Like many commentators, you frequently use the phrase “Pre-Industrial Temperatures” – most recently in your piece today (Dec 13th) in the Telegraph on Cancun. I should be grateful if you could clarify this term for me.
Do you mean the 17th Century, in the Little Ice Age, when the Thames frequently froze over for extended periods? Or perhaps the Mediaeval Warm Period in the 12th Century, when Greenland was green, and grapes grew in Northern England? The Dark Ages when the chill was comparable to the Little Ice Age? Or the Roman Optimum in the 2nd Century, comparable to the Mediaeval Warm Period?
Perhaps you are thinking of the Holocene Maxima towards the beginning of the current Interglacial, when it was significantly warmer than today for extended periods?
Or are you perhaps going back 20,000 years to the last major glaciation, when the ice sheets covered much of Northern England?
On reflection, would you agree with me that the term “Pre-Industrial Temperatures” is meaningless, and that there is no obvious or natural baseline temperature against which to measure current variation, but rather that climate has always been cyclical and variable? Do you see therefore how it is possible to interpret the slight warming over the last century as an entirely natural and predictable continuation of well-established natural cycles?
As Peter Simple used to say in the Daily Telegraph, “I only ask because I want to know”.
I should be glad of your comments.
ROGER HELMER MEP