As of 1999, NASA showed no net warming from 1866 to 1976, with 1877 as the hottest year.
This didn’t suit NASA’s political agenda, so they eliminated all of the pre-1880 years and created a fake hockey stick.
The next graph is an overlay of the two, showing how Gavin perverted the temperature record by tampering and elimination of inconvenient data.
But it gets worse. Gavin not only cooled the pre-1976 years, but he also warmed the post-1976 years. The total tampering from 1880 to 1976 was about 0.45C.
The surface temperature record is completely fake. It is politically driven junk science.