By the 1930s and 1940s, the Arctic had warmed 10 degrees, the glaciers of Norway and Alaska had lost half their mass, the glaciers of Greenland and Norway were nearing catastrophic collapse, and glaciers were disappearing all over the world. NASA responded by tampering with the thermometer data to make the warmth disappear.
Here is NASA’s response. They simply cooled the past to make the prior warmth disappear.
Read more at Real Climate Science