Mesopotamia: cradle of civilization, the fertile breadbasket of western Asia, a little slice of paradise between the Tigris and Euphrates rivers. Today the swath of land north of the Persian Gulf is still prime real estate. But several millennia ago Mesopotamia was absolutely The Place to Be. There the visionary king Hammurabi ruled, and Babylon’s hanging gardens hung. There the written word, metalworking, and bureaucracy were born. From the stately, rational organization of Mesopotamia’s urban centers, humanity began its inexorable march toward strip malls and shrink-wrap and video poker bars and standing in line at the dmv. What’s more, the emergence of the city-state meant that we no longer had to bow to the whims of nature. We rose above our abject dependence on weather, tide, and tilth; we were safe in the arms of empire. Isn’t that what being civilized is all about?
Not if you ask Harvey Weiss. Weiss, professor of Near Eastern archeology at Yale, has challenged one of the cherished notions of his profession: that early civilizations—with their monuments and their grain reserves, their texts and their taxes—were somehow immune to natural disaster. He says he’s found evidence of such disaster on a scale so grand it spelled calamity for half a dozen Bronze Age cultures from the Mediterranean to the Indus Valley—including the vaunted vale of Mesopotamia. Historians have long favored political and social explanations for these collapses: disruptions in trade routes, incompetent administrators, barbarian invasions. Prehistoric societies, simple agriculturists—they can be blown out by natural forces, says Weiss. But the early civilizations of the Old World? It’s not supposed to happen.
Yet happen it did, says Weiss, and unlike his predecessors, he’s got some data to back him up. The evidence comes from a merger of his own archeological expertise with the field of paleoclimatology, the study of climates past. His first case study concerns a series of events that occurred more than 4,000 years ago in a region of northern Mesopotamia called the Habur Plains. There, in the northeast corner of what is present-day Syria, a network of urban centers arose in the middle of the third millennium b.c. Sustained by highly productive organized agriculture, the cities thrived. Then, around 2200 b.c., the region’s new urbanites abruptly left their homes and fled south, abandoning the cities for centuries to come.
Weiss believes that the inhabitants fled an onslaught of wind and dust kicked up by a drought that lasted 300 years. He also believes the drought crippled the empire downriver, which had come to count on the agricultural proceeds of the northern plains. Moreover, he contends, the long dry spell wasn’t just a local event; it was caused by a rapid, region-wide climate change whose effects were felt by budding civilizations as far west as the Aegean Sea and the Nile and as far east as the Indus Valley. While the Mesopotamians were struggling with their own drought-induced problems, he points out, neighboring societies were collapsing as well: the Old Kingdom in Egypt, early Bronze Age cities in Palestine, and the early Minoan civilization of Crete. And in the Indus Valley, refugees fleeing drought may have overwhelmed the cities of Mohenjo-Daro and Harappa. The troubles of half a dozen Bronze Age societies, says Weiss, can be blamed on a single event—and a natural disaster at that.
