I love the interdisciplinary nature of history. It is always great to get another perspective on the past. In this instance, the science of climatology - including analysis of the written sources - is brought to bear on the climate conditions of Europe during the Viking age. Being Human, by Mary & John Gribbin, offers explanations as to why Iceland and Greenland are so named. I shall paraphrase their points below.

Iceland was discovered by the Vikings in the middle of the ninth century. Irish monks had settled there before them, but soon left once the Vikings joined them. The monk Dicuil wrote about his trip to Iceland in 825, and stated that a day's journey north the sea was permanently ice. The Landnam Saga records that a Norse farmer, Floki Vilgerdason, attempted to settle in Iceland in the 860s. However, this was during a mini Ice Age in an otherwise warmish period spanning from the early eighth century until the late eleventh century. Floki lost his cattle, the sea ice advanced and "he called the country Iceland". But then, a change; sea ice around Iceland is not recorded for the next three hundred years! The next wave of settlers arrived in the 870s and firmly established themselves.

About a century later, with warmer weather conditions, the exiled Erik the Red sailed from Iceland and found another land. Erik called this Greenland. There are a few theories why he gave it this name. One story goes that he saw green glinting on the glaciers in the mountains as he approached. Some of the sagas tell us that he was trying to encourage settlers to come, and so gave it the appealing name of Greenland - basically a con trick. But these sagas were written centuries later when conditions were worse than they are today. Erik happened to land there during a particularly warm period, so it may hardly have been an exaggeration to call it Greenland.

"If Greenland and Iceland had been discovered in the same year by the same explorer, then he might quite logically have called Greenland 'Iceland' and Iceland 'Greenland'. One of the islands is indeed covered by ice, and one is more green and fertile than the other. But they got the wrong names, largely because of minor climatic fluctuations: Iceland was settled at the end of a cold spell, and Greenland near the end of a warm spell. That is why Greenland is no longer really green in the agricultural sense."