Sumerian Climate Change

While the rest of the world is worried about melting glaciers in Greenland and the shrinking of the polar icecaps, resulting in the flooding of New York and other low-lying areas, Matt Konfirst, a geologist at the Byrd Polar Research Centre has been concerning himself with the climate change which happened a few years ago.

4,200 years ago, to be precise!

The ancient Sumerians had a flourishing culture in southern Mesopotamia, which began around 3,500 BC (conventional chronology) - though a people identified as the Sumerians were present in the area around 4,500 BC with the Ubaidian and Jamdat Nasr cultures. However around 2270 BC the Sumerians were conquered by the Akkadians and although their language lingered on, rather as Latin continued as the language of learning and culture into quite modern times, the Sumerians themselves disappeared.

Given the vibrant nature of Sumerian culture - they built the world's first wheel and invented the arch, as well as coming up with the ingenious cuneiform system of writing - historians have long wondered how it was that the Akkadians succeeded them so rapidly and so completely. Undoubtedly weak Sumerian kings and extremely competant and aggressive Akkadian ones were a factor, but Konfirst has been wondering whether there was another factor at work - climate.

Scientists investigating various ancient phenomena have found evidence for a two-century long drought that affected the entire Middle East about this time. Water leves in Lake Van, in south-east Turkey, dropped drastically, and there is evidence that both the Red Sea and the Dead Sea had much higher evaporations rates than before and after this drought. Cores taken from marine sediments and dated to this period show an increase in wind-blown dust from the land, presumably deposited in the sea as protective vegetation died off, desertification took place and the wind carried away the topsoil in vast dust storms.

Interestingly, it has long been known that during the later Sumerian period there was a problem with rising levels of salt in the soil. There is little rain in Mesopotamia and, like Egypt, the country depended upon irrigation from the twin rivers, Euphrates and Tigris. When water was plentiful, the salt would be washed out of the soil, but when water was scarce, evaporation through the soil led to a build-up of salt. Wheat was gradually replaced by the more salt-tolerant barley, though eventually even that could not grow in the salty fields.

There is evidence from the human sphere as well, for 74% of Mesopotamian settlement sites were abandoned during this period and it is estimated that the populated area shrank by 93%! This depopulation seriously weakened the Sumerian city states, to the extent that two waves of nomads swept across the land and even Ur was sacked and destroyed.

If Konfirst is correct, then it is likely that the Akkadians prospered, not because they were a stronger or more capable people, but simply because of the accident that in the north, where they lived, the rainfall was greater. Sparse though it may have been, it was sufficient, in conjunction with the rivers, to ensure that the Akkadians flourished while their neighbours to the south weakened and declined.

Exactly what caused the drought is uncertain. The Middle East in general has become drier over the years and the deforestation caused by human activity has almost certainly played a part in this, but whether deforestation was as great and as widespread back in the Third Millennium BC is probably doubtful. On the other hand, the usual culprits - sunspot activity or an outburst of volcanic activity - is not likely as those factors would not last for two centuries.

Whatever the cause, however, Matt Konfirst has no hesitation in drawing lessons for today: we underestimate the effects of climate change at our peril, he told the annual meeting of the American Geophysical Union in December, 2012. Our vaunted civilisation could collapse just as completely as did the Sumerians were we to be faced with a drought that continued for several centuries.


disappeared Of course "disappeared" is a somewhat loaded word! It is highly unlikey that the invadian Akkadians indulged in genocide or even ethnic cleansing. The whole purpose of conquest was to increase tax and tribute income and you don't get much of either from dead people! However Sumerian rulers ceased to exist and as they were the ones who did the writing, it didn't matter how many peasants survived, as far as the archaeological record was concerned, the Sumerians had "disappeared"! Return

© Kendall K. Down 2012