Collapse_ How Societies Choose to Fail or Succeed - Jared Diamond [120]
The four elements that form Iceland’s environment are volcanic fire, ice, water, and wind. Iceland lies in the North Atlantic Ocean about 600 miles west of Norway, on what is called the Mid-Atlantic Ridge, where the American and Eurasian continental plates spread and where volcanoes periodically rise from the ocean to build up chunks of new land, of which Iceland is the largest. On the average, at least one of Iceland’s many volcanoes undergoes a major eruption every decade or two. Besides the volcanoes themselves, Iceland’s hot springs and geothermal areas are so numerous that much of the country (including the entire capital of Reykjavík) heats its houses not by burning fossil fuels but just by tapping volcanic heat.
The second element in Iceland’s landscape is ice, which forms and remains as ice caps on much of Iceland’s interior plateau because it is at high elevation (up to 6,952 feet high), just below the Arctic Circle, and hence cold. Water falling as rain and snow reaches the ocean in glaciers, in rivers that periodically flood, and in occasional spectacular superfloods when a natural dam of lava or ice across a lake gives way, or when a volcanic eruption under an ice cap suddenly melts a lot of ice. Finally, Iceland is also a very windy place. It is the interaction between these four elements of volcanoes, cold, water, and wind that has made Iceland so susceptible to erosion.
When the first Viking settlers reached Iceland, its volcanoes and hot springs were strange sights, unlike anything known to them in Norway or the British Isles, but otherwise the landscape looked familiar and encouraging. Almost all of the plants and birds belonged to familiar European species. The lowlands were mostly covered by low birch and willow forest that was easily cleared for pastures. In those cleared locations, in natural low-lying treeless areas such as bogs, and at higher elevations above timber-line the settlers found lush pasture grass, herbs, and moss ideal for raising the livestock that they had already been raising in Norway and the British Isles. The soil was fertile, in some places up to 50 feet deep. Despite the high-altitude ice caps and the location near the Arctic Circle, the nearby Gulf Stream made the climate in the lowlands mild enough in some years to grow barley in the south. The lakes, rivers, and surrounding seas teemed with fish and with never-before-hunted and hence unafraid seabirds and ducks, while equally unafraid seals and walruses lived along the coast.
But Iceland’s apparent similarity to southwestern Norway and Britain was deceptive in three crucial respects. First, Iceland’s more northerly location, hundreds of miles north of southwestern Norway’s main farmlands, meant a cooler climate and shorter growing season, making agriculture more marginal. Eventually, as the climate became colder in the late Middle Ages, the settlers gave up on crops to become solely herders. Second, the ash that volcanic eruptions periodically ejected over wide areas poisoned fodder for livestock. Repeatedly throughout Iceland’s history, such eruptions have caused animals and people to starve, the worst such disaster being the 1783 Laki eruption after which about one-fifth of the human population starved to death.
The biggest set of problems that deceived the settlers involved differences between Iceland’s fragile, unfamiliar soils and Norway’s and Britain’s robust, familiar soils. The settlers could not appreciate those differences partly because some of them are subtle and still not well understood