It was another bad week for the "warmists", now more desperate than ever to whip up alarm over an overheating planet. It began last weekend with the BBC leading its bulletins on the news that a "leading climate scientist" in America, Professor Chris Field, had warned that "the severity of global warming over the next century will be much worse than previously believed". Future temperatures "will be beyond anything predicted", he told a Chicago conference. The Intergovernmental Panel on Climate Change (IPCC) had "seriously underestimated the size of the problem".
The puzzle as to why the BBC should make this the main news of the day only deepened when it emerged that Prof Field was not a climate scientist at all but an evolutionary biologist. To promote its cause the BBC website even posted a video explaining how warming would be made worse by "negative feedback". This scientific howler provoked much amusement and derision on expert US blogs, such as Anthony Watts's Watts Up With That – since "negative feedback" would lower temperatures rather than raise them. The BBC soon pulled its video.
This was followed on Sunday by yet another outburst from the most extreme of all the scientists crying wolf on global warming, Al Gore's ally Dr James Hansen, director of the Goddard Institute for Space Studies. In The Observer he launched his most vitriolic call yet for the closing down of the coal-fired power stations which are the world's main source of electricity, repeating his claim to a British court last year that the new coal-fired plant at Kingsnorth will alone be responsible for "the extermination of 400 species".
"Coal-fired power plants are factories of death," wrote Hansen, "the trains carrying coal to power plants are death trains". This deliberate echo of the trains carrying Jews to Nazi death camps recalled how the more extreme warmists like to equate sceptics on climate change with "Holocaust deniers". But such overheated language seemed somehow at home in the newspaper which in 1996 solemnly predicted that by 2016 half a million Britons would be dying each year from having eaten BSE-infected beef.
Later in the week sceptics were struck by an admission from Professor William Schlesinger, a lead author for the IPCC. Since one of the enduring myths of our time is that the case for global warming is supported by "the world's top 2,500 climate scientists" on the IPCC, Schlesinger was asked in a public debate how many of its contributors are in fact climate experts. The best he could come up with was that "something on the order of 20 per cent have had some dealing with climate". (This will not of course stop the BBC calling any old evolutionary biologist or economist who supports its views a "leading climate scientist").
Finally there was the strange case of the vanishing Arctic ice. Just how far Arctic sea-ice is melting or growing is one of the issues which arouses most passionate interest in the global-warming debate. Observers were therefore startled last week to see the US National Snow and Ice Data Center (NSIDC) showing a very dramatic drop in sea-ice cover, 500,000 square kilometres of ice suddenly disappearing in the depths of the Arctic winter.
When this was queried by a puzzled Anthony Watts, the NSIDC somewhat shamefacedly admitted that a problem had developed with one of its satellites. The data for the previous 45 days was found to be so faulty that it had been withdrawn. But inevitably this provoked the question as to why quality control seemed to be so poor on one of the world's leading official sources of climate data that it had taken an outside observer to point out that something was wrong,
This is by no means the first time that data on which the official case for global warming rests have had to be corrected, some of the more notorious instances involving temperature data supplied by Dr Hansen's GISS. Yet this is one of the four official sources of temperature data on which the IPCC itself relies. When politicians plan measures to "combat climate change" costing tens of trillions of dollars, we can at least expect them to ensure that their figures are halfway believable.