Checking sources should be as simple as ABC

The Australian Broadcasting Corporation (our ABC) - the main source of news and information for Australia's ruling elite - often begins its broadcasts with the claim its 'free of bias and agenda'. I can't think of a more inappropriate and untrue description. ABC journalists will justify the claim with reference to sourcing information from only the most trustworthy of institutions and experts. The problem of course, is that so many of our institutions have lost-their-way, and so many of our experts take a wholly partisan approach to the most controversial of issues – particularly global warming.

As my colleague Scott Hargreaves explained recently, the average Australian, like the average Brit and American, has mostly lost confidence in experts.

This potentially makes the job of the journalist all the more exciting. Rather than just parroting an authority, they have the opportunity to find out why almost half the population has chosen to disregard expert opinion on a range of issues – including global warming.

Global warming is actually not a hard issue to dissect, because fundamentally it relies on evidence of there being a general trend of temperature increase - and measuring temperatures is not rocket science.

Of course, there is nowhere on Earth where the mean global temperature anomaly can be measured. So, steer-clear when this statistic is mentioned by an expert - you can probably dismiss it as something entirely contrived, like say the Virgin birth.

When I suggest journalists dig-around: I mean for the raw temperature measurements from individual weather stations. Most politics is local, and as you will discover along this journey, the global mean temperature as so often reported by experts is actually a contorted amalgamation of thousands of abused local temperature series - unless the expert is referring to the satellite record, which is another story.

Indeed, while the Australian Bureau of Meteorology often refers to ACORN-SAT… SAT in this context is actually an acronym for 'Surface Air Temperatures'. Not SATellite. (The previous Minister, Greg Hunt, was often muddled on this issue.)

To be clear, the Bureau relies entirely on surface air temperatures for reporting climate variability, and it has very significantly changed the way it measures these temperatures over the last few decades… without showing us that the new method is in any way comparable with the old method.

Meanwhile the Bureau keep claiming new record hot day, which are reported by our ABC without any scepticism.

The change-over from mercury thermometers to electronic probes in automatic weather stations has been occurring for more than two decades, but alarm bells only started ringing for me last year when I discovered that rather than averaging one-second readings from the electronic probes over at least one minute as is standard, the Bureau records the highest one-second reading as the maximum temperature for that day. To be clear: when the Bureau reports, for example that '37.7 degrees Celsius is a new record for Mildura' as they did last September, they are not referring to the daily average, or the temperature after the probe starts beeping to signify it has steadied - they are referring to an instantaneous one-second spot reading.

Because electronic probes are much more sensitive than old-style mercury thermometers to fluctuations in temperature and because temperatures can fluctuate on a hot day by up to 2 degrees Celsius in less than one minute at places like Mildura, this very dubious method of calibration will likely result in new record hot day - even for the same weather.

Since I raised this issue with Minister Josh Frydenberg last year, the Bureau has not denied that they use this non-standard method for recording temperatures, but they claim it results in the same temperatures as would be recorded from a mercury thermometer because they have 'custom-made probes' with a longer than normal time constant.

It would seem reasonable to assume that given the Bureau have been changing-over from mercury thermometers to custom-made probes at its over 600 weather stations for some time now, and because they are relying on a novel method for calibration there would be lots of reports - so many parallel studies - to demonstrate that the new method is above-board. I mean, it would be ridiculous if some of the catastrophic global warming so often reported by experts via our ABC were just a consequence of a new method of recording temperatures!

This should be all very easy to check, except that the Bureau have been far from forthcoming with the relevant data, as I detail in a recent blog post.

And I'm more than happy to make all my correspondence with the Bureau available to ABC journalists should they decide to do some research into this issue - should they choose to convert from true believers to genuine truth seekers… free of bias and agenda.