There is always more than one way to cut the data, and always more than one statistic that can be reported. Greg Ayers was gaslighting to have got us all focused on the last one second, when it is actually the highest one second and lowest one second that is the statistic reported by the Bureau and entered into the ADAM database.

When I did the initial analysis of the Brisbane data over Easter/a month ago, and passed it to Graham Lloyd at THE AUSTRALIAN he was immediately interested, and wanting me to simplify the statistical analysis further. (While my instinct was to get more complicated.) Graham Lloyd suggested (and correctly so) that we mention the percentage of recordings that were hotter, cooler and the same as the probe. This is the type of plain English explanation that most people can understand.

In my reply to Graham Readfearn (republished above), I make it even simpler, and mention that contrary to what Greg Ayers’ reported, most of the daily probe recordings were at least 0.1C away from the mercury, and many 0.2C and I should have mentioned some as much as 0.7C away.

Friday morning as I drafted the rebuttal, I was looking again at my original statistical analysis (n=1094) for all the daily differences and for those interested, the standard deviation of the paired difference is 0.19C (p=0.003).

Nick Stokes
Reply to  Jennifer Marohasy
May 5, 2023 10:57 pm

for those interested, the standard deviation of the paired difference is 0.19C (p=0.003).”

The graph is not of the difference, but just a temperature series of one instrument.

You seem to be able to quote lots of statistics of small relevance (what does p=0.003 mean here?), but still no accurate estimate of the mean difference.

Jennifer Marohasy
Reply to  Nick Stokes
May 6, 2023 12:45 am


I’m referring to the paired differences in Chart 3 of the rebuttal letter, the daily Brisbane data.

The chart is Tmax annual data for Brisbane, that I also make comment about.


Bill Johnston
Reply to  Jennifer Marohasy
May 6, 2023 4:34 pm

Jennifer’s storyline is becoming increasingly more confused.

She first requested parallel data for Wilson’s Promontory lighthouse in August 2015. However, had she studied site-summary metadata she would have found (like I did), that thermometers were removed on the same day the automatic weather station was installed. It was a similar story for Rutherglen and Cape Otway, and for many other sites, including Bureau-operated sites, some of which are Australian Climate Observations Reference Network – Surface Air Temperature (ACORN-SAT) sites. Gunnedah as I’ve pointed-out is still a manual site.
Jennifer also mistakenly believes that “Bureau policies” relating to site and instrument changes are enforceable on organisations that cooperate with the Bureau by supplying data. In the main these were state government orgaisations including Parks Victoria, the Department of Primary Industries Victoria (and New South Wales), NSW National Parks and Wildlife Service in respect of the weather station at Thredbo, operators of licensed post officers, and private operators including the now-closed site at the at the Charlottes Pass Chalet. Lighthouses were never operated by the Bureau. The ACORN-SAT site at Gunnedah was originally run by the Soil Conservation Service of NSW and for some years has been operated by a BoM contractor.  
However, she is wrong. The Bureau of Meteorology is a commonwealth organisation and there is no compulsion for non-Bureau sites to be bound by “Bureau policies”. Jennifer never corrects the record or admits to being ill-informed, especially if she herself failed to do her homework.
The issue of probe verses thermometer sensitivity has also been kicked around seemingly forever. While there is evidence that PRT-probes are prone to spiking (which as a result of work I did in the 1980s, I alerted her and others to, over a decade ago), as explained in publications, the Bureau’s automatic weather stations use error-trapping at source to minimize the effect of spikes. In my view, excluding a spike is more effective than averaging across a spike.   
The probes used by the Bureau (for which there ARE pictures in publications) were developed in their NATA-certified metrology lab in association with manufacturers, specifically to mimic the response time of glass thermometers. The lab is (or was) run by Dr Anne Warne (who now may be retired).
The paper published by Ayers, G. P. (2019): A comment on temperature measurement at automatic weather stations in Australia. Journal of Southern Hemisphere Earth Systems Science 69, 172–182 https://doi:10.1071/ES19010), and Ayers G.P. and Warne J.O. (2020): Response time of temperature measurements at automatic weather stations in Australia. Journal of Southern Hemisphere Earth Systems Science, 2020, 70, 160–165, are sufficiently comprehensive to have put the probe issue to rest.

