Sea level rise slowed the advancement of civilization

An abrupt rise in sea level in the northern Aegean Sea likely caused a standstill in the Neolithic Revolution around 7,600 years ago.

At that time, agricultural settlements were just beginning to emerge, signifying the transition from a culture of hunter-gatherers to an agricultural one.

This was a period of major upheaval during the early years of humankind and settlements were just beginning to form spreading out to southeastern Europe and the Mediterranean.  

However, archaeological studies point to a tapering off of these settlements and a subsequent halt in the progress of civilization.

A new study using sediment core samples found evidence of sea level rise that easily explains why progress was ground to a stop.

A team of researchers from the Senckenberg Biodiversity and Climate Research Centre, the Goethe University in Frankfurt and the University of Toronto conducted the research, which was published in the journal Scientific Reports.

“Approximately 7,600 years ago, the sea level must have risen abruptly in the Mediterranean regions bordering Southeastern Europe,” said Jens Herrle, the lead author of the study. “The northern Aegean, the Marmara Sea, and the Black Sea recorded an increase of more than one meter. This led to the flooding of low-lying coastal areas that would have been ideal areas for settlement.”

The researchers focused on tiny fossils of calcifying marine algae found in seafloor sediment in the Aegean Sea.

The researchers used the algae to reconstruct salinity levels in the Mediterranean between 11,000 and 5,000 years ago.

Some of the algae showed drastic changes in ocean salinity during their lifetime which, according to the researchers, could only be explained by a change in sea level.

“These calcifying algae evidence two rapid decreases in the salt content, at approximately 8,400 and again 7,600 years ago, which can only be explained by the fact that a higher volume of low-saline surface water flowed from the Black Sea into the northern Aegean at these times,” said Herrle.

After analyzing the new evidence, the researchers are confident that an abrupt rise in sea level affected settlements along the Mediterranean which explains the halt in progress in the Neolithic age.

What’s more, the researchers say the study could be used as a model to predict the impact that future sea level rise will have on coastal cities.

“Due to climate change, we expect global sea levels to rise by up to one meter over the next 100 years,” said Herrle. “Millions of people could thus be displaced from coastal regions, with severe social and economic consequences.”

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By Kay Vandette, Earth.com Staff Writer