The National Academy of Sciences just released a new temperature graph (black and brown) which has been massively altered since their 1975 report (red.) Note that they have eliminated most of the 1940-1970 cooling.
Here is why the have to eliminate the the 1940-1970 cooling and the 1940 spike. The next graph appends the post 1970 2014 data to the 1975 data, normalized to 1968. If they didn’t tamper with the data, there is no global warming since 1940.
In 1978, NOAA reported 0.5C global cooling from 1960-1965. NAS has almost completely erased that.
This graph shows the 1978 NOAA data in red, and the 2014 NAS data in black/brown. NAS has warmed 1965-1975 temperatures by about 0.3C.