Those of you who still believe that the ClimateGate scandal was just a bunch of emails in England should read this article. James Hansen of GISS appears to have systematically adjusted the historical temperature record to remove a cold patch in the '70s in order to exaggerate the rise since. The amount of change of 0.6 degrees is for one decade is close to the measured change for the whole century. This is vividly seen in these three snapshots of his data being modified:
Watch how the cooling trend of the 1960’s to 1970’s is steadily adjusted up so that 0.3 degrees cooler gradually becomes 0.03 warmer (notice the red and blue horizontal lines in the graphs above).
Mathews Graph 1976: 1955 – 1965 was around 0.3C warmer than 1970’s
Hansen/GISS 1980: 1955 – 1965 was around 0.1C warmer than 1970’s
Hansen/GISS 1987: 1955 – 1965 was around 0.05C warmer than 1970’s
Hansen/GISS 2007: 1955 – 1965 was around 0.03C cooler than 1970’s
Here is what we had thought was the historic temperature, back in the mid-1970s before the deception began. Note how much warmer the '30s and '40s looked then, and how in the charts above it shrinks in significance:
The article goes on to explain how weather balloon data created the prior temperature record, and is considered very accurate. It also matches very closely to satellite data, which started in 1979. Significantly, satellite data has diverged from the surface temperature data, showing less warming, pointing to the deception.
The whole AGW edifice is built on surface temperature from three sources: Hansen's GISS, the UK's HadCRUt and the NOAA. The GISS data is now seen to be manipulated; the HadCRUt data is suspect since it is from the main sources of the ClimateGate emails; and NOAA is even warmer than both of them, suggesting manipulation there too.
Much of the rest of climate science is built on data which is now suspect. What is now seen as Garbage In, Garbage Out had been Garbage In, Gospel Out.