Climate Change and the Rise of the Central Asian Silk Roads

Daniel J Hill

doi:10.1007/978-3-030-00728-7_12

Abstract

The final centuries BCE (Before Common Era) saw the main focus of trade between the Far East and Europe switch from the so called Northern Route across the Asian steppes to the classical silk roads. The cities across central Asia flourished and grew in size and importance. While clearly there were political, economic and cultural drivers for these changes, there may also have been a role for changes in climate in this relatively arid region of Asia. Analysis of a new ensemble of snapshot global climate model simulations, run every 250 years over the last 6000 years, allows us to assess the long term climatological changes seen across the central Asian arid region through which the classical Silk Roads run. While the climate is comparatively stable through the Holocene, the fluctuations seen in these simulations match significant cultural developments in the region. From 1500 BCE the deterioration of climate from a transient precipitation peak, along with technological development and the immigration of Aryan nomads, drove a shift towards urbanization and probably irrigation, culminating in the founding of the major cities of Bukhara and Samarkand around 700–500 BCE. Between 1000 and 250 BCE the modelled precipitation in the central Asian arid region undergoes a transition towards wetter climates. The changes in the Western Disturbances, which is the key weather system for central Asian precipitation, provides 10% more precipitation and the increased hydrological resources may provide the climatological foundation for the golden era of Silk Road trade.

Highlights

The last 6000 years has seen significant climatic and precipitation changes, which have been well documented from both proxy records and modelling studies (Braconnot et al 2004; Harrison et al 2014)
The latest of these occurs at approximately 1500 BCE and its demise may be contemporaneous with climate drying in Mycenaean Greece and Hittite Anatolia associated with the Late Bronze Age Collapse (Kaniewski et al 2013), but quickly returns to typical early Holocene values
The ensemble seems to show a clear transition from the dryer climates of the middle Holocene to wetter climates of the late Holocene between 1000 and 250 BCE (Fig. 12.3)

Summary

Introduction

Climate has changed throughout the course of the human civilization (Mayewski et al 2004). The relationship between these broad-scale, long-term changes in climate and the local environmental impacts is little understood, despite the major disruptions to ancient civilizations across Asia and Africa these have been implicated in (Butzer 2012). Across the world major civilizations have responded to climate change, from Africa (Welc and Marks 2014), Europe (Büntgen et al 2011; Drake 2012), Asia (Staubwasser et al 2003; Dong et al 2012), the New World (Kennett et al 2012) and maybe even the colonization of the Pacific Islands (Anderson et al 2006). As well as driving civilization collapse, climate change could affect societal structures, polities and trade routes, in the Silk Road region, where a complex network of trading routes cross the central Asian dry region

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