Vikings left the New World because the walrus market went bust

That is, if we’re counting Greenland as the New World. OK, maybe I’m stretching here – but anyway, AP has new findings that show the Vikings left some of their westernmost settlements not because they got too cold, but because of a boom and bust in the market for precious walrus ivory:

A dozen years ago, many historians believed that the changing climate of medieval Europe was the main reason Norse settlements in Greenland expanded and went extinct. This view was popularized in Jared Diamond’s 2005 book “Collapse.”

But evidence such as walrus bones at archaeological sites in Greenland and historical documents — including church records of tithes paid in walrus tusks — suggested another possible factor: that the Vikings’ descendants thrived on a lucrative trade in walrus tusks, which were sold to Europe’s elite and carved into luxury items, such as ivory crucifixes, knife handles, and fancy dice and chess sets.

James Barrett, another study author and an archaeologist at the University of Cambridge, was “opening dusty boxes and poring through museum catalogues” in galleries in Norway, France, Germany, Ireland, and the UK when he realized that the tusks were often sold attached to fragments of walrus skulls — and that the bone could provide the DNA he needed.

If walrus ivory was the key to Greenland’s medieval wealth, experts now suspect a collapsing market for the ivory may have helped doom the outposts. The Norse Greenland settlements vanished in the 1400s, sometime after life in continental Europe was badly rattled by the onset of the Black Death and the beginning of the Little Ice Age, an era of cooler climates. These calamities undermined demand for walrus ivory, said Barrett.