When future generations try to understand how the world got carried away around the end of the 20th century by the panic over global warming, few things will amaze them more than the part played in stoking up the scare by the fiddling of official temperature data. There was already much evidence of this seven years ago, when I was writing my history of the scare, The Real Global Warming Disaster. But now another damning example has been uncovered by Steven Goddard’s US blog Real Science, showing how shamelessly manipulated has been one of the world’s most influential climate records, the graph of US surface temperature records published by the National Oceanic and Atmospheric Administration (NOAA).

Goddard shows how, in recent years, NOAA’s US Historical Climatology Network (USHCN) has been “adjusting” its record by replacing real temperatures with data “fabricated” by computer models. The effect of this has been to downgrade earlier temperatures and to exaggerate those from recent decades, to give the impression that the Earth has been warming up much more than is justified by the actual data. In several posts headed “Data tampering at USHCN/GISS”, Goddard compares the currently published temperature graphs with those based only on temperatures measured at the time. These show that the US has actually been cooling since the Thirties, the hottest decade on record; whereas the latest graph, nearly half of it based on “fabricated” data, shows it to have been warming at a rate equivalent to more than 3 degrees centigrade per century.

When I first began examining the global-warming scare, I found nothing more puzzling than the way officially approved scientists kept on being shown to have finagled their data, as in that ludicrous “hockey stick” graph, pretending to prove that the world had suddenly become much hotter than at any time in 1,000 years. Any theory needing to rely so consistently on fudging the evidence, I concluded, must be looked on not as science at all, but as simply a rather alarming case study in the aberrations of group psychology.