By Andrew Alexander 8th July 2009
With Tony Blair launching his own plan to save the world (groans), and the G8 leaders also unveiling their thoughts about global warming, this is a big week for environmental fanaticism.
Whatever he or they offer, it will not be enough to quell the warmists' semi-religious fervour.
They are like medieval preachers, proclaiming to baying crowds that the end of the word is nigh.
Well, is it? There are two separate climate issues - the extent of global warming and the role that humanity plays in it.
Some facts help. The famous 1996 report by the International Panel on Climate Change predicted serious global warming and blamed mankind.
But, since then, the world has disobligingly stopped warming. And two years of global cooling erased nearly 30 years of recorded temperature rises.
What was the worrying rise in temperature - so exciting for those whose computer models used the past to predict a grim future?
Given the margin of error associated with the old-style thermometers which were, until only recently, used to record temperatures, it should be stated thus: over the past 100 years, temperature has risen by 0.7C - plus or minus 1.3 degrees!
The only importance the serious scientists can attach to such a figure is that less serious people think it meaningful.
My own science teacher would have kept me in after school for saying this was a valuable figure.
But, as you will have noticed, it worked. The catastrophists piled in - some of whom had previously flourished warnings about global cooling. For some, any figure will do, especially when it gives them a media profile (and grants for research).
Those who worry about facts should look at the findings of NASA (see the website), whose up-to-date and sophisticated global surveys throw such doubt on the warmists' claims.
They should also read Heaven And Earth by Ian Plimer, Emeritus Professor of Earth Sciences at The University of Melbourne and Professor of Mining Geology at The University of Adelaide.
It is the best book on science and scientists I have ever read. Piece by piece, he takes apart the work of the fanatics. Far from denying global warming, he stresses its regularity and occasional abruptness and how humans have had to adapt.
A millennium ago, Greenland was warm, with a rich agriculture - not much man-made carbon gas then. Over half of the past six million years, the climate was warmer than it is now.
He explains that the supposed consensus view of the IPCC is nonsense. The much-touted 2,500 scientists supposed to have backed its conclusion included many non-scientists or were even the same contributors counted twice.
The finding that human activity influenced global climate involved the deletion of an original passage saying they had no evidence that greenhouse gases played a role and that the best answer was 'we do not know'.
There is always a temptation to assume that anyone labelled a scientist thinks scientifically. Learned philosophers have discussed how experiments are regularly conducted to prove a desired conclusion rather than to ascertain truth.
Prof Plimer provides the sharp-end view of this. The use of computer models excites his particular disdain.
He cites 17 areas of science, ranging from tectonics to meteorology, which need to be utilised in analysing climate change. No computer I have ever heard of can do this meaningfully.
In every area, conclusions, such as they are, are subject to wide margins of error (and often fierce debate).
Simple multiplication demonstrates that even modest margins of error must collectively become magnified into enormous final ones.
As he says: 'If computer models torture the data enough, the data will confess to anything.'
Yet all this leaves a big problem. If the data is really so inconclusive, not to say contradictory, why is the fanatics' message so successful?
This is a profoundly important phenomenon requiring the study of social, political, historical and even religious trends. Catastrophists have, of course, always been with us. There is something in humanity's psyche which delights in impending disaster.
Politicians are attracted because the cause must involve a great increase in the power of government.
The supposed danger has also provided fuel for those who are determined, come what may, to demonstrate that capitalism and industrialisation are the roots of our woe.
The religious instinct is satisfied by the opportunity for pious preaching and noisy protest. Yet the cause is so flawed.
Are we being conned? Yes, why not? Think of all the grand causes in our lifetime which have been bogus, starting with Iraq and Afghanistan and working backwards. Or consider the dishonesty in public affairs, as in MPs' expenses. Fraud is the common coinage of public affairs.
Think, too, that it is little over 200 years since Europe stopped the execution of witches, and less than that since Spain finally abolished the Inquisition. We are, of course, too enlightened now to be in danger of being carried away by superstition or hysteria - so we say.
• Heaven And Earth: Global Warming, The Missing Science, by Ian Plimer (Quartet, £25)