‘Amateurs’ challenging Bureau of Meteorology climate figures

CONCERNS about the accuracy of the Bureau of Meteorology’s historical data are being raised by “poorly informed amateurs”.

CONCERNS about the accuracy of the Bureau of Meteorology’s historical data are being raised by “poorly informed amateurs”, one of Australia’s leading climate ­scientists has said.

David Karoly of Melbourne University’s School of Earth Sciences, said claims BOM had introduced a warming trend by homogenising historical temperature data should be submitted for peer review.

BOM has confirmed analysis that homogenisation had introduced or dramatically increased a warming trend, but said the process used was common internationally. However, concerns about homogenisation have been raised with climate agencies in the US and Europe.

“The ACORN-SAT network of high-quality station data for Australia from the Bureau of Meteorology has been published after peer-review by international experts,” Professor Karoly said.

Jennifer Marohasy, who in The Weekend Australian raised concerns about the quality of the historical BOM data, has been published in the peer-reviewed climate science literature.

Her paper in Advances in ­Atmospheric Sciences and Atmospheric Research included detail of the methodology used to construct the temperature series for locations in Queensland.

“I’ve looked in the peer-­reviewed literature for justification for the methodology that the bureau uses and I can’t find it,’’ she said. “Sure, there are lots of technical reports and reports from committee meetings and audits by committees but there are no peer-reviewed publications that outline and justify the methodology currently used.’’

Dr Marohasy has analysed the raw data from dozens of locations across Australia and matched it against the new data used by BOM showing that temperatures are progressively warming. In many cases, she said, trends had changed from slight cooling to dramatic warming over 100 years.

Professor Karoly said a recent independent analysis by him of the temperature data for southeast Australia from 1860 to 2010 had been published in the Australian Meteorological and Oceanographic Journal after anonymous peer-review.

He said his paper had shown good agreement with the BOM temperatures, after homogenisation. It confirmed that a 1.1C increase in maximum temperature and 0.9C increase in minimum temperature since 1960 were the largest and most significant trends in southeastern Australian temperatures in the past 152 years.

It said “detailed homogenisation” was undertaken using metadata collected from station history files and a two-step process that involved individual station adjustments and comparison with neighbouring reference sites.

“I am aware of some poorly informed amateurs who have made unsupported claims that are not based on modern scientific methods,’’ Professor Karoly said.

“Those claims do not constitute a debate. Those claims should be submitted for publication in scientific journals and peer-reviewed by experts, to assess the validity of their claims.”