And if all others accepted the lie which the Party imposed -if all records told the same tale — then the lie passed into history and became truth. 'Who controls the past,' ran the Party slogan, 'controls the future: who controls the present controls the past.' And yet the past, though of its nature alterable, never had been altered. Whatever was true now was true from everlasting to everlasting. It was quite simple. All that was needed was an unending series of victories over your own memory. 'Reality control', they called it: in Newspeak, 'doublethink'. - George Orwell; Chapter 3, 1984 [source]The following excerpt from Tom Nelson's blog of January 24, 2012:
GISS Make The Past Colder In Reykjavik « NOT A LOT OF PEOPLE KNOW THAT
I have contacted the Iceland Met Office to get their view on the GHCN adjustments. Their reply could not be clearer :-
a) They were not aware these adjustments were being made.
b) They do not know why they have been made, but are asking!
c) They do not accept the “corrections” and have no intention of amending their own records.
It has become commonplace for climate data to be "adjusted" in a way that shows temperatures a century ago to be colder than they were recorded. In this way, a modest 1° reduction at the beginning of the 20th century data becomes a severe global warming of 0.9° by the end of the century.
Just to put some numbers to this, here is a selection : [source]
Year Last Week This Week Diff 1911 5.31 4.21 1.1 1941 5.28 4.09 1.19 1971 5.85 4.65 1.2 1991 6.12 4.92 1.2 2011 5.58 5.58 0
It appears that climate science, as well as economics, has data that can be adjusted and interpreted to fit the story that needs to be told.