ALMOST exactly three years ago Michael Hammer showed that the official temperature rise profile for the 20th century in the United States is largely, if not entirely, an artifact of adjustments applied after the raw data is collected from the weather stations [1]. It was a very neat little analysis, first published at this blog. It was a neat little analysis that was, for the most part, ignored.
Back then, meteorologist Anthony Watts was busy documenting evidence of problems with the official temperature record in the US because of poor placement of weather stations and Ross McKitrick was attempting to calculate just how artificially elevated temperatures might be as a consequence.
Then interestingly, just last month, John Hinderaker cited the original study by Mr Hammer at Powerline [2] and other studies, concluding:
‘These disclosures highlight a key fact with respect to global temperature data: the data sets are utterly lacking in integrity. Global warming alarmists confidently announce that worldwide temperatures have risen by, say .1 degree over a decade. It would be extraordinarily difficult to take measurements at many locations around the globe that would actually demonstrate that proposition. But the real situation is much worse: no one tells you what temperatures were actually measured at the world’s weather stations. Rather, they report claims of global warming based on “adjusted” temperature data–adjusted by alarmists, with the systematic purpose of manufacturing a rising temperature trend. If you subtract the “adjustments,” it may well be that there has been no net warming over the last 100 years at all.’
Ho Hum. But no one was publishing the proof in the technical literature.

Jennifer Marohasy BSc PhD has worked in industry and government. She is currently researching a novel technique for long-range weather forecasting funded by the B. Macfie Family Foundation.