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Just as we begin to see the colossal price we are being asked to pay for measures to combat climate change, ever more of the evidence adduced to support the global warming scare crumbles away.
A key article of faith for the "warmists" is a supposed increase in the incidence of extreme weather events, such as droughts. As Al Gore claimed to a US Senate committee in March, "droughts are becoming longer and more intense".
But US researchers, led by Gemma Narisma, have now shown that, far from becoming more frequent in recent decades, serious droughts have in fact become rarer than they were a century ago.
In a paper (reported on the website CO2Science.org) they identified the 30 most "severe and persistent" drought episodes of the 20th century.
Seven of these occurred before 1920, seven between 1921 and 1940 and eight between 1941 and 1960, dropping to five between 1961 and 1980.
The last two decades of the century, when the world was supposedly hotting up more than ever, saw just three. The worst drought affecting the developed world was the US Dust Bowl disaster of the mid-1930s.
This corresponds with the recently revised figures for US surface temperatures published by Gore's leading scientific ally, James Hansen of Nasa's Goddard Institute for Space Studies (GISS).
Last month, when Steve McIntyre, an expert statistical analyst, spotted a fundamental flaw in the method Hansen had used to calculate his figures, GISS was forced to publish a new graph, showing that the hottest year of the 20th century was not 1998, as generally accepted, but 1934. Of the 10 hottest years since 1880, four were in the 1930s, only three in the past decade.
This in turn followed the latest satellite figures from the US National Oceanographic and Atmospheric Administration showing how global temperatures in recent years have flattened out at about 0.2 degrees below their 1998 level, and that this summer's figures have been lower than they were in 1983, despite a continuing rise in CO2.
It is clear that 2007 is proving quite a turning point in the climate change debate.
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