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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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 [...]

Let’s play BOM Bingo, and turn every heatwave into a media scare-fest

Despite the headlines, there was no paranormal extreme in Perth last week — just a game called heatwave bingo

Perth set a sort of record last week for four days in February above 40C. The BOM and media paraparazzi glorified the latest heatwave, chasing it like it was a celebrity Kendall-Jenner-type-event when it was not that different to the heatwaves we’ve had before. Before it came, there were headlines about how it was coming, there were minute-by-minute graphs of degrees C, stories of people cooking cupcakes in hot cars, and there were projections  about hypothetical bigger, longer heatwaves that might come, maybe one day, someday: look out for “Temperatures into the fifties”!

Chris Gillham points out that this record was made at the Perth Metro station. Few seemed to mention that 9km away, at Perth Airport similar kinds of heatwaves were pretty common and things had been hotter and lasted longer in years gone by. This year the four day average at the airport was 42C but in 1956 there were 5 days at an average scorching 43.7. In 1933 there was a six day heatwave of 42C average in Perth city. And there were other heatwaves a lot like this a couple of weeks earlier, [...]

Two-thirds of Australias warming due to “adjustments” — according to 84 historic stations

1954 Yearbook Brisbane

Here’s an update to the digging through our historic records we discussed a month ago, we can now include nearly twice the stations and the difference between temperatures originally recorded 100 years ago and temperatures today are even smaller.

Chris Gillham has been working with CSIR documents and official Commonwealth Year Books. Last month he used the 1953 Year Book which contained 44 weather station averages for 1911-40 to compare with 2000-14 temperatures, but has since discovered that the 1954 Year Book provides an additional 40 stations with 1911-40 data. The average rise in mean temperatures across all 84 weather stations around Australia over the last 70 years of global warming is about 0.3C. This larger dataset suggests as much as two thirds of the current official trend in Australian warming was due to post hoc adjustments, not heat recorded by thermometers.

These historic temperatures were calculated by the best scientists of the day, using the best equipment of the era (the same Stevenson Screen we use now). Yet again, global warming appears to have a “man-made” contribution. Far more important than CO2 is man-made “pollution” called homogenisation.

When doubling the recorded trend makes “No difference”

Bear [...]

Mystery black-box method used to make *all new* Australian “hottest” ever records

There were not many long term sites (in black dots) in the centre of Australia in 1930.

This summer the Bureau of Meteorology (BOM) invented a whole new metric to measure average national heat, which might be all very well except no-one (other than the BOM) seems to know what it is.

On January 7th the BOM claimed Australia set a new “average maximum daily temperature record”. Now the headlines are about the “hottest” Australian summer.

With both records, no one outside the BOM team has access to the methods or data. This post is about the new “daily” temperature of Australia used to declare Jan 7th was a record, but the same point applies to the “hottest summer” records, even though they may be a different data set. Where is the data? Where are the methods?

Is the BOM a science agency or a PR bureau?

The January 7th heatwave supposedly broke all previous “daily” records in this category — a dubious honor since no-one can remember any records like it.

It’s a bit like winning the Side-Jump. It’s not an event anyone knew was on until the medal ceremony. Worse, no one knows how the [...]

Cherry-picking sea level rises in Perth (a city which happens to be sinking)

“Gale Force” cherries coming your way…

Two weeks ago, it was all over the news. The ocean near Perth (where I live) was rising at the terrifying rate of 9-10mm per year since 1993, which was, shockingly, “three times the global average”. (Since Perth is flatter than flat, at this rate, in a few years everything bar Kings Park and a few sky-scrapers would be washed away). The myth started because a government department that knows a lot about our roads, trains, and buses wrote a dot point in a Fact Sheet. That was the State of Australian Cities report, and a pollie (Albanese) raved. Then the West Australian newspaper headlined it, and it all got out of hand.

In contrast, Chris Gillham got the raw data (something you’d think The Department of Infrastructure might have thought of), and shows below why its nonsense on stilts.  The rate is not measured from when records began, but from 1993, which (surely it’s just a coincidence) also happens to be the lowest level in local tide gauges since 1941. (See that second last “dip” near the right-end in the graph below?) If they’d started the “rate” from the year 1999, the headlines [...]

Australian temperature records shoddy, inaccurate, unreliable. Surprise!

The BOM say their temperature records are high quality. An independent audit team has just produced a report showing that as many as 85 -95% of all Australian sites in the pre-Celsius era (before 1972) did not comply with the BOM’s own stipulations. The audit shows 20-30% of all the measurements back then were rounded or possibly truncated. Even modern electronic equipment was at times, so faulty and unmonitored that one station rounded all the readings for nearly 10 years! These sloppy errors may have created an artificial warming trend. The BOM are issuing pronouncements of trends to two decimal places like this one  in the BOM’s Annual Climate Summary 2011 of “0.52 °C above average”  yet relying on patchy data that did not meet its own compliance standards around half the time.  It’s doubtful they can justify one decimal place, let alone two?

We need a professional audit.


A team of independent engineers, scientists, statisticians and data analysts (brought together by the joannenova blog) has been going through the Australia Bureau of Meteorology records (BOM). They’ve audited some 8.5 million daily observations across 237 High Quality and other close sites in Australia. Shockingly, while [...]

Announcing a formal request for the Auditor General to audit the Australian BOM

A team of skeptical scientists, citizens, and an Australian Senator have lodged a formal request with the Australian National Audit Office (ANAO) to have the BOM and CSIRO audited.

The BOM claim their adjustments are “neutral” yet Ken Stewart showed that the trend in the raw figures for our whole continent has been adjusted up by 40%. The stakes are high. Australians could have to pay something in the order of $870 million dollars thanks to the Kyoto protocol, and the first four years of the Emissions Trading Scheme was expected to cost Australian industry (and hence Australian shareholders and consumers) nearly $50 billion dollars.

Given the stakes, the Australian people deserve to know they are getting transparent, high quality data from the Bureau of Meteorology (BOM). The small cost of the audit is nothing in comparison with the money at stake for all Australians. We need the full explanations of why individual stations have been adjusted repeatedly and non-randomly, and why adjustments were made decades after the measurements were taken. We need an audit of surface stations. (Are Australian stations as badly manipulated and poorly sited as the US stations? Who knows?)

BOM, GISS have record setting bugs affecting a million square miles?

How bad are these datasets? How sloppy are the data records?

Western Australia (WA) covers 2.5 million square kilometers (1 million square miles, about a third as big as the USA). The average of all WA stations over one month last year was adjusted up by as much as a gobsmacking 0.5 degrees due to a database “bug” – which contributed to August 2009 being the hottest August on record?! That’s one heck of a bug!

Could it get worse? Unbelievably, GISS seems to have lost data for key WA locations that an unpaid volunteer found easily in the BoM online records. GISS only has to maintain copies of records for sixteen stations in WA* which have temperatures current to 2010, but in seven of them they are missing data, and it affects the results. Are they random errors? No, shock me, six errors are upwards: in one case making the spring 2009 average temperatures for Kalgoorlie-Boulder 1.1 C degrees warmer!

But with no-one auditing our BoM or NASA’s GISS, and no team jointly receiving raw data or regulating standards in either agency, temperatures recorded in the field could potentially be listed in official records as being quite [...]