For more than a decade, climate science deniers, rightwing politicians and sections of the Murdoch media have waged a campaign to undermine the legitimacy of the Bureau of Meteorology’s temperature records.

Those records say Australia has warmed by 1.4C since 1910, the year when the bureau’s main quality-controlled climate dataset starts.

Extremely hot days come along more often than they used to, and the warming trends are happening everywhere, at all times of the year.

As a target for those with an often visceral distrust of the established science of human-caused global heating, the bureau’s temperature record might be seen as ground zero.

“This has frankly been a concerted campaign,” says climate scientist Dr Ailie Gallant, of Monash University. “But this is not about genuine scepticism. It is harassment and blatant misinformation that has been perpetuated.”

Despite multiple reviews, reports, advisory panels and peer-reviewed studies rejecting claims that its temperature record was biased or flawed, Gallant says the “harassment” of the bureau has continued.

In the latest challenge, the Australian newspaper – which over the years has elevated claims from sceptics and bloggers on to its pages – is calling for a “proper, expert appraisal” of temperature records after running claims that mercury thermometers occasionally used by the bureau were recording lower temperatures at one location than newer automatic probes in the same place.

One former executive, who for eight years was responsible for the bureau’s main climate record, says the constant criticism has affected the health of scientists over many years, who were diverted from real research to repeatedly answer the same questions.

One of the earliest formal attacks came in 2010, when the then Liberal senator Cory Bernardi joined sceptics to demand the National Audit Office investigate the internationally-recognised technique known as homogenisation, which aims to remove artificial changes in temperature readings such as if a weather station is moved or buildings are erected that could alter readings.


A small band of sceptics have long claimed a conspiracy, without evidence, that the bureau deliberately used homogenisation in its centrepiece dataset of 112 weather stations – known as the Australian Climate Observations Reference Network – Surface Air Temperature (Acorn-Sat) – to make the heating of the continent’s climate appear worse.

Every minute the BoM spends on this nonsense is a minute lost to managing risk and protecting the community
Former bureau boss Rob Vertessy
That effort to engage the audit office failed, but the bureau established its own review with a panel of independent international experts.

That panel reported that “as the world’s first national-scale homogenised data set of daily temperatures” it had “a high level of confidence in the national temperature trends” from Acorn-Sat.

Another independent expert panel reported for three years from 2015 and again backed the bureau’s methods, despite “unsolicited submissions” which they said “do not provide evidence or offer a justification for contesting the overall need for homogenisation and the scientific integrity of the bureau’s climate records.”