At present, some experts believe that the disappearance of Vikings from Greenland has a lot to do with climate change. The first Vikings to land on Greenland were during the mild medieval period, and although the island had few resources, it was enough to support thousands of Vikings. At the beginning of the 15th century, the world entered the Little Ice Age, and the extreme cold made life difficult for the Vikings on the island.
Snow covered the grass and the Vikings were unable to continue their livestock and had to rely on fishing for a living. The Vikings were a seafaring people, but not a fishing and hunting people.
What's more, snow and ice covered the forest, and the Vikings were unable to log, transport trees, build ships, or continue their once-proud sailing careers. The Little Ice Age also filled Greenland with ice sheets, halting trade entirely by European merchant ships. This made the Vikings even worse.
Due to prolonged cold, food shortages and malnutrition, more and more Vikings died.