"matt_sykes" wrote:

What happened was this, when the fed the 1.2C per
100% into the climate models in the late 90s they
couldn't recreate the previous 30 years unless they
added a big positive feedback which multiplied that
1.2 C up to 4 C.

The feedback they chose was simplistic. Water Vapour.
snippage

It might be worth having a read of Arrhenius's 1896 paper, "On the Influence
of Carbonic Acid in the Air upon the Temperature of the Ground".

http://nsdl.org/sites/classic_articles/Article4.htm

Page 263 shows that even at this time it was already well known that
relative humidity tends to be conserved - i.e. if temperature rises,
absolute humidity also rises, and that of course amplifies the initial
warming because of the rise in the water vapour greenhouse effect. It's a
straightforward principle of physics, not something invented as a 'fudge' as
you seem to be suggesting.