Ihave always thought that climate change is a load of twaddle. However, I am not without shame, so I thought I would try to get a grip on how Michael Mann managed to get to his prediction that there was no Little Ice Age or Medieval Warming Period and that global warming was a reality.

I first dragged off to Wikipedia, where it is stated: “The test in science is whether findings can be replicated using different data and methods. Numerous scientific papers, using various statistical methods and combinations of proxy records, produced reconstructions broadly simi- lar to the original 1998 ‘hockey stick’ graph, with variations in how flat the pre-twentieth-century ‘shaft’ appears.

“The 2007 [Intergovernmental Panel on Climate Change] Fourth Assessment Report cited 14 reconstructions, ten of which covered 1 000 years or longer, to support its strengthened conclusion that it was likely that northern hemisphere temperatures during the twentieth century were the highest in at least the past 1 300 years. Eight or more subsequent reconstructions, including one by Michael Mann et al, 2008, have supported these general conclusions.”

Well, that’s pretty much it, then, hey? But I dug a bit deeper and found that this is how Mann did/does his predictions: owing to a lack of thermometers and people with the wit to use them, temperature records are variable before 1800. So they drilled holes into trees to count the spacing between the rings. There is one ring a year. So, selecting a 2 000-year-old tree (there are some), they measured the rings against the average temperatures from 1900 to 2000. They created an equation which related these.

Then they applied the equation to temperatures from 1800 to 1900 to see if the ring spacing and temperatures match up. If they do, they can then use the tree rings going back 2 000 years to predict temperatures. All clear? Well, naturally, you do need a few trees for this. Big ones. I mean, you’re not going to be predicting temperatures in deserts such as the Kalahari, Namib, Sahara, Arabian, Gobi, Gison, Simpson, Atakama or the Kyzyl Kum deserts. So what – if it freezes or fries in a desert, do you care about global warming?

Back to Mann. But hist! Look again at the bit from Wikipedia quoted above: “. . . it was likely that northern hemisphere temperatures during the twentieth century were the highest in at least the past 1 300 years.”

Oh, dear! So it is not ‘global’ at all. Looking deeper, we find that, in all his tree rings and temperatures, Mann has not one tree from Africa.

So, are we exempt from global warming? Is it for a lack of trees? Well, we do have some big trees. The 6 000-year-old Sunland Big Baobab, in Modjadjiskloof, Limpopo province, is famous for being the widest of its species in the world. Plenty of rings there, huh? But hist! (again) . . . when baobabs are 1 000 years old, they begin to hollow inside. So no rings! But (this is South Africa) inside the hollow Big Baobab is something more famous than tree rings – the Baobab Tree Bar . Oh, well.

Naturally, Mann also left out Madagascar (which has some big trees) and skipped all the other Indian Ocean islands. But I don’t get it. All temperature records are kept at places which, to some degree, are civilised and becoming increasingly so. Micro cli- mates develop. Temperatures increase. So the whole picture falls apart.

According to the US National Aero- nautics and Space Administration, last year was the warmest since temperature records began in 1880. Really? Began in 1880 where? Do they mean that US temperature records began only in 1880? I say this because the longest-running temperature record is the Central England temperature data series, which starts in 1659.

And if you look at it, you will see that 2006 (not 2012) was the warmest year on record, but temperatures (in the UK, anyway) are heading back to the 1780-to-2012 average. I don’t know, I really don’t know. Let’s face it: global warming is a good topic. Good for research funding, scaremongering and sensational editorial copy, and for justifying ludi- crous things like wind farms. As science, it is junk. Let us have a drink at the Baobab Bar.