- Climate change - During the 500-year history of the settlements it is believed that climate change had the most profound and irreversible affect. The Greenland Norse would have seen the winters progressively worsen until shipborne travel became either too dangerous or impossible sometime in the 14th or 15th century.
- Trade with the Scandinavian homelands was vital to the continued success of the settlements. Without it they could not obtain items deemed essential to continue their Norse lifestyle. Walrus and narwhal ivory, walrus hide, and specialty items such as falcons, polar bear cubs, and polar bear hides, were the principal trade goods produced by the settlements. The advent of African and Indian elephant ivory doomed trade in the ivory from the settlements, their most valued commodity.
- The long, dangerous sea voyages from Greenland, to Iceland, and the Scandinavian homeland ended sometime in the 14th or 15th century as the weather in the northern hemisphere steadily worsened with the onset of the Mini-Ice Age.
- The settlers agrarian lifestyles and their failure to abandon European practices of animal husbandry served to drive the last nail in their coffin. The Western Settlement at Lysufjord was abandoned first, sometime in the early years of the 14th century the few holdouts left for good, never to be seen again. About 100-years later the Eastern Settlement at Eiriksfjord was abandoned.
The Mini-Ice Age, about 1300-1800, descended with a vengeance on the northern hemisphere. The extreme winter weather of this period caused human migration throughout the northern hemisphere. The extreme winter weather during the 19th century prompted 1/3 of the population of Sweden to migrate or face starvation.
The same situation faced the remnants of the Greenland Norse settlements in the 13th-15th centuries. They could either wait for the specter of starvation to claim them or they could follow their predecessors to North America. What would you do in their place?