Congratulations to The Australian again for taking the hard road and reporting controversial, hot, documented problems, that few in the Australian media dare to investigate.

How accurate are our national climate datasets when some adjustments turn entire long stable records from cooling trends to warming ones (or visa versa)? Do the headlines of “hottest ever record” (reported to a tenth of a degree) mean much if thermometer data sometimes needs to be dramatically changed 60 years after being recorded?

One of the most extreme examples is a thermometer station in Amberley, Queensland where a cooling trend in minima of 1C per century has been homogenized and become a warming trend of 2.5C per century. This is a station at an airforce base that has no recorded move since 1941, nor had a change in instrumentation. It is a well-maintained site near a perimeter fence, yet the homogenisation process produces a remarkable transformation of the original records, and rather begs the question of how accurately we know Australian trends at all when the thermometers are seemingly so bad at recording the real temperature of an area. Ken Stewart was the first to notice this anomaly and many others when he compared […]