[Illustrations, full text, footnotes and references available in PDF version]
The truth: The artfully-constructed story in The Guardian carefully failed to put the recent global cooling into perspective. For instance, the paper talks of 2008 as “the tenth-hottest year on record”, but does not tell readers that the record began only in 1880. Nor does it draw attention to the fact that the rise in temperatures during the first 100 years of the instrumental record cannot have had anything much to do with anthropogenic “global warming”, because the population and activities of humankind were insufficient to make an appreciable difference.
The Guardian is careful not to put recent temperature trends into the long-term perspective recommended by Dr. Stott (who was the UK Government’s star witness in its unsuccessful attempt to defend the accuracy of Al Gore’s climate movie: the judge concluded that “the Armageddon scenario that he depicts is not based on any scientific view”. Throughout most of the past half billion years, global temperatures were 7 degrees C (12.5 F) warmer than the present.
It was also warmer than today in each of the past four interglacial periods – the temperature chart in Al Gore’s movie actually shows this, but the audience is carefully misdirected so as not to appreciate its significance. Gore says that whenever CO2 concentration increased the planet warmed, but in fact the reverse was true: whenever the planet warmed, atmospheric CO2 concentrations increased 800-2800 years later (Petit et al., 1999).
For most of the 10,000 years of the present interglacial period, global temperatures were warmer than the present, notably in the Bronze Age climate optimum, when the weather was warmer than today for 2,000 years; and in the Roman and Mediaeval warm periods. Attempts by the UN’s climate panel, the IPCC, to reverse its original finding that the Middle Ages were warmer than now have been thoroughly discredited in the scientific literature: hundreds of peer-reviewed papers by approaching 1,000 scientists demonstrate that the Mediaeval warm period was real; global; and warmer than today.
The Guardian is also careful not to tell its readers that global temperatures have been rising for 300 years since the end of the 70-year Maunder Minimum, during which there were almost no sunspots on the Sun, intense global cooling resulted, and the rivers Thames (in London) and Hudson (in New York) regularly froze over during the winters.
From the end of the Maunder Minimum to the end of the 70-year solar Grand Maximum in 1998, solar activity climbed steadily (Hathaway, 2004), and global temperatures also climbed (Akasofu, 2008). Indeed, the Central England Temperature Record, the world’s oldest instrumental temperature dataset, shows temperatures climbing by 2.2 degrees C (3.5 F) in a third of a century from 1700-1735, a rate of increase at least eight times the mean warming rate of the 20th century.
The Guardian is among many news media that have followed the UN’s climate panel in pretending that the 25 years’ warming that stopped in 1998 occurred at an unprecedented rate. In fact it was identical to the rate observed twice previously in the 20th century. Both the previous periods of rapid warming had occurred before we could have had any real influence on climate.
The Guardian rightly says that the very cold period at the beginning of 2008 was probably caused chiefly by an exceptional La Nina Southern Oscillation – a cyclical change in ocean currents throughout the world that causes a few months’ cooling every three or four years. However, The Guardian was wrong to say the cold weather was not exceptional. Globally, the winter was the coldest in 20 years: in the US and China, the coldest for 50 years.
On one measure (the University of Alabama at Huntsville’s global satellite-temperature dataset), 2008 will be no warmer than 1980, 28 years ago. Why? Because throughout the past seven years, during which The Guardian has been one of the most extreme of the alarmist news media reporting on the imagined “threat” from climate change, all measures show the world has been cooling.
The Guardian is also incorrect to suggest that recent temperature trends are following the path predicted by the UN’s climate panel and the climate models on which it relies. Only one year after the UN published its forecast of how temperatures would inexorably rise as a result of “global warming”, temperatures have in fact plummeted.
Though much of this drop in temperatures will probably soon be reversed following the end of the La Nina event, during 2008 the Pacific Decadal Oscillation, another influential system of ocean currents, switched from its 30-year warming phase to its cooling phase. Also, the Sun has been unusually inactive in the past three years, with more than 400 sunspot-free days. These two circumstances presage at least a slowing in the warming rate so recently but erroneously predicted by the IPCC.
The fall in temperatures for seven years, and the failure of temperatures to show any statistically-significant increase for 13 (or perhaps 28) years, raise serious concern about the reliability of the IPCC’s projections of a rapid warming rate in response to recent increases in carbon dioxide concentration. As matters now stand, global temperatures have not risen above the 300-year warming trend. It is difficult, therefore, to detect an anthropogenic signal in the global temperature record at all.
The IPCC has already had to reduce its projected warming rate compared with the exaggerated forecast it had issued in 1990 (yellow trend-line). However, the outturn (red trend-line) is well below even the revised forecast. And the outturn itself is exaggerated, because the compilers of the global-temperature datasets make inadequate allowance for urbanization and consequent contamination of the temperature trend (McKitrick, 2007: dark red trend-line).
The real-world temperature trend has now been very far below the IPCC’s projections for a long enough period to demonstrate that the official estimates of how much the temperature may increase as a result of CO2 enrichment of the atmosphere must be exaggerations. This is no great surprise: both the 1990 and 1995 reports of the UN’s climate panel had concluded that there was no discernible human influence on global temperature trends, though the 1995 report was rewritten after the scientists had finalized it, so that the published version stated the opposite.
As Glenn Beck wryly commented on his radio show on 6 December 2008 in response to the scare story in The Guardian, “Don’t look at the cooling trend—just remember that the temperatures are going to really heat up in 2015! It’s fun to watch the ‘global warming’ alarmists deflect every little detail that comes out showing global warming isn’t as bad as they say it is—you know, inconvenient small facts like the global temps have cooled in the last decade – not warmed.” End of scare.