Wrap those guys in a berserker and you got something else again.
The Norse also had a settlement in the North end of Newfoundland at L’Anse Meadows. If you visit there, you will note that they tell you the sea was higher during that warming period. Again,,must have been the impact of the iron forge they had there spitting out CO2.
Vikings don't sound nearly as intimidating when you say it that way.