Societal Collapse: Climate, Environment, and Civilization

Introduction: Environment, Climate, and Societal Collapse

Environmental determinism has long been out of favor among historians and social scientists, although well into the nineteenth century even the majority of Westerners were highly dependent on the climate and environment for their survival. Since the entire world economy was based on agriculture, a shortfall in harvests meant famines, epidemics, and death for those who were at or below subsistence level. Such famines were a primary cause for the overthrow of the monarchy in France in 1789, and they led to rebellions, riots, and instability wherever they occurred. As late as the 1840s in Ireland, the great potato blight led to the death or emigration of half the population and the near-destruction of Irish society.

In the cases of Easter Island, Norse Greenland, and Classic Maya civilization, climate change combined with deforestation and agricultural practices that destroyed the environment led to the total collapse of these societies. These examples should serve as object lessons for the depletion of natural resources and environmental destruction taking place today, when human technology is far more advanced than anyone in the past could have imagined and its impact on the global climate and environment is infinitely greater.

Climate History and the Interglacial Context

Historically speaking, the present industrial civilization is a phenomenon situated in a relatively warm period between ice ages. In the last ice age, atmospheric carbon was at a low of 180 parts per million, which had risen to 260 parts per million by its end.¹ All the early agricultural civilizations in the Nile valley, China, India, and Mesopotamia came into existence after the ice retreated approximately 12,000 years ago, and all depended on irrigation for their survival. Some periods of this interglacial age have been warmer than others, such as the Medieval Warm Period of 900–1200, or the present period of global warming caused by deforestation and the burning of fossil fuels.

In contrast, during the Little Ice Age of 1300–1850, glaciers moved further south than at any point in the previous 12,000 years, and only began to retreat in the nineteenth and twentieth centuries. This climate shift destroyed the Norse colony in Greenland, while "colder and wetter weather and malnutrition from low crop yields made humans more susceptible to diseases from flu to malaria."² Unlike the Norse, however, most Europeans adapted to this colder climate by building stronger vessels capable of sailing far out into the Atlantic during storms, and by developing new, more intensive agricultural techniques in Britain and the Low Countries that "offered effective protection against the famines of earlier times."³

As European farming methods spread throughout the world over the last two hundred years, deforestation contributed to global warming and the increase of carbon in the atmosphere — effects that were unknown when modern industry and agriculture were first developed. As Easter Island, the Greenland Norse, and the Classic Maya also demonstrate, human activities have always affected the climate and environment at least as much as solar activity, volcanic eruptions, and other natural phenomena. Civilizations that fail to understand and adapt to their environments are ultimately doomed to extinction.