In 1998, Hansen wrote :
it is clear that 1998 did not match the record warmth of 1934, which occurred during the Dust Bowl era
NASA GISS: Global Temperature Trends (This document was deleted from NASA servers in 2004 or 2005)
His 1998 graph showed 1998 as being the third warmest year – after 1934 and 1921, with 1998 a full degree cooler than 1934. It also showed a strong cooling trend after the 1930s.
Two years later he simply altered the data to make 1998 warmer than 1934 and 1921.
The animation below shows how he magically altered the data to match the theory.
h/t to Dave Burton