Viking Age Iceland: Icelandic climate in the Middle Ages

A picture of Leif Eirksson's statue in Reykjavík, Iceland

This is Part 36 of our ongoing series about Viking Age Iceland. For centuries, this island country, unique in Medieval Europe, operated with no king, no great lords, no foreign policy, and no defense forces but which developed legal and judicial systems to limit the violence of bloodfeud and protect the rights of freemen. Far out in the North Atlantic, Iceland was where the famous sagas developed. To explore Iceland’s place in the medieval world, we present selections from Jesse Byock’s Viking Age Iceland that investigate the history, archaeology, culture, systems of feud, and sagas of this magical place.

Although reliable data for the Icelandic climate in the Middle Ages are scarce, the evidence suggests that from c. 870 to 1170 the climate in the western North Atlantic was unusually mild.[i] During this Little Climatic Optimum, temperatures appear to have been about 1̊ C higher than the more recent average of 4̊ C. The timing of the settlement was thus especially good for a seaborne migration and drift ice, which endangered shipping, was at a minimum. In the mid to later twelfth century, the warm spell that marked the initial phase of settlement ended. A long-term cooling trend began which, among other things, resulted in the more frequent appearance of drift ice along the north-western and north-eastern coasts. The climate did not, however, consistently worsen, and there were intermittent periods of relative warmth. One of these warm spikes occurred at the end of the Free State, lasting from approximately 1200 to 1260, that is during most of what is often referred to as the Age of the Sturlungs.

The onset of centuries-long cooling affected the subsistence economy by limiting the land’s productivity, especially at higher elevations. Predicting fodder yields in a gradually worsening or fluctuating climate must have become more difficult. These changes almost surely increased the sense of competition in an already competitive society oriented to private property. The transformation to a changing climate, sometimes colder and sometimes warmer, may also have contributed to the political turmoil at the end of the Free State in the thirteenth century. From the tenth century on, Iceland suffered periodically from famine and sickness. This island country is a classic example of “bad year economics”, where matters went well only if nothing went wrong.[ii] The short-term variability of the climate played a significant role. In some years, after weeks of especially good weather in the summer and autumn, the rich green valleys and grasslands produced bumper hay crops. Being so close to the Arctic Circle, bad weather had the opposite effect. A series of cold, rainy summers was especially troublesome. Matters worsened when drift ice appeared along the north-western to north-eastern coasts, lowering the air temperature. Such times of small-scale climate fluctuations might cut down the population somewhat, but a buffer period separated the initial bad times from a subsequent population drop.

[i] Páll Bergthórsson 1987; Gerrard 1991; Grove 1988; Grove and Switsur 1994; Lamb 1995; Ogilvie 1984 and 1990.

[ii] Halstead and O’Shea 1989: 1-7.

— Jesse Byock, Viking Age Iceland

Published by Jules William Press

Jules William Press is a small press devoted to publishing the best about the Viking Age, Old Norse, and the Atlantic and Northern European regions. Jules William Press was founded in 2013 to address the needs of modern students, teachers, and self-learners for accessible and affordable Old Norse texts. JWP began by publishing our Viking Language Series, which provides a modern course in Old Norse, with exercises and grammar that anyone can understand. This spirit motivates all of our publications, as we expand our catalogue to include Viking archaeology and history, as well as Scandinavian historical fiction and our Saga Series.