You and @NevBhc are both easily fooled and clearly need things spelled out more clearly for you. Some spoon feeding for you given you can't work it out for yourselves >
From https://realclimatescience.com/alterations-to-the-us-temperature-record/#gsc.tab=0
The article details the 1930's temperature before and after temperatures. The change is radical and changes an actual cooling to an altered warming.
The pretty girl goes nowhere near explaining this and no doubt is being used to fool the masses about this by referring to more easily justified alterations on a smaller scale for other reasons. Every con has an element of truth in it to fool low IQ types.
This is just one example."This graph of US temperatures was posted by NASA in 1999, showing a strong cooling trend from the 1930’s through the end of the century. The years 1934 and 1998 are circled."
And this is NASA’s current graph, which now shows a strong warming trend during that period.
They use a pretty presenter for the snow job but leave the above alone entirely.
Wake up to yourselves.
