One of archaeology's 'big questions' is explaining the origins of civilization. In anthropology, 'civilization' has a technical definition. To qualify as a civilization, a society must have all or most of the following characteristics: cities with large populations; a hierarchical social organization, with a king, pharaoh or president at the top of the organizational chart; an economy based on agriculture; monumental architecture; and a system of record-keeping. The earliest civilizations arose in Mesopotamia, Egypt, the Indus Valley and northern China.      
     Various theories have been proposed to explain how this social complexity developed and why it developed in some areas and not others, but archaeologists and historians have not formulated any one satisfying explanation. Nick Brooks, a climate-change researcher at the University of East Anglia in England, offers his idea in the latest issue of Quaternary International. "The emergence of complex societies coincided with or followed a period of increased aridity," which began 8,000 years ago but intensified periodically in subsequent millennia, he said.
     In this view, global climate change caused the profound social changes that have been referred to as the "urban revolution." Brooks states that during large-scale droughts, people would have been forced to concentrate in places where water was available. The social consequences of this aggregation included the formation of managerial elites who controlled the distribution of resources and directed the construction of large monuments to represent and justify their authority. Brooks sees these worldwide social upheavals as ways societies adapted to changing environments.
     Most anthropologists reject such explanations as too simplistic. The environment, they say, cannot alone determine human responses. But when cultures worldwide adopt similar solutions to similar problems, perhaps it’s useful to view civilization as a successful, if not inevitable, response to global environmental changes. The editors of this issue of Quaternary International point out that although "no simple rules seem to govern human (cultural) evolution," it is crucial to try to understand how humans respond to environmental catastrophes.

Source: The Columbus Dispatch (4 July 2006)