A science presenter, writer, speaker & former TV host; author of The Skeptic's Handbook (over 200,000 copies distributed & available in 15 languages).


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The Conversation — cleansing skeptical thoughts — Read the banned comments here

The Fake Conversation where Bill’s informative, polite comments are removed, but the replies are left there.

Last week Bill Johnston posted a detailed, comprehensive analysis of Sydney Observatory thermometer record here that shows that most of the warming recorded there is due to buildings and freeways. But photo’s and graphs are “denier” stuff, and The Conversation is so afraid some its readers might see those historic photos they ban links to Bill’s work and Apparently when the Bureau of Meteorology discusses “Australia’s hottest decade” it is off topic to discuss the condition of their thermometers.

Bill Johnston was happy to defend his work in comments at The Conversation, but Blair Trewin, who wrote the post itself, was entirely absent. Cory Zanoni had to close the dangerous thread. He removed scores of comments, but left replies to Bill Johnston intact. Some “conversation”.

At least 46 of Bill Johnston’s comments were deleted from Australia’s climate in 2016 – a year of two halves as El Niño unwound   and 19 deleted from Australian climate politics in 2017: a guide for the perplexed. As Bill says: They obviously want to stay perplexed; uninformed; scary-cats, without a paddle for their leaky canoe.

Some skeptics [...]

Sydney Observatory where warming is created by site moves, buildings, freeways

The iconic Sydney Observatory is Australia’s longest running weather station. But everything around the site has changed. Bill Johnston has spent months researching, photographing, and hunting through historic files to document those changes. He wasn’t paid for this work, but what he found was that the BOM has missed that the area around the thermometers has changed dramatically over the last century, so much so, that he claims it’s scientifically meaningless to try to construct climate trends from this data. Aerial photographs show exposure of the instruments changed in 1950, when Stevenson screens were moved, and after a brick wall was built metres from the screen in about 1972. It is suspicious that the changes are undocumented in Bureau reports, especially given they are responsible for much of the “unprecedented warming” in Sydney’s temperature data.  The BOM may counter that this site is not used to calculate warming trends across Australia, but as Bill points out, Sydney Observatory is used to homogenize other sites that are. So site changes and the urban heat island effect infects many country sites, and the traffic in Sydney “warms the nation”.  — Jo


Its fake news week! Guest post by Dr. Bill Johnston[1]. [...]

BOM September failure — but who can predict the climate a whole month ahead?

The World’s Best Practice climate models predicted Australia would be hotter than normal in September, instead the maximum temperature anomaly was 1 to 5 degrees below average across most of Australia.

That long range prediction was made all the way back on August 21. Four weeks later it was obvious it was wrong.

Prediction of a hot September versus actual outcome. (Click to enlarge).

Thanks to Warwick Hughes who saw this failure coming and The Marcus Review who points out the mismatch and goes on to log how much the BOM predictions for October have transformed from hotter than average to cold cold cold.

The BOM bravely predicted Tasmania would have an 80% chance of having hotter than average maximums. Temperatures ended up being spot on average. What’s 80% certainty worth? About the same as 95%.

Thanks to Chris Gillham who pointed out the big cold blob of ocean surrounding Australia on the south and west that gave Perth its coldest ever September nights. Wasn’t that cold blob present on August 21 when those models were run? On August 25th, the BOM predicted Perth’s chances of being cooler than average at 50:50. Toss a coin, or use a climate [...]

Coldest Perth September recorded in 120 years of records (must be climate change)

In the last 120 years in Perth there has never been a September as cold as this one. We know that thanks to Chris Gillham, who has been tracking Western Australian weather in detail for years at

The headline in The West Australian today was Perth shivers through it’s coldest ever September. For some reason (I can’t think why) the extreme weather journalists did not mention climate change (has that ever happened on a hottest ever record story?). It’s so unusually cold here that wheat farmers, only weeks away from harvest*, are struggling with frost damage on crops. They are making snowmen from the frosts. It is supposed to be rapidly heating up but it is three degrees below normal.

Given the freak weather, Will Steffen immediately announced that “This is a prelude to a disturbing future. And it’s only going to get worse if we don’t address climate change.”  No. Wait. Scratch that. That was South Australia, where one bad storm was caused by coal fired electrons. A record cold month is just weather.

Curiously, The Bureau of Meteorology(BOM) announced it was the coldest ever September for Perth since 1994 when records started at Mt Lawley, and [...]

Australian temperatures unchanged for 20 years: Plus Malcolm Roberts first Senate speech is tomorrow

Malcolm Roberts will give his maiden Senate speech tomorrow (Tuesday) at 5pm at the Australian Parliament House in Canberra. To reserve seating contact Leon Ashby leon.ashby AT or phone (02) 6277 3151. He has asked for updated graphs of the UAH data for Australia. His speech may be available via the APH website. (h/t Jim S)

Luckily for us the UAH satellite database can be filtered to track temperatures in the lower troposphere over the Australian land mass. Thanks to John Christy for providing an Australian specific dataset.

We’ve put out a third of all the CO2 homosapiens has ever made in the last 20 years, and it apparently has made no meaningful difference to temperatures here. We’ve put out 60% of all our CO2 since the satellite record began.

Here is the full Australian monthly data from 1979 – now for all seasons graphed below. There are breathless news articles hyping every hot month, every hot week, for records in every little region, and even for a single record hot nights, but no press release to say that temperatures in Australia have not really changed in a meaningful way since 1995.

