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Central England Temperature - What a waste of time

With all the hoohah over the US surface stations and the apocalyptic warming the Met Office is warning us of I thought it was time for some investigation.

Met Office: HadCET:Central England Temperature
Central England Temperature is representative of a roughly triangular area of the United Kingdom enclosed by Bristol, Lancashire and London. The monthly series begins in 1659, and is the longest available instrumental record of temperature in the world.

The timeseries shows variations across a broad range of timescales, and illustrates recent warming. 2006 was the warmest calendar year in this record by a considerable distance, coming on top of a long run of warm years.

The HadCET data series consist of daily, monthly and seasonal temperatures. Anomalies are also calculated with respect to 1961-1990 climatology. The stations used to compile CET are chosen from the UK surface station network to be consistent as possible with those used historically. The data is then adjusted to ensure consistency with the historical series.

So I have spent several hours looking at the stations, adjustments, aerial photos, musing over the non adjustment for urban warming at Oxford Radcliffe Observatory and then I find that a commenter at Climate Audit has done all the work for me and I had been wasting my time.....

Climate Audit - by Steve McIntyre » Warmest Month
From 1878 to 1930, the monthly CET mean temperature record was the average of “Lancashire” and Oxford, where “Lancashire” was derived from four to seven stations in the northwest of England reduced to a common standard (Manley, 1946)

From 1931 to 1973, the Oxford record was thrown out and replaced by the “corrected” Radcliffe Observatory monthly mean (Knox-Shaw and Balk, 1932).

From 1974 to October 2004, the whole lot was thrown out and replaced by Rothamsted, Malvern, and the average of Squires Gate and Ringway.

And since October 2004, it’s been comprised of Rothamsted, Malvern, and Stonyhurst, equally weighted.

Now, any scientist worth his salt will tell you that while this makes for an interesting record, we cannot draw any kind of firm conclusions regarding the record. In particular, comparing the pre- and post- 1974 records is useless.

Having said all that, here’s the record so you can judge for yourselves whether the current warming is unusual …



Yes, it's a scandal. CET is supposed to be the worlds longest running temperature data but it is more or less useless. In fact it is even worse than you say. Do you know where 'Ringway' is? I didn't so I looked it up. Unbelievably, Ringway is Manchester airport!! Can you think of a more stupid place to put a temperature station?

So trend for the linear fit is 2.5 millikelvin per year, superimposed over a noisy signal with an amplitude of 15 K or so? Anyone who calls that a 'warming signal' should be shot.

Any idea where I can get the dataset? I'd like to play with it. In particular, I'd like to see if the time series is distinguishable from red noise with the same mean and variance.

David, links to raw and sorted data on this post.

As you say, in looking for such small changes in the mean temp in presence of such statistical variance it would be so useful to compare 'like-with-like'.

I wonder if a similar critique could be applied to the UK Rainfall statistics?

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