Beginning in the 11th century and continuing for almost 300 years, Greenland and eastern Canada were colonized by Vikings, Basques and other Europeans. In Greenland, the climate was so temperate that row crops and cereals were cultivated and livestock were raised.
There were very few coal plants and even fewer SUV's in the 11th century. Cholofluorocarbons in spray cans were completely unknown. Global warming is cyclic and unrelated to man's puny activities.
Bump.