Australia's Bureau of Meteorology maintains one of the world's most scrutinised long-term temperature datasets: ACORN-SAT, drawing on 112 weather stations to track warming of more than 1.5°C since 1910. Over the past week, The Australian newspaper launched a multi-piece campaign — at least eight items including stories, editorials and cartoons — claiming a "forensic audit" had exposed "widespread errors" raising questions about the "integrity of records used for climate analysis." Former PM Tony Abbott called for an independent review. News24 and 2GB amplified the claims. The audit was conducted by Tom Berger, described as a former computer engineer who also runs a 30-year corporate entertainment business "mesmerizing corporate audiences" with mind-reading and persuasion tricks, and Geoff Sherrington, a retired geochemist from a mining company who signed a 2022 declaration rejecting CO2's role in climate. The audit report contains no methodology section, stating only that statistical software and computer coding were used. This absence alone would disqualify the work from any peer-reviewed journal or serious technical review. The most prominent finding — duplicate minimum temperature readings for Sydney's Observatory Hill in August 1907 and August 1867 — sounds alarming until you learn that ACORN-SAT does not use data before 1910. The bureau examined the full claims and found fewer than 200 affected observations out of 7 million in the dataset. Four months of duplicate data were confirmed, all from handwritten records manually digitised onto punch cards in the 1950s or 1960s. The resultant impact on Australia's long-term temperature record is, in the bureau's words, "so small as to be statistically irrelevant." Another flagship claim — that 17 consecutive days of 31°C maximums at Palmerville in 2004 was evidence of "data failure" with odds "less likely than winning the lottery every week for a year" — fell apart when the bureau noted the audit had not accounted for the fact that historical observations at that site were recorded to the nearest whole degree. In a tropical location with low daily temperature variability, repeated readings at the same rounded value are entirely expected, not suspicious. The audit's co-author David Evans declared that "secret climate business" at the bureau had to end, demanding the release of raw data — which was already publicly available and was, in fact, the very data the audit itself relied upon. ACORN-SAT has undergone two prior independent reviews, and its methods have been published in peer-reviewed journals. Independent MP Andrew Wilkie, who forwarded the audit to the bureau on Berger's behalf, told the Guardian he was not contacted by The Australian for comment, felt uncomfortable his involvement might be misread, and had "no reason to reconsider my trust in the bureau." The pattern here is not new. Climate sceptics have targeted the bureau's temperature records for over 15 years, and The Australian — not the scientific literature — has consistently been the outlet of choice. Scientists have described previous episodes as "harassment," and a former bureau head called the source of attacks a "fever swamp" that wastes scientists' time. Each campaign forces the bureau to divert resources to rebutting claims that have no methodological foundation, creating a repeating extraction cycle where the cost is borne by public institutions and the benefit accrues to media outlets and political actors who profit from manufactured doubt. Multiple independent datasets confirm Australia's warming trend. The ACORN-SAT record is one of many. The campaign's implicit premise — that discrediting one dataset would undermine the entire case for climate action — is structurally false, but its political utility does not depend on being correct. It depends on being loud enough to shift the conversation from policy to process, from action to audit.
