Late Antiquity Little Ice Age And Central Eurasian Empires

Of interest-

A 120-year cold spell that spanned the Northern Hemisphere during the 6th and 7th centuries was so profound that it deserves its own name, according to a new study. Analyses of tree rings from more than 150 living trees in the Russian Altai-Sayan Mountains, as well as more than 500 older trees that have fallen to the ground there, provide a complete chronicle of climate stretching from 359 B.C.E. to the year 2011. Of the 20 coldest summers in that region in the last 2000 years, 13 occurred in the 6th century after the year 536, which a recent study of ice cores has pinned down as the date of a massive volcanic eruption somewhere at high latitude in the Northern Hemisphere. Two more large eruptions (in the years 540 and 547) helped render the 540s the coldest decade in more than 2300 years, with an average temperature of about 11.8°C (53.2°F), researchers report today in Nature Geoscience. (For comparison, 2015’s global average temperature was 14.8°C, or 58.6°F.) Particles spewed high into the atmosphere by those eruptions scattered sunlight back into space, thus cooling Earth substantially, the researchers explain. The extraordinary cold spell was probably strengthened and lengthened by the resulting increase in sea ice at high latitudes, as well as an unusually low number of sunspots in the middle of the 7th century. The poor climate may been one of many factors contributing to societal changes of the era, including widespread crop failures and famines in Central Asia that may have triggered migrations from the area to China and Eastern Europe, thus helping spread an episode of plague (depicted in this 15th century painting) that originated there. The researchers’ proposed name for the event is the Late Antique Little Ice Age, a nod to the interval’s falling within the last phases of a period many cultural researchers call the Age of Antiquity.,

Paper: Cooling and societal change during the Late Antique Little Ice Age from 536 to around 660 AD

I am currently reading Empires of the Silk Road: A History of Central Eurasia from the Bronze Age to the Present by Christopher I. Beckwith. It is a rich and dense book on the history of Central  Eurasia,  wherein since the Bronze Age, trade between pastoralists, agriculturalists and cities essentially created and maintained the Silk Road. It was a region typified by an aggressive expansionist mentality in the elites, necessitated in part by a peculiar cultural custom of warriors and their cult, the "Comitatus".  Maintaining these loyal followers was an enormously expensive task, achieved through control over trade routes and often war booty.   In the time period of the cooling in the 6th and 7th centuries there was continued warfare between the eastern Roman Empire and the Persians (6th century) and the expansion of Turkic people westwards from the Altaic region of Siberia. In the early 7th century the disruption of Arab tribal trade and pilgrimage routes by Romans and Persians in northern regions of Arabia saw a rebellion by Mohammed of the Quraysh family who proposed a unification of the tribal peoples of Arabia into one community under one God. And in China, the 6th century saw a reunification under the Sui dynasty after a warring period known as the Sixteen Dynasties and later consolidation under the Tang Dynasty in the 7th century. The Chinese too saw internal rebellion and also warfare with frontier regions which were under the influence of steppe Mongols to the northeast and various Eurasian peoples to the west.

How much of this prolonged warfare (going on for 3 centuries) between the Romans and the Persians and the eventual demise of these two empires in the mid late 7th century, the migration and expansions of Turkic influence in Central Eurasia, the rise of Islam and the disintegration and consolidation of Chinese dynasties be blamed on climate change? I refer to Peter Turchin's meta analysis War and Peace and War: The Rise and Fall of Empires in which he argues that such social and cultural cycles follow their own internal dynamic driven by demographic changes and trends in inequality and social cohesion or "Asabiya" which is society's ability for collective action. Exogenous influences like climate change do matter. But they may simply exacerbate divisions, schisms, and cooperative ventures that were already unfolding for internal reasons. A political ideology to expand and build empires took root early in the history of Central Eurasia, from the Bronze Age horse riding Scythian nomads onward, and has been a recurring theme until recent times argues Christopher Beckwit in his book. Climate change or not, migrations, displacement of people and languages, and the rise and fall of empires has been the inevitable consequence.

Lots to think about and digest from these two books.