long summer 2

The backdrop to the next chapter of events discussed in The Long Summer (see Long Summer 1) is the final, cataclysmic implosion of the Laurentide Ice Sheet, around 6200BC. What remained of the shrinking ice sheet was expelled as fresh water in two massive pulses, one towards the Gulf of Mexico and one into the North Atlantic. The effect on civilisations in North America, by then well established, of unprecedented flood waters sweeping across the entire continent must have been catastrophic, yet it is the effects on the communities of Asia Minor which are perhaps more interesting, and certainly better documented archeologically.

Agriculture was de facto across the Eastern Mediterranean by this time. Complex civilisation had began to evolve around the agricultural economy, centred on cities such as Catalhoyuk. When the North Atlantic conveyer once again shut down, cultivation was not something communities could turn to for survival, as during the early days of the Younger Dryas, it was something they had to maintain. Migration, and downsizing, was again part of the immediate response to increasing drought. Many communities settled along the shores of the Euxine Lake, which had formed as great Eurasian rivers such as the Danube and the Dniepr emptied the retreating ice sheets. Here the climate change had created a benign and arable environment, and presumably civilisation briefly flourished, unaware that it was doomed from the beginning. Sea levels from the Laurentide collapse were still rising...

Imagine a lake whose waters suddenly rise 15cm a day. Envisage living in a village on a river terrace a short distance inland, watching an inexorable flood moving upstream as much as 1.6km daily. The inundation never pauses, just rises and rises, drowning crops, leaving only treetops emerging from the still, rising water. A red-brown muck from the water coats the green leaves, which soon vanish beneath the rising deluge. Canoes draw up on the river bank float away. Within days, the flat river valley forms part of a growing, increasingly brackish sea.
All you can do is flee to higher ground. One of the greatest natural disasters to effect humanity came in about 5600BC, when the rising waters of the Mediterranean flooded the deep basin of the Euxine Lake, 150 meters below the Sea of Marmara, to form the Black Sea.
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In two short years, what was once the Euxine Lake was filled t the same level as the inflowing Mediterranean; it was now the Black Sea. The largest freshwater lake in the world had become a brackish ocean, an environmental catastrophe of truly monumental proportions. [Experts] were moved to wonder whether the Euxine cataclysm survived in folk memory to become the biblical Flood, but such attributions are, at best, pure speculation.

Others speculate on the legend of Atlantis. What is certain, is that a huge migration of people was once again put into motion. Some moved south back into Asia Minor and the Levant, settling in lands where agriculture had now existed for thousands of years, eventually founding civilisations such as Babylon, and perhaps putting into writing the events they had experienced; predecessors of the holy scripts. Others moved down the river valleys into lands still covered by primordial forest, populated by hunter gatherer tribes that had descended from Cro-Magnons who had once shared a continent with an entirely different hominid species, the Neanderthals of Europe. Within a few centuries farming communities had spread from the Hungarian Plains to the Low Countries. The major climatic shifts that had affected early human civilisation were largely over. The longest period of suitable, stable climate for 15000 years, the Holocene, had begun, and Europe offered an environment rich in raw materials and ecological diversity. The pulse of colonisation initiated by arguably the greatest social upheaval to befall mankind, set into motion the birth of a network of civilisations that would eventually achieve pioneering levels of cultural development, go on to 'discover' and conquer the rest of the world, industrialise, and gradually impose an economic globalisation that will at the very least set a backdrop for any conceivable future for our species.