Why Did Greenland’s Vikings Vanish?

Vikings settled in Greenland from 985 CE to somewhere around 1424, then all written records of them vanished. The conventional wisdom is that they flourished in the northern island during the Medieval Warm Period, then could not adapt to the cold after the eruption of the Indonesian volcano Lombok caused global cooling. The changed conditions devastated the Viking's livestock and crops, while the Inuit survived because they lived off seafood. But did those Vikings really die out? Konrad Smiarowski is leading an excavation in Greenland that paints a different picture. 

“Probably about 50 percent of all bones at this site will be seal bones,” Smiarowski says as we stand by the drainage ditch in a light rain. He speaks from experience: Seal bones have been abundant at every site he has studied, and his findings have been pivotal in reassessing how the Norse adapted to life in Greenland. The ubiquity of seal bones is evidence that the Norse began hunting the animals “from the very beginning,” Smiarowski says. “We see harp and hooded seal bones from the earliest layers at all sites.”
A seal-based diet would have been a drastic shift from beef-and-dairy-centric Scandinavian fare. But a study of human skeletal remains from both the Eastern and Western settlements showed that the Vikings quickly adopted a new diet. Over time, the food we eat leaves a chemical stamp on our bones—marine-based diets mark us with different ratios of certain chemical elements than terrestrial foods do. Five years ago, researchers based in Scandinavia and Scotland analyzed the skeletons of 118 individuals from the earliest periods of settlement to the latest. The results perfectly complement Smiarow­ski’s fieldwork: Over time, people ate an increasingly marine diet, he says.

If the Vikings adapted to Greenland's conditions like the Inuit did, why did the Vikings disappear from the historical record? Scientists have differing theories, as laid out in an article at Smithsonian.