By continuing to raise it as hot news, and quoting an analogue engineer who has a theory about radio interference but has no data to back it up, Jennifer embarrasses herself.
As explained by Ayers and Warne, response times have been lengthened so that an end-of-minute value is attenuated over the previous 40 to 80 seconds. It is therefore NOT spot-value as Marohasy believes, but an attenuated value. She could find out about this if she spent more studying the issue rather than hand-waving about it and listening to whispers from mysterious “analogue engineers”.
Furthermore, thermometers and PRT-probes collocated in the same Stevenson screens DO NOT sample the exact same parcels of air, and therefore CANNOT be expected to provide precisely the same values.

As these discussions have evolved, it is increasingly clear that Jennifer does not understand the concept of sampling error. Looked across (rather than lengthwise), the data for Brisbane shows a sampling distribution that is ‘tight’ overall. There are four values less than 0.5 degC (two hidden under the word red), and four values that exceed 0.5 deg C, but aside from the step-change there is nothing peculiar or sinister about a couple of outliers. If she had experience in undertaking weather observations and checking field books like I have, she may better understand what to expect when examining data 3rd hand.
Also, a chart of differences cannot show whether it was the probe or the thermometer that was responsible for outliers on those eight out of possibly 3,000 days. The step-change is different issue, which I have discussed before on WUWT. I have also previously discussed the issue of instrument and observation uncertainty, which she does not seem to grasp either.        
Homogenisation is not remodeling. It is a subject that I have reported on at, where I will continue to point out flaws in the Bureau’s methodology on a case-by-case basis. While there is a case to adjust temperature records, Jennifer is wrong to analyse data, inclusive of site change effects, using naïve linear regression.
Like she has previously said for Ruthergen, temperatures at Amberley were not “correctly measured in the first place”. They were measured at a range of locations, using a range of instruments, by RAAF Aeradio as well as Bureau staff. It is inappropriate to use naïve methods to determine trend and change on data that are not homogeneous, and even worse to go data-shopping using Excel (see:, and the attached report.)  
To be clear, I am not a fan of the Bureau, or of the Bureau’s homogenisation methods. However, it is important to pick winnable fights, not start or prolong just any fight.
I am even less a fan of The Guardian and in particular fake-news editor Graham Readfearn, who seems incapable of writing objectively or with an eye to both sides of a story.       
Yours sincerely,
Dr Bill Johnston

May 6, 2023 12:54 am

The Guardian!

It ceased to be a newspaper years ago and turned into the house organ of the UK Labour Party. Or probably in Australia its equivalent, if there is one.

It doesn’t think of its mission as reporting the news, but as changing the world. And so we get the facilitation of Snowden’s flight to Russia, the employment of people like Richard Gott and Seamus Milne. And the endorsement of Corbyn’s Labour at the last general election. A once liberal paper endorsing a coterie of anti-Semitic Trotskyites and terrorist sympathizers. The consistent refusal to report on the Northern grooming and child abuse scandals. And of course that ludicrous style guide, in which we are no longer to hear about global warming, but only global heating, and the word ‘climate’ is never to be used except when followed by ‘crisis’ or ’emergency’.

Even more ludicrously, all this is promoted as ‘independent journalism’.

Lately they have finally discovered to their horror that their paper had taken the wrong side during the American Civil War. Had denounced Lincoln. This interrupted the continual stream of pieces mixing slanted reportage and denunciation of everyone in sight. Suddenly they noticed to their horror a beam in their own eye. They were about the last to notice it. Don’t worry, it won’t last.

C P Scott has been turning in his grave for decades now.

