The algorithms used to create the adjustments are very simple.

1. Pre-1900 temperatures are adjusted upwards to hide the 1900-1940 warming trend, which can’t be explained by CO2
2. The 1930s are adjusted downwards to hide the hottest decade in US history
3. Recent temperatures are adjusted way up, because Hansen’s theory demands that temperatures correlate with rising CO2.

“If the facts don’t fit the theory, change the facts”
– Albert Einstein