Our Climategate buddies told us that they wanted to get rid of the 1940’s temperature blip, without even knowing why it existed.
And that they did. The graph below shows the progression of data tampering since 1981 of the global surface (land only) temperature record. In 1981, Hansen showed strong global cooling from the 1930’s through the 1970’s. He got rid of most of that cooling by 2001, and now the same interval shows strong warming.
The 2001 and 2014 data sets are located here:
At the time, there was a unanimous consensus that the Earth was cooling, but James Hansen is just plain smarter than the NASA scientists in the 1960s – who were still able to put a man on the moon.