Reply to  michel
May 6, 2023 1:00 am

I forgot to mention the Clark County affair, when they asked their readers to write to the voters of Clark County and ask them to vote for Kerry against Bush. How utterly ludicrous was that? Even assuming its the Guardian’s role to start trying to influence US elections rather than report them, the idea that its intervention could have a positive effect for Kerry was just hallucinating. As the BBC reported at the time, it may have actually helped Bush!

Dave Andrews
Reply to  michel
May 6, 2023 8:53 am

Seamus Milne left to join Jeremy Corbin’s team when he became Leader of the Labour Party. Not sure what he is doing now. Do know that for many years he wrote essentially the same article, carried in the centre pages, attacking the US over anything.

May 6, 2023 1:09 am

I took daily readings for the UK met office for 20 years so can relate to the homogenisation…..
The readings (max, min, wet dry temp, various ground temps, rainfall) were taken at or around 9am (10am in BST) but could be taken up to an hour either side of 9am. Once the data was sent, it was adjusted for instrument calibration and ‘human error’ and added to other regional data, where it was averaged and rounded up. On occasions that certain data couldn’t be got (missing or broken instrument) it was infilled by the regional office using raw data from elsewhere, usually about 15 miles away from the site I used.
Far too much opportunity for manipulation.

Tom Abbott
Reply to  mrbluesky
May 6, 2023 4:19 am

“Far too much opportunity for manipulation.”

And the climate alarmist data mannipulators are using it to their advantage.

The raw (unmodified) data shows cooling. The data, after bastardization, shows warming. Just what climate alarmists want to see. It doesn’t exist in reality, so they make it up using their computers.

It’s criminal, considering the detrimental ramifications to society.

Reply to  mrbluesky
May 6, 2023 4:54 am

And how exactly do you adjust for human error.

Which of the following numbers is wrong and needs adjusting?

12, 13, 12, 14, 12, 12, 12, 12, 12

How is it possible for someone, (remote from the source), to say that I type a wrong number? And then have the ability to change it.

Reply to  Eng_Ian
May 6, 2023 1:17 pm

I’m sure Nicky the Stroke has an answer for you.

May 6, 2023 1:13 am

The bomb is an advocate of CAGW. That is all one needs to know to understand the “accuracy” of the “data”.

May 6, 2023 8:17 am

As Nick has carefully explained. The government has decided what information you need.
That should be enough to put the issue to rest.
As every good lackey knows, the government cares for you and is never wrong.
If that doesn’t settle the issue, you are probably some form of anarchist and need to have a visit scheduled with Camp 37 where you will be re-educated and have your attitude adjusted.

Jennifer Marohasy
May 6, 2023 7:39 pm

The Guardian have published the article this morning.

I have drafted Part 2, and will finalise it after I’ve taken my mother to lunch.

The key information, to begin with, is perhaps:

It is my contention that the Bureau is only transcribing a tiny fraction of the parallel data, and analysing a still smaller component, because proper scrutiny of the entirety of it will show that the resistance probes hooked up to the data loggers are producing readings that are not fit-for-purpose.   Certainly, there is no equivalence between the readings from probes and mercury considering the limited amount of data that I have wrangled to date.  

The Bureau claims otherwise while carefully avoid any mention of statistical significance – the usual measure of whether two means (the average temperature from the probe compared to the average temperature from mercury, for example) are equivalent, or not.  

In the case of Brisbane Airport, today’s article in The Guardian quotes the Bureau claiming the mercury at Brisbane Airport was on average within 0.02C of the automatic probe across three years.   

I get the same result, across the three years.   This overall mean difference is small because there is an abrupt change/discontinuity in the direction of the difference after January 2020, with the readings before January 2020 showing the mercury recording warmer and the readings after January 2020 showing the probe recording warmer.  The difference balances out mathematically, while the discontinuity creates havoc if one is interested in climatology and the integrity of long continuous temperature measurements to feed into a statistical model underpinned by AI. 

