What is known: Vikings sailed to Greenland. They homesteaded there for a few hundred years, and likely experienced multiple famines. Many died. Some returned to European shores. And all of this happened during a time in Europe known to geoscientists as the Medieval Warm Period. The warmer, milder conditions that defined this time eventually ended too.
For many years, scientists have pondered if the Vikings' diaspora to Greenland was made easier by the warmer temperatures of the Medieval Warm Period. Climate data extracted from shells had indicated that this warm period extended to Greenland, but new research looking at glacial movements and using isotope data from terminal moraines suggests this may not necessarily be so.