On the 14th December at 14:50 GG comments:

What is more difficult for me to explain is why before 1900 the trend was opposite. I cannot think of an explanation for it. Anybody has any idea why? I am sure all this stuff must be published somewhere.

It seems to me that this is the issue that really needs to be addressed. Why does Roman’s graph show everything before about 1920-ish go down and everything after go up?

The pattern is not consistent with UHI — it doesn’t seem to fit what you would expect with stations being moved (which should be more random) — I can’t think of a technological reason for thermometers to be registering lower each year since then.

So what is the cause of this pattern of adjustments — how can it be justified from a scientific basis???

What is more difficult for me to explain is why before 1900 the trend was opposite. I cannot think of an explanation for it. Anybody has any idea why? I am sure all this stuff must be published somewhere.

gg – this is what I am really wanting to understand too — and not in the Darwin record (like you I regard one station as a bit of a red-herring) but in Roman’s graph — why does everything before about 1920-ish go down and everything after go up.

Its not consistent with UHI — it doesn’t seem to fit what you would expect with stations being moved (which should be more random) — I can’t think of a technological reason for thermometers to be registering lower each year since then — so what is it.

(Without wanting to get back onto Darwin though — it isn’t a red herring though — all sorts of stations seem to have this pattern of every rising adjustments over recent decades — hence Roman’s graph)