The overall difference (across the three years for Brisbane Airport) is statistically significantly different (n= 1094, p = 0.003, standard deviation = 0.18).  The readings from the probe relative to the mercury are all over the shop: that is, they show significant scatter and it is not random. 

My analysis of the three years of parallel temperature data from Brisbane Airport shows that 41% of the time the probe is recording hotter than the mercury, and 26% of the time cooler. To reiterate, the difference is statistically significant (paired t Test, n = 1094, p < 0.05). The differences are not randomly distributed, and there is a distinct discontinuity after December 2019.

I initially thought that this step-change from an average monthly difference of minus 0.28C in December 2019 to plus 0.11 in January 2020 (a difference of 0.39C) represented recalibration of the probe.

The bureau has denied this, explaining there was a fault in the automatic weather station that was immediately fixed and operating within specifications from January 2020 onwards. Yet even after January 2020, the probe was recording up to 0.7C warmer than the mercury thermometer at Brisbane Airport.

A 0.7C difference is enough to generate more record hot days for the same weather, supporting the narrative of the new King that the planet risks overheating.  

Bill Johnston
Reply to  Jennifer Marohasy
May 7, 2023 2:15 am

But it was not a 0.7 degC difference, it was a single outlier that was seemingly matched by a negative outlier. You make a habit of making hugely misleading statements then duck into the change-room.

Don’t be such a petal. Stop the pain by placing your data in the public domain like I do on

Kind regards,

Dr Bill

Jennifer Marohasy
Reply to  Bill Johnston
May 7, 2023 1:43 pm


You really are proof that there are a lot of unkind people in the world, and who despite their significant knowledge of a subject area, would prefer to obfuscate and mislead.

You can easily see from Chart 3 (above) that the values of 0.7 are not outliers.

I did exclude two data points from the analysis because they were outliers. One of those generated a difference, from memory, of 3.3C.

Last edited 30 days ago by Jennifer Marohasy
Bill Johnston
Reply to  Jennifer Marohasy
May 7, 2023 6:01 pm

Two values outside the best-bet bandwidth of comparing two values (which is 0.6 degC) out of a thousand or so, makes them outliers by definition. There is no kindness or unkindness in pointing that out.

Out of kindness I have sent you a private email outlining problems with using paired and unpaired t-tests on autocorrelated data, using data for Townsville airport as a case study, and why paired t-tests are probably not valid in this case. Please step-back and take the time to read it.

As I have said repeatedly, stop the pain by placing your data in the public domain like I do at

Yours sincerely,

Bill Johnston

Nick Stokes
Reply to  Jennifer Marohasy
May 7, 2023 1:53 pm

today’s article in The Guardian quotes the Bureau claiming the mercury at Brisbane Airport was on average within 0.02C of the automatic probe across three years.  “

So it took the Guardian to get for us that basic piece of information that Jennifer had been not telling us for weeks (after claiming that it was 0.15 at one stage).

Post the data!

Jennifer Marohasy
Reply to  Nick Stokes
May 7, 2023 3:59 pm

Hey Nick

I think that value came from the Bureau, not the Guardian. They should post all the data, with the two outliers that I assume they haven’t included in their calculations either.

The Bureau should post not just three years, but all days for all 15 years that they hold.

May 6, 2023 8:13 pm

The article of climate idiocy has now been published.

Alas the comments are full of the normal level of Guardian conspiracy ideation coupled with bed wetting and deep insights such as:
“This morning the heater was turned on for the first time this year. Fifty years ago that heater was burning for the last half of April. That’s three weeks of change.”

The comments section was closed after about 3 hours – sadly not because of some new found self awareness and embarrassment – a large number of comments seem to have been moderated/censored. Given the normal state of commentary at the Guardian typically never climbs above the sorts of things you might find scrawled on a poorly maintained public bathroom wall it’s hard not to perceive this a attempting to present a false balance.

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