NASA temperature data tampering is not a one time venture. It occurs repeatedly and has completely corrupted the temperature record. In 1981, NASA showed 0.4 C warming from 1880 to 1980

Challenge_chapter2.pdf
By 1997, they had bumped it up to 0.6C warming from 1880 to 1980

1997.Fig1.GIF
And now they show 0.8C warming from 1880 to 1980. They have doubled global warming by tampering with the data set.

Fig.A.gif
The next graph overlays all three at identical scales, and shows how they keep cooling the past, to create the appearance of a steep warming trend – needed to make the fraudulent hockey stick. Note how the data has been altered more than an order of magnitude further than the current top error bars, shown in green. A smoking gun of fraud.

This graph shows the successive stages of data tampering

1981 version digitized from graph at top
1997 version : GLB.Ts.txt
2015 version : Fig.A.txt
NASA scientists have a strong conflict of interest in that they expect to see warming, and they the more alarm they create, the more money they obtain. This is why climate scientists have no business touching the temperature data. They have no training in signal processing and they have shown repeatedly that they will alter data to suit their needs.
If the facts don’t fit the theory, change the facts.
With four parameters I can fit an elephant, and with five I can make him wiggle his trunk.
There’s no sense in being precise when you don’t even know what you’re talking about.