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Sunday, 29 September 2013

32 Year Cooling Period Discovered!

Even after sitting through the Q&A session following the release of the latest report from the Intergovernmental Panel on Climate Change (IPCC), the Mail On Sunday’s resident naysayer David Rose is sticking to his guns: the warming has stopped, there may even be cooling, and they’re all rotten and nasty because they did’t answer his question the way he wanted.
But, as Nobel Laureate Michael Mann has pointed out, the IPCC report is a deeply conservative document, having been thoroughly researched, with any conclusion that cannot be convincingly supported taken out. It has had to be couched in the kind of language which is acceptable to all the Governments involved. And it still concludes, with 95% certainty, that mankind is largely responsible for the warming.

And, as Phil Plait has explained, there is a natural cycling of temperatures which means they rise and fall over time – or, as has been happening recently, they cycle between rising more steeply and then flattening off. He points out that, when temperatures cycle back once more, the rise will resume. This can be seen when examining temperature movements in the recent past.
As seen in the Mail On Sunday (again)

While Rose bangs on yet again about his “pause”, reproducing the graph that claims there has been no warming since 1997 – that’s over a 16 year period – and then asserts that “because 2013 has been relatively cool, it is very likely that by the end of this year, world average temperatures will have crashed below the ‘90 per cent probability’ range projected by the models”, two can play at that game.

And – guess what – I can find a period in the recent past twice the length of Rose’s recent so-called “pause”, and where I can even show that, over that period, the temperature fell. Yes, I give you a 32 year cooling period: this means I can be twice as certain as David Rose that global cooling is taking place (OK, the temperature rose steeply after the period I selected, but you get the picture).
Thanks to Phil Plait

If I choose 1944 as my start year, and 1976 as the end year, I get a massive 0.25 degrees Celsius of cooling! Eat your heart out David Rose! Sadly, though, going back from 1944 to 1909, there is over that period around 0.6 degrees of warming, and after 1976 there is almost 0.75 degrees of warming over the 22 years to 1998. That illustrates the cycling of the temperatures.

And if you’re wondering what happened to Rose’s “16 year hiatus”, that’s the bit at the top right of the graph. You won’t read about this in the Daily Mail or Mail On Sunday, of course, as the titles are fixated on an agenda passed down to staff after Nigel Lawson bought the legendarily foul mouthed Paul Dacre that lunch. But it is, nevertheless, indicative of what is really happening out there.

That real world, folks, is what should concern us, and not the likes of David Rose.

1 comment:

C Limate-Checker said...

Firstly, I would be curious to see the evidence that a temperature gauge from the late 1800s had the same calibrated accuracy as today's devices.

Secondly, what sampling method is used for the Plait graph? Has it remained the same, or arguably compatible with today's breadth of measurements?