Interplay of environmental and socio-political factors in the downfall of the Eastern Turk Empire in 630 CE
Interplay of environmental and socio-political factors in the downfall of the Eastern Turk Empire in 630 CE
复制标题
DOI：
10.1007/s10584-017-2111-0
复制
发表时间：
2017-12-01
期刊：
影响因子：
4.8
通讯作者：
Buntgen, Ulf
中科院分区：
文献类型：
--
作者：
Di Cosmo, Nicola;Oppenheimer, Clive;Buntgen, Ulf
公元 630 年东突厥帝国（ETE，约公元 584-630 年）的崩溃标志着唐朝中国的崛起，成为丝绸之路上的头号强国。随后，唐朝于 659 年击败西突厥帝国，开启了中国向中亚扩张的阶段。中世纪中国的记录中提到，气候引起的环境变化以及经济和政治后果是 ETE 崩溃的主要因素。当前的学术研究也讨论了较低温度的作用。在这里，我们通过根据这一时期的 16 个树轮年表的全球网络评估可用的历史资料来重新评估这个问题，这些年表揭示了公元 626 年至 632 年 ETE 中心地带明显的夏季降温。公元 627 年和 628 年重建的峰值降温高达零下 3.4 A 摄氏度（相对于 1961-90 年平均气候），同时 ETE 地区出现了大雪和严重霜冻事件。格陵兰冰芯中的硫酸盐浓度大约可追溯至公元 626 年，这与表面突然变冷有关。我们认为，气候扰动以及相关的植被生长和牲畜死亡率的减少与理解 ETE 衰落的原因相关，但必须在对突厥和唐领导层内部政治关系的全面分析中评估这些间接驱动因素。我们的研究强调并背景化了过去游牧社会对小规模和偶发性气候波动的脆弱性，特别是在同时发生的社会经济、政治和人口变化的情况下。
The collapse of the Eastern Turk Empire (ETE, ca. 584-630 CE) in 630 CE marked the rise of Tang China as the paramount power on the Silk Road. It was followed by the Tang defeat of the Western Turk Empire in 659 and opened a phase of Chinese expansion into central Asia. Climate-induced environmental changes as well as economic and political consequences are mentioned in medieval Chinese records as major factors in the ETE collapse. The role of cooler temperatures has also been discussed in current scholarship. Here, we re-evaluate this question by assessing the available historical sources in the light of a global network of 16 tree-ring chronologies for this period, which reveal distinct summer cooling in the ETE heartland between 626 and 632 CE. Reconstructed peak cooling of up to - 3.4 A degrees C in 627 and 628 CE (relative to the 1961-90 mean climatology) coincided with heavy snowfall and severe frost events in the territory of the ETE. A strong sulfate spike in Greenland ice cores that has been dated circa 626 CE is implicated in the abrupt surface cooling. We argue that the climatic perturbation and associated reduction in vegetation growth and livestock mortality are relevant in understanding the causes of the fall of the ETE but these indirect drivers must be evaluated within a comprehensive analysis of political relations within both the Turk and the Tang leadership. Our study underscores and contextualizes the vulnerability of past nomadic societies to small and episodic climate fluctuations, particularly when coupled with concurrent socioeconomic, political, and demographic changes.