Why did the Vikings abandon Greenland?

They left because of a lack of economic opportunity and fear over the loss of their cultural identity.  That answer is provided by recent research detailed in this fascinating story over at the German news-site Der Spigel International:  Archeologists Uncover Clues to Why Vikings Abandoned Greenland.  They weren't starving, but were afflicted with other problems caused by their increasing economic & cultural isolation from their homelands, as the article explains:

So, if it wasn't starvation or disease, what triggered the abandonment of the Greenland settlements in the second half of the 15th century? The scientists suspect that a combination of causes made life there unbearable for the Scandinavian immigrants. For instance, there was hardly any demand anymore for walrus tusks and seal skins, the colony's most important export items. What's more, by the mid-14th century, regular ship traffic with Norway and Iceland had ceased.

As a result, Greenland's residents were increasingly isolated from their mother countries. Although they urgently needed building lumber and iron tools, they could now only get their hands on them sporadically. "It became more and more difficult for the Greenlanders to attract merchants from Europe to the island," speculates Jette Arneborg, an archeologist at the National Museum of Denmark, in Copenhagen. "But, without trade, they couldn't survive in the long run."

The settlers were probably also worried about the increasing loss of their Scandinavian identity. They saw themselves as farmers and ranchers rather than fishermen and hunters. Their social status depended on the land and livestock they owned, but it was precisely these things that could no longer help them produce what they needed to survive.

Although the descendants of the Vikings had adjusted to life in the north, there were limits to their assimilation. "They would have had to live more and more like the Inuit, distancing themselves from their cultural roots," says Arneborg. "This growing contradiction between identity and reality was apparently what led to their decline."

Culture and economics count, and what really counts for young people is a sense of opportunity in building a future. If a society can't provide that, its young people will move on. Something for our own society to ponder in light of the increasing lack of opportunity for young people created by the poor economy and the scourge of personal debt created by the higher education bubble.