Australian weatherman’s records reveal warming fraud
AS a child, Ian Cole would watch his father Neville take meticulous readings from the Bureau of Meteorology thermometer at the old post office in the western NSW town of Bourke and send the results through by teleprinter.
The temperature was recorded every three hours, including at night when the mercury sometimes plunged to freezing, and the data was logged in handwritten journals that included special notes to help explain the results.
That all changed in 1996 when the Stevenson Screen, the official measuring equipment, was replaced with an automatic station and moved to an airport site.
The Stevenson Screen went to the dump and, but for fate, the handwritten notes could have gone there too. But without instruction, the records were kept and are now under lock and key, held as physical evidence of what the weather was really doing in the mid-20th century.
These Bourke records have assumed a new significance in light of concerns about how historic data is being treated at many sites around the country. The records are also important in an ongoing row that frustrates Mr Cole.
The Bourke cotton farmer may be managing director of the local radio station 2WEB but Mr Cole can only broadcast temperature records that date back to 2000 because the Bureau of Meteorology won’t supply historic records to service provider Weatherzone.
As a result “hottest day on record” doesn’t really mean what it seems. “We keep on being told about records that are not actually records and averages that are not quite right,” Mr Cole said.
Worse still there are concerns about what has happened to the precision of those handwritten records in the earlier years. Bourke now forms part of a network of weather stations used to make up the national record known as ACORN-SAT. The raw temperature records are “homogenised”, a method BOM says has been peer-reviewed as world’s best practice and is used by equivalent meteorological organisations across the world.
Independent research, the results of which have not been disputed by BOM, has shown that, after homogenisation, a 0.53C warming in the minimum temperature trend has been increased to a 1.64C warming trend. A 1.7C cooling trend in the maximum temperature series in the raw data for Bourke has been changed to a slight warming.
BOM has rejected any suggestion that it has tampered inappropriately with the numbers. It says the major adjustment to Bourke temperatures relate to “site moves in 1994, 1999 and 1938 as well as 1950s in homogeneities that were detected by neighbour comparison which, based on station photos before and after, may relate to changes in vegetation around the site”.
Queensland researcher Jennifer Marohasy, who has analysed the Bourke records, says BOM’s analysis is all very well but the largest adjustments, both to maximum temperature series, occurred in the period 1911 and 1915 with a stepdown of about 0.7C, followed by a step-up between 1951 and 1953 of about 0.45C. Of greater concern to Dr Marohasy is that historic high temperatures, such as the record 51.7C recorded on January 3, 1909, were removed from the record on the assumption it was a clerical error. In fact, all the data for Bourke for 40 years before 1910 has been discarded from the official record. If it were there, says Dr Marohasy, the record would show that temperatures were particularly hot during that period.
For Mr Cole it is a simple matter of trusting the care and attention of his father. “Why should you change manually created records?” Mr Cole said. “At the moment they (BOM) are saying we have a warming climate but if the old figures are used we have a cooling climate.”
Posted by John J. Ray (M.A.; Ph.D.).