The Arctic warming from 1910 to 1940 completely wrecks the alarmist’s story. Fortunately for them, they control the NASA and NOAA data and can tamper with it any way they want to produce data which matches their theory.
They are constantly cooling the past in Iceland, with their latest handiwork shown below.
Original version : Data.GISS: GISS Surface Temperature Analysis
Most recent tampering : Data.GISS: GISS Surface Temperature Analysis
What they can’t tamper with is the written record of eyewitnesses.