The fact that the weather in northern Europe has turned a bit weird this year has been widely discussed. The coldest March for 50 years - the coldest Easter Sunday EVER... etc. It's easy to forget that last year's March was the exact opposite - just about the warmest ever.
I've always been a bit mixed up regarding climate change. Clearly there has been a big rise in CO2 in the atmosphere due to fossil fuel burning. We know it must happen and we can measure it. We also know from physics that this will cause the Earth to retain more thermal energy and grow hotter. But its very hard to look at global weather and say hmm - that's climate change, because the trend is obscured by the noise (i.e. the random day to day and year to year variations.
But the other day (25th March print edition) the Guardian carried an article about the unseasonal March weather. With it was a graph showing March mean UK temperatures for the last 50 years or so. What was not commented on was the strange behaviour of the graph. In the earlier parts of the time period there seemed to be a rough cycle to the ups and downs, with a few years above average, then a few below - very rough of course. As the years went by the cycle seemed to accelerate, then around 10-15 years ago it seemed to hit an annual cycle - one hot year, followed by one cold. The oscillations grew year on year until the last two years when bang! one extremely hot year, followed by the coldest on record.
Some years ago I read Malcolm Gladwell's "Tipping Point" - a mildly scientific look at "state changes", where complex systems suddenly reach a point where they flip into a new state. Tipping Point was interesting but not super-scientific. Shortly after I picked up Critical Mass: How one thing leads to another - by Philip Ball. This is a brilliant book, covering some good science, reviewing much the same topic. One thing that it discussed was how before a complex system crashes, or changes state, you sometimes see a tell-tale oscillation, just before the flip. It's been detected in stock markets according to some authors.
So - I look at this data - and it just screamed "tipping point". The oscillation and its change over time just looked so pronounced and unusual. But what's the cause of this oscillation? Is it the gulf stream - or some interaction of ocean currents and atmospheric temperatures? That seems likely, although of course there could be other explanations. But what I do think is that a really big paradigm-changing flip may be coming. The really tantalizing question is, is it an up-flip or a down-flip? The data itself gives no real clue - cold or hot - its very hard to be sure which way the flip will go...
