Climate change: Flexibility allowed societies to benefit

English translation of the APA Science Press release from 13 December 2019:

People were already faced with climate change in the Middle Ages: Between 1200 and 1350 there was "the greatest climatic change in the last 1,000 years before the current warming", according to the Viennese historian Johannes Preiser-Kapeller. He has studied the consequences of this "Little Ice Age" for empires in the eastern Mediterranean and showed that flexibility allowed societies to benefit.

Preiser-Kapeller and his colleague Ekaterini Mitsiou from the Institute for Medieval Research at the Austrian Academy of Sciences (ÖAW) used historical sources and scientific data for their contribution in the anthology "The Crisis of the 14th Century" to reconstruct temperatures and rainfall. They found that the reports of contemporaries and scientific data from the analysis of tree growth rings or dripstones coincide very well. "At that time, average temperatures in some regions cooled by up to 1.5 degrees Celsius, and the frequency of drastic weather events in the reports increased accordingly," Preiser-Kapeller said in a press release.

Climate change affected regions differently: "We see increasingly long and pronounced droughts in the eastern Mediterranean from the middle of the 13th century. In the Nile Valley, too, famines occurred due to precipitation changes occurred in the source area of ​​the Nile in East Africa, leading to too high or too low  Nile floods, " said the historian. Central Asia was also getting wetter and cooler. This allowed the rodents and flees, which transmitted the plague to multiply there. The disease then spread along the trade routes to Europe in the 1340s.

An eruption of the volcano Samalas / Rinjani on the island of Lombok in what is now Indonesia in 1257 AD affected the global climate. This was also noticeable in Europe and offered an "overture" for the more sustainable transition to the "Little Ice Age" in the 13th to 14th centuries (the volcanic eruption shown took place in 1994). © Wikimedia

Effects on different societies are not uniform

The effects on different societies were not uniform. The Ottoman Empire was able to expand from 1350 onwards at the expense of Byzantium. "The Byzantine Empire was an established power and had a correspondingly large apparatus and elites to be cared for. When the plague and the climatic conditions led to a decline in population, these elites continued to try to get the same amount of taxes from a shrinking  population, " said Preiser-Kapeller to APA. This has led to unrest and in part to a greater willingness to join other powers.

"The Ottomans could benefit from this," said the historian. Whole villages changed sides "because the Ottomans had a better offer, with a lower tax burden". This relatively new state structure was not yet so heavily dependent on structures and processes that had been developed over a long period of time and "probably found it easier to adapt to the changes".

But it only took around 250 years for the high point of the "Little Ice Age" to end the boom period of the Ottoman Empire. As Preiser-Kapeller showed in a publication last year, after extreme periods of cold and drought, "the Ottomans hit what had hit the Byzantines before: the Ottoman Empire was an established superpower with an appropriate apparatus and not as flexible as before – they now got into a severe crisis," said the historian.

It is clear to Preiser-Kapeller that long-term crises triggered by climate change are changing societies. "They do it either voluntarily, by adapting, or involuntarily because of social unrest and social upheavals."

In summer 1315 crop failures and famines occurred in large parts of Europe and the Middle East. While western and central Europe were hit by unusual cold and rainfall, many Mediterranean areas suffered from extreme drought ©

Media coverage on the paper Johannes Preiser-Kapeller, Ekaterini Mitsiou (2019). The Little Ice Age and Byzantium within the Eastern Mediterranean, ca. 1200–1350: An Essay on Old Debates and New Scenarios. In Martin Bauch, Gerrit Jasper Schenk (Eds.), The Crisis of the 14th Century: Teleconnections between Environmental and Societal Change? (pp. 190–220). Berlin, Boston: De Gruyter.

Abstract: This paper discusses written historical documentation and paleoenvironmental evidence in order to explore connections between climatic and socio-economic change. It focuses thereby on the Byzantine Empire and the eastern Mediterranean more generally in the period between the collapse and “restoration” of Byzantine rule in Constantinople (1204-1261) and the beginning of Ottoman expansion in the Balkans in 1352, which roughly coincided with the outbreak of the first wave of the “Black Death” in 1347. The paper entails juxtaposing various older scenarios of “fatal” social and political developments in Byzantine history with new studies based on proxy data from regions across the Balkans and Asia Minor and comparing these events with developments in other polities of the region during the transformation from the “Medieval Climate Anomaly” to the “Little Ice Age.”

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