In the past 24 hours I have watched two documentaries which had a resonance with the current distress over global warming.

For a start allow me to declare my own position. Yes I accept that CO2 levels are climbing. No I don't see any scientific link between global waring and CO2 levels. Historical warming and cooling trends bare no relationship with historical CO2 trends. On the other hand there is evidence that global climate changes appear to track sunspot activity.

Thus my personal belief is that anxiety about CO2 emissions are a kind of hysterical reaction to a problem which is not proven to exist.

One documentary which got me thinking was about the Mayans who experienced catastrophic droughts around 800 AD. Mayans blamed members of society whom they thought offended the Gods and began waves of human sacrifices to appease the Gods to restore their climate.

Then I saw another documentary about the mini Ice Age of the 14th Century. Again members of society who did not conform were held to have displeased God and brought on climate changes. Across medieval Europe the Inquisition executed 50,000 people held to have caused climate change.

Now people who fly in jets on vacation, or who use plastic shopping bags are being vilified as eco-terrorists. All this is based on nothing more than an unproven theory linking CO2 with climate changes.

We pride ourselves that we are psychologically superior to our forbears but are we ?

Don't we share the same primordial fears as the Mayans and medieval Europeans, but just use more sophisticated arguments to disguise the same old superstitions ?