What is the actual evidence for Global Warming? With all the noise coming out this week in the media, it is interesting to go back to the basics, i.e. to the actual measurements
The Climatic Research Unit at the University of East Anglia (Norwich, UK) has published temperature times series from 1850 to 2006
These are average global temperature “anomalies” (i.e. amounts above or below the 1961-90 average). Of particular interest the HadCRUT3v series, as it is presented as the most accurate. Uncertainties are in the order of +-0.05C (4 times as much in the XIX century)
If you plot those values, it makes for an impressive graph, with the hockey stick shape and all that. However, a better look at the most recent figures reveals:
- Even if it is true that 2006 has been among the warmest years, the maximum happened in 1998. Its temperature hasn’t been even remotely reached since
- Since 2001, values have not varied more than the accuracy of the data. In other words, there hasn’t been much of a change
- If one stops claiming that temperatures have changed when the figures vary less than the accuracy, the resulting graph is much smoother, with a possible asymptote at 0.3C or 0.4C
All in all there is little or no indication that we are experiencing unprecedentedly increasing temperatures. I am aware that 2007 has been forecast as “the warmest ever”, and it will be interesting to find out if the temperature stability of the past six years will be broken either upwards or downwards
And of course the most one can reasonably say is that “it’s too early to tell“. If only Mainstream Climatology would accept such a simple wisdom!!
What about the 2,500 scientists working for the UN at the IPCC? Well, it is not my fault if they have decided to sell their science to politics. If hundreds of bureaucrats can have a saying on the interpretation of Climate Change data, so can anybody else
What about other evidence of Climate Change such as melting glaciers? The basic tenet of the IPCC is that so-called Greenhouse Gases generated by human activity are responsible for increases in temperatures, and these in turn are changing the climate. So it does all depend indeed on temperatures first.
Somebody, someday will realize that Climate is made of more than just Temperature