Central England Temperature (part 2)
A sideways look at the longest instrumental record of temperature in the world
In part 1 of this series I took a look at the longest running temperature series in the world, this being the Central England Temperature Record (HADCET), which stretches all the way back to 1659. Subscribers ask if this is one of those ‘adjusted’ temperature series and the answer is most certainly, background for which may be found in this paper by Parker et al 1992.
When it comes to adjusting temperature data the key word to look out for in any methodology is ‘homogenised’. Tony Heller takes viewers through this little trick in this informative 8 min presentation, which reveals how observations from urban areas can bias observations in rural areas. Since thermometers are largely located in urban areas then the global land-based surface temperature record tends to be dominated by the urban heat island effect (UHIE). You’ll find the word homogenised in the first sentence of Parker et al’s 1992 paper, along with mention of an adjustment for UHIE that amounts to 0.1°C. Now that’s darn interesting because we saw an urban effect ten times greater than that up at Wick airport when they replaced the grass airstrip with tarmac and the wooden hut with concrete, brick and corrugated iron buildings just prior to WWII (see this article for details).
Despite the distinct possibility that the Hadley crew haven’t properly adjusted the HADCET series for urban warming I was able to use this series to reveal shenanigans employed in the construction of the CRUTEM5 global anomaly series by the crew at CRU. This crew is the very same climategate mob who were keen on hiding the decline. If you are not familiar with ‘hiding the decline’ or ‘Mike’s nature trick’ then the latest 15min presentation by Tony Heller is a smashing summary. Heller (a nom de plume) was banned from Twitter a while ago, and now that he’s back and firing on all cylinders the trolls have crawled out of the shadows to hound his work and do little more than vomit ad hominem ad nauseam. Follow the puke and you’re more likely to find the truth.
As for those shenanigans we clocked a variation on hiding the decline, this being artificial cooling of the ‘30s and ‘40s that were inconveniently warm for the theory of man-made climate change.
Today’s Dish
And so to dish of the day! Before I put the semi-corrected HADCET time series back in the pantry I had the notion of doing something with carbon dioxide and a few carrots.
The problem with carbon dioxide is that modern day measurements kicked off in the late ‘50s. Before then we have to utilise proxies like ice core samples. Stitching together direct measurements with proxy measurements is a contentious area and may well be a subject that I shall cover in more depth a little later, but for the time being I wanted a cheap solution to the problem and found it in an official CMIP CO2 data record prepared by IAC of Switzerland.
This used to be publicly available and I’m glad I saved a copy of the CSV file before public access to IAC’s servers was removed sometime during 2020. The file is named…
mole_fraction_of_carbon_dioxide_in_air_input4MIPs_GHGConcentrations_CMIP_UoM-CMIP-1-1-0_gr3-GMNHSH_000001-201412.csv
…now that’s a mouthful! This file is a revelation in its own right and I may devote a mini-series to it – please do ask if you’d like a copy.
The data comprise modelled monthly estimates of atmospheric CO2 from the year zero to 2014 to 12 decimal places of precision. Yes you read that right, 12 places of precision. Ludicrous is not the word! It should come as no surprise that the Scripps Mauna Loa global reference series for 1958 – 2022 bolts on to the IAC series for 0 – 2014 like a hand in an expensively tailored glove.
So, then, what we have on my chopping board this fine morning are three prime ingredients: the Central England mean annual temperature for 1659 – 2021, the IAC CMIP mean annual CO2 concentration for 1659 – 2014 and the Scripps Mauna Loa mean annual CO2 concentration for 1958 – 2021. Let’s mash them together and see what we may see!
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