Collapse - Chapter 6

The Vikings of Greenland and Iceland are the subject of the next (and largest) case study. Like the Polynesian expansion, the Viking expansion across Europe and Greenland/Iceland presents many natural experiments with different outcomes from which to draw conclusions.

The Vikings originated from Scandinavia, which after absorbing technological advances from Europe (the plow and sailing) experienced a population explosion that allowed for increased trading and raiding of European settlements. This raiding and increased travel proved to be an autocatalytic process (Diamond's words) that triggered more expansion. Eventually, some travelers settled in remote islands (Shetland, Faeroe and Orkney) and spread to Greenland and Iceland (the pressures to expand were 'pushes' like overpopulation and the 'pulls' of areas with great resources). While these early settlers tried to preserve much of their homeland culture (tree-intensive iron), adaptation can be seen (the switch from cows and pigs to sheep and goats and the adoption of Christianity, for example).

The Viking expansion provides historians with six natural experiments, with 4 variables: distance from maintains (Norway/Britain), resistance from inhabitants, climate (for agriculture) and environmental fragility (soil erosion/deforestation). The first three cases (Orkney, Shetland and Faeroe) still persist today and their success can be attributed to their relative proximity to each and the mainlands. Faeroe, the most northern, could not support as much agriculture, but its proximity allowed for import of essentials (like wood for construction).

The Iceland case study is pretty unique. From the 4 variable, two were favorable: there were no opposing inhabitants to resist settlement, and while Iceland is farther away from the mainland than the previous three islands, it is still close enough to permit bulk trade. Unfortunately, its climate allows for a very short growing season and its soil of volcanic ash is easily eroded and takes time to develop. Thus, while the area seemed lush at first, soil erosion and deforestation started to become a problem very suddenly. In sharp contrast to all the previous examples of the book, the culture of Iceland actually adapted to these alarming changes. Even initially, group decision making could be seen to reduce sheep grazing to prevent soil erosion. This has been instilled into the culture, and now the Icelandic government is one of the most environmentally conservative.

The last case study before moving on to the big one in the Viking expansion (2 chapters worth of Greenland) is Vinland. Briefly, while Vinland (Newfoundland) was ideal for agriculture and environmentally durable, Vikings abandoned settlements because of the extreme isolation from the mainland (and two a lesser extent even neighboring Greenland) and the strength of the current inhabitants, the Native Americans.