Thanks to  KensKingdom [...]

Met Bureau Bingo: warm autumn nights sold as “Hottest Ever” March extreme

It’s another month of BOM Bingo. The ABC and BOM are trumpeting a “hottest” ever headline yet again, and Warwick Hughes is onto them already.

Conveniently the ABC forgets to mention that March Maximum Temps have been hotter before many times and with a pattern that has nothing to do with CO2. How many in the ABC audience would know that?

March temperatures sets record as hottest ever, Bureau of Meteorology says

“You could be forgiven for not noticing the end of summer — March was a hot one.” says Sara Phillips. But actually, if you are human, you could be forgiven for thinking this was just another hot March like so many before. For SE Australia where most humans live, the hottest March, and wildly so, was in 1940. Across the whole of Australia these kinds of maximum temperatures in March have been occurring for decades and 1986 was much much hotter. See the BOM graph below.

Hands up who can spot the horrid effect of CO2 in this graph?

Stick with the logic. Must be CO2 that caused the cold spike in 2011 (and 1967, 1942 and 1913). This is witchcraft.

You could be forgiven [...]

Blockbuster: Are hot days in Australia mostly due to low rainfall, and electronic thermometers — not CO2?

Blame dry weather and electronic sensors for a lot of Australia’s warming trend…

In this provocative report, retired research scientist Bill Johnston analyzes Australian weather records in a fairly sophisticated and very detailed way, and finds they are “wholly unsuitable” for calculating long term trends. He uses a multi-pronged approach looking at temperatures, historical documents, statistical step changes, and in a novel process studies the way temperature varies with rainfall as well.

His two major findings are that local rainfall (or lack of) has a major impact on temperatures in a town, and that the introduction of the electronic sensors in the mid 1990s caused an abrupt step increase in maximum temperatures across Australia. There will be a lot more to say about these findings in coming months — the questions they raise are very pointed. Reading, between the lines, if Johnston is right, a lot of the advertised record heat across Australia has more to do with equipment changes, homogenisation, and rainfall patterns than a long term trend.

Bill Johnston: On Data Quality [PDF]

“Trends are not steps; and temperature changes due to station changes, instruments and processing is not climate change”, he [...]

Camouflage illusions in the matrix: same mysterious temperature, same day, year after year

Wait til you see what Lance Pidgeon has found. He was looking at the BOM website temperature archive maps of Australia for early last century (using AWAP data). He was wondering how the Bureau of Meteorology could possibly create maps this detailed for specific days that long ago. He was especially curious about the remote, vast areas where there were no thermometers, yet there were wiggly jiggly temperature lines on the map, shaded as if they had meaning. I’ve heard that more people have visited the South pole, than have stood at the point in central Australia where the three large western and central states meet.

Then he noticed something positively strange — April 14th in 1915 and one year later in 1916 looked almost identical, as did the same day in 1917. The more he looked, the weirder things got. He plodded, year after year, all the way from 1911 to 1917, then through Jan, Feb, March, and so on.  Worse, he tells me he could keep going right through to 1956 without seeing much change (though there are interesting exceptions). After that, temperatures of the area start to vary from year to year, like the “weather” we’d expect if we [...]

Rent-seekers reveal awful truth: Abbott wanted to investigate BOM data, Hunt opposed “due diligence”

Imagine the crime of trying to audit the BOM?

Last year, Graham Lloyd wrote in The Australian about how the BOM had made whopping two degree adjustments to data which turned cooling trends to warming trends and instead of improving the data, it created discontinuities. The BOM’s eventual explanation lamely exclaimed that the stations “might” have moved. (And they might not, too. Who knows, but remember this is what 95% certainty looks like.) Lloyd wrote about how historical records of extreme heat at Bourke had effectively been thrown in the trash. Who cares about historical records?

In response to the embarrassment and revealing questions, Tony Abbott wanted an investigation.  But Greg Hunt, and The Dept of Environment opposed the investigation and opposed doing “due diligence”. What are they afraid of? Instead, Hunt helped the BOM set up a one-day-wonder investigation with hand-picked statisticians that wasted another nine months before admitting that the BOM methods would never be publicly available or able to be replicated.  If it can’t be replicated, it isn’t science.

The BOM’s defense is always that their mystery method is considered “best practice” by other agencies around the world — who share the same incentives to exaggerate warming, [...]

Scandal Part 3: Bureau of Meteorology homogenized-the-heck out of rural sites too

The  Australian Bureau of Meteorology have been struck by the most incredible bad luck. The fickle thermometers of Australia have been ruining climate records for 150 years, and the BOM have done a masterful job of recreating our “correct” climate trends, despite the data. Bob Fernley-Jones decided to help show the world how clever the BOM are. (Call them the Bureau of Magic).

Firstly there were the Horoscope-thermometers — which need adjustments that are different for each calendar month of the year – up in December, down in January, up in February… These thermometers flip on Jan 1 each year from reading nearly 1°C too warm all of December, to being more than 1°C too cold for all of January . Then come February 1, they flip again. Somehow the BOM managed to unravel this bizarre pattern (cue X-files music) and figure out exactly what anti-horoscope-adjustments to use (and they were different in every city). Modestly the BOM did not explain to the public how clever their adjustments were; despite their $300m budget, it took volunteer Bob Fernley-Jones to reverse out the Special Horoscope Cure, and find the square wave algorithm that repaired our damaged climate records. Lucky for the [...]