It has long been known by scientists that Iceland has gotten much colder since the Medieval Warm period, and that there was a spike in warming from 1900 to 1940, followed by a sharp drop back to the previous low.
As of 2012, NASA showed Iceland temperatures accurately.
This didn’t suit NASA’s global warming agenda, so in 2013 they simply made the 1900 to 1940 warming disappear.
Having been called out on this numerous times, and angering the Icelandic Met Office, NASA has since put some of the spike back.
The warming was very real. In 1939, the glaciers of Greenland and Norway faced “catastrophic collapse.”
The subsequent cooling was also very real. By 1963 the glaciers of Norway were growing for the first time in 200 years.
NASA and NOAA both alter data at will, because their mission under Obama is to push global warming – not tell the truth.