Created by Mann and his colleagues, it supposedly proved that air temperatures had been stable for 900 years until the 20th century, and then suddenly rocketed off the charts (attributing this to human-caused greenhouse gas emissions).
And while surface stations show slight warming for its Western Peninsula, temperatures over most of the continent have been stable or cooling since 1960.
The period of human settlement over the past 10, 000 years is known as the Holocene, during which time temperatures and hence sea levels (the two having a close correspondence) have been remarkable stable.