Louise Gray of the Daily Telegraph, generally highly sympathetic to green causes, reported that Hand had accused Mann of using “inappropriate” methods that had “exaggerated” the threat from climate change . . .

The article continued with harsh words about Mann:

Professor David Hand said that the research – led by US scientist Michael Mann – would have shown less dramatic results if more reliable techniques had been used to analyse the data… But the reviewers found that the scientists could have used better statistical methods in analysing some of their data, although it was unlikely to have made much difference to their results.

That was not the case with some previous climate change reports, where “inappropriate methods” had exaggerated the global warming phenomenon. Prof Hand singled out a 1998 paper by Prof Mann of Pennsylvania State University, a constant target for climate change sceptics, as an example of this. He said the graph, that showed global temperature records going back 1,000 years, was exaggerated – although any reproduction using improved techniques is likely to also show a sharp rise in global warming. He agreed the graph would be more like a field hockey stick than the ice hockey blade it was originally compared to. “The particular technique they used exaggerated the size of the blade at the end of the hockey stick. Had they used an appropriate technique the size of the blade of the hockey stick would have been smaller,” he said. “The change in temperature is not as great over the 20th century compared to the past as suggested by the Mann paper.” . . .

The New Scientist’s report , also by a very green reporter, . . . reported that the “strongest example of imperfect statistics” was said to occur in the work of Michael Mann, which had led to “exaggerated” results:

[Hand] said the strongest example he had found of imperfect statistics in the work of the CRU and collaborators elsewhere was the iconic “hockey stick” graph, produced by Michael Mann of Pennsylvania State University in University Park. The graph shows how temperatures have changed over the past 1000 years (see graphic, right). Hand pointed out that the statistical tool Mann used to integrate temperature data from a number of difference sources – including tree-ring data and actual thermometer readings – produced an “exaggerated” rise in temperatures over the 20th century, relative to pre-industrial temperatures. That point was initially made by climate sceptic and independent mathematician Stephen McIntyre.