Climate scientists first laughed at a ‘bizarre’ campaign against the BoM - then came the harassment

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.