Even the church of Global Warming is not without its heretics - those who claim that the iconic "hockey stick" profile of temperature over the past thousand years, which rises inexorably at the end of the millenium, is no more than a craven idol. This is a serious issue since it underpins the Kyoto protocol, which aims to cut emissions of CO2 into the atmosphere by reducing humankind's dependence on fossil fuels. Not all countries have signed-up for it yet - notably the United States whose economy George Bush claims would be destroyed were that nation to implement the Kyoto restrictions. The hockey stick curve formed the central basis of report on climate change by the IPCC (International Panel on Climate Change), upon which the Kyoto protocol is founded. The original hockey stick plot appeared in the prestigious journal "Nature" in a paper by Michael Mann, and referring to the hockey stick figure, the IPCC "Summary for Policymakers" claimed "it is likely that the 1990's has been the warmest decade and 1998 the warmest year of the millenium" for the Northern Hemisphere.
However, Stephen McIntyre and Ros McKitrick have now cast considerable doubt on the validity of the hockey stick fit to the data, and even of the data itself. In a 1995 report from the IPCC, there was no hockey stick. Rather, it showed an interval from ca 1000AD to 1300AD, known as the "Medieval Warm Period", during which many parts of the world were much warmer than they are today. This was followed by the "Little Ice Age" which extended to about 1900AD. It may be concluded thus that current temperatures are nothing special. In a detailed analysis, McIntyre and McKitrick show that an incorrect mathematical procedure was used by Mann, and it also appears that a selective choice and weighting of particular sets of data, based on tree ring measurements, was made.
When the data are re-evaluated, the hockey stick vanishes and the temperatures going back to 1400AD fluctuate around a baseline value, with no rapid rise at the end of the last century. It is further shown that the mathematical procedure used by Mann will generate a hockey stick even when applied to random noise, i.e. data without any trend. The re-analysis does show that the twentieth century was warmer than the previous 400 years, but it was hotter by about 0.2 degrees C from 1400 - 1450AD. Professor Richard Muller at Berkley University is quoted as saying, "[The findings] hit me like a bombshell, and I suspect it is having the same effect on many others. Suddenly the hockey stick, the poster-child of the global warming community, turns out to be an artefact of poor mathematics." This all has profound implications to global policy on climate change.
Dr Hendrik Tennekes, retired director of the Royal Meteorological Institute of the Netherlands has communicated: "The IPCC process is fatally flawed. The behaviour of Michael Mann is a disgrace to the profession... The scientific basis for the Kyoto protocol is grossly inadequate." Nonetheless, consensus of opinion reigns. John Houghton, a British expert who co-chairs the IPCC panel investigating climate change said his work involved between 600 and 700 scientists writing and reviewing about 5,000 papers. "That's a very large body of scientists," he said, and that "worldwide there were no more than 10 scientists active in the field and well-versed in the arguments who disagreed with the notion of human-induced climate change." Clearly, the vast majority of the scientific profession, including Sir David King, the U.K. government's Chief Scientific Advisor, are all singing from the same hymn sheet. Indeed, David King has commented famously that climate change is a greater threat than terrorism.
The mechanism of peer-review will doubtless militate against heretics and dissenters, who would find in the wake of disagreeing with the IPCC a lethal threat both to their funding and to their standing in the scientific community. Even were they to to show sufficient temerity to find evidence against anthropogenic global warming, publication of these results in mainstream journals would prove difficult, as the consolidated establishment would repel their papers.
But what is the truth? If it was warmer at around 1400AD, when a relatively modest population of perhaps half a billion (from the 6.5 billion it stands at today) burnt very little fossil fuels, what is the evidence that current global warming is all our fault? An interesting paper appeared recently in the Journal of Atmospheric and Solar-Terrestrial Physics (Volume 67, 2005, pages 1573 - 1579) which demonstrates a strong correlation between the output of the Sun and global temperatures. The implementation of Kyoto would enforce global economic hardship particularly in developing countries like India and China, while the U.S. will doubtless carry on doing as it likes - business as usual, so long as it can get hold of enough oil, gas and coal. If "Peak Oil" lurks around the corner, as I have written about previously, this might not be possible and there will be conflicts between nations such as China and America for its precious resource. Hockey sticks or otherwise, the world will need to look to Kyoto, or any other means to cut back on consumption, if we are to sustain the global human population at anywhere near our current number.