In article ,
John Mackenzie writes:
snip
I think what you are saying is
that it only makes sense to show the anomoly as the difference, i.e.
2.75C higher?

Yes, that's right.
--
John Hall
"If a man will begin with certainties, he shall end in doubts;
but if he will be content to begin with doubts,
he shall end in certainties." Francis Bacon (1561-1626)