So what is the reason for this positive addition to the surface temperature record? Well, there is reason to believe it is simply to eliminate the cooling that broadly occurred between 1940 and 1980 when the CO2 concentration in the atmosphere was increasing. This was not good for the claim that man's use of fossil fuels was causing a catastrophic rise in surface temperatures, just as the present failure of the temperature to rise in the last 17 years is also an embarrassment to that hypothesis.
Steven Goddard produces an e-mail from Tom Wigley to Phil Jones that points to a non-scientific reason for the adjustment reminiscent of a high school student fudging results in a laboratory report to get the expected answer from a botched experiment.
So why is this important? For one thing, Tom Wigley was a member of the UCAR team. This outfit describes itself on its website today as:
The University Corporation for Atmospheric Research is a consortium of more than 100 member colleges and universities focused on research and training in the atmospheric and related Earth system sciences. Our members set directions and priorities for the National Center for Atmospheric Research, which UCAR manages with sponsorship by the National Science Foundation. Through our community programs, UCAR provides innovative services in support of the community's education and research goals.Phil Jones was the head of the Climatic Research Unit at the University of East Anglia in the UK, before his shenanigans revealed by ClimateGate cost him his job. Phil Jones was a principal coordinator of the science that was incorporated into the first four IPCC reports backing the theory of catastrophic man-made global warming. So, Tom Wigley of the UCAR climate research coordinating group for all government-funded climate research in the US was scheming with the head of the very important Climatic Research Unit in the UK to fraudulently produce more evidence for their pet theory, as they were being encouraged to do by their governments. UCAR was and is essentially a propaganda unit charged with also keeping government-funded researchers in-line by setting "directions and priorities" in collusion with the National Science Foundation.
There is almost nothing in the government-managed record of temperatures that one can believe in any more. The record is highly fudged and the fudgers have no idea themselves what string of changes they made to the data, whether as to how often, how much, or why. But, those changes appear to systematically be motivated by attempts to prove the hypothesis that man's use of fossil fuels was somehow causing a catastrophic global warming.