Features Australia

Marble Bar loses on a count back

Homogenising data now alters long-held heat records

21 March 2020

9:00 AM

21 March 2020

9:00 AM

Last year, the cricket world went into a state of shock when the international 50-over World Cup was decided by an esoteric boundary count back rule. Despite the collective disbelief, the rule was known and the outcome accepted by the England and New Zealand teams. The disappointed Black Caps knew their loss was an unchallengeable fact for all eternity.

But, there was less shock and disbelief when, earlier this year, Australia’s Bureau of Meteorology conducted a count back and robbed Marble Bar of the world record for the longest sequence of days above 37.8 degrees celsius, a distinction America’s Death Valley had been denied for 96 long years. Perhaps the response to the BoM’s actions was muted because the climate world has become accustomed to the Bureau adjusting, homogenising and re-shaping Australia’s temperature records to fit its warming doctrine.

Unlike the world of cricket where rules and procedures are transparent for all, the Bureau operates in secret. We’re told it relies on a ‘supervised process’ of ‘expert judgment’ and ‘operator intervention’. Those impertinent enough to question this captain of the universe are judged by the BoM’s supervisor of climate analysis as ‘rather scientifically incompetent… We have a policy of providing any complainer with every single station observation when they question our data (this usually snows them)’. As a senior official, this supervisor presumably reflects his organisation’s elitist disdain for transparency. One former chief executive confirms this, saying ‘people… running interference on the national weather agency are unproductive and it’s actually dangerous.’

While cricket enjoys sunlight, the Bureau of Meteorology prefers a murky, ‘need to know’ world, ensuring no replication of its ‘adjusted’ dataset is possible. It is politically protected and uses every avenue and connection to silence critics – strange behaviour for a publicly-owned weather bureau wanting to be trusted.

Given the BoM’s now predictable behaviour of cooling the past to steepen a warming trend, Marble Bar was always a nail to be hammered down. Temperatures which, under standard exposure conditions, reached or exceeded the century mark every day from 31 October 1923 to 7 April 1924, was an untidy record, in need of adjustment. So, ‘neighbouring’ cooler sites  hundreds of kilometres to the south and east were introduced and, hey presto, the number of very hot days Marble Bar experienced in the period 1910 to 1964 was reduced by 1187.


The Bureau insists it was ‘correcting discontinuities’, caused by a site relocation in 1944. Yet there is no documentation to validate this assertion. A similar claim was made for Rutherglen where it was alleged the weather station had moved between paddocks. Yet again, there is no evidence of the site ever being moved. But, moved or not, a slight cooling trend of 0.35 degree Celsius per century was turned into a warming trend of 1.73 degree Celsius per century.

To say that the Bureau does not have a warming bias is like saying there is no bias at the ABC. Marble Bar and Rutherglen are not isolated examples. We’ve seen how record low temperatures at Goulburn Airport and Thredbo Top Station were missed due to ‘outages’ in those automatic weather stations. Somehow, the crucial Albany Airport data set which should have recorded the coldest- ever April day last year, was ‘lost’. Darwin has had 1.4 degrees Celsius shaved off its official 1910 record. Towns like Alice Springs and Bourke have had their past cooled, mostly in the first half of the 1900s.

Independent Bureau auditor Ken Stewart, surveyed 666 weather stations across Australia. Of these he found 70 per cent were either ‘not fully compliant’ or, did not comply, with the Bureau’s own guidelines. In some cases, minimums were higher than maximums. Yet, the agency boasts its official homogenised ACORN-SAT data record is ‘world-best-practice’. If so, why was it necessary to rewrite it six years later? After all, upwardly revising Australia’s post-1910 mean temperature by 23 per cent is no minor edit.

But then smaller Stevenson screens have quietly been replacing larger ones in the knowledge that evidence from parallel measurements points to a material upward bias in temperatures. There are also constant allegations that the BoM’s practice of recording one second spikes from electronic thermometers exaggerates high temperatures and is not World Meteorological Organisation compliant. Still, combine this practice with a media hungry for global warming headlines and words like ‘unprecedented’ and ‘temperature’ become automatically linked as we saw during the recent Australian bushfire crisis.

At $1 million a day, the BoM is a large and expensive agency, employing nearly 1,700 people. The importance of its database and the reliability of its forecasts go well beyond its daily bulletins.  Governments and the voting public are influenced by it when considering their response to climate change. Many industries and communities still depend on its forecasts, even though it has repeatedly failed to predict catastrophic weather events like floods and droughts.

Yet, whether deliberate policy, sheer incompetence or a combination of both, the culture behind the ‘supervised process’ and the dependability of the agency’s readings, call into question the scientific integrity of Australia’s official temperature records. That said, the Australian Bureau of Meteorology remains the premier weather agency in the southern hemisphere, and its records influence the global dataset.

It would be easy to dismiss debates about the methodology behind Australia’s historical record as a spat between academics and other experts. But there is much more at stake. As George Orwell observed, ‘Who controls the past controls the future: who controls the present controls the past.’ Controlling the Australian climate record and secretly amending it on a ‘trust me’ basis puts the Bureau in an unacceptably unaccountable position. The consequences for public policy are profound.

Marble Bar is just the latest example of record fiddling. If it was cricket, there would be an inquiry into ball tampering.

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