The relationship between climate change and wars waged between nomadic andfarming groups from the Western Han Dynasty to the Tang Dynasty period

摘要

In ancient China, shifts in regionalproductivity of agriculture and animal husbandry, caused by climate change,either led to wars or peaceful relations between nomadic and farming groups.During the period spanning the Western Han Dynasty to the Tang Dynasty, 367wars were waged between these groups. While 69?% of the wars wereinitiated by nomads, 62.4?% were won by the farming groups. On acentennial timescale, the battlegrounds were mostly in northern areas (at anaverage latitude of 38.92°?N) during warm periods, moving southward(at an average latitude of 34.66°?N) during cold periods. On adecadal timescale, warm climates corresponded to a high incidence of wars (acorrelation coefficient of 0.293). While farming groups were inclined toinitiate wars during dry and cold periods, their chances of achieving victorywere reduced at such times. The main reasons for this are, first, that a warmclimate provided a solid material foundation for nomadic and farming groups,contributing especially to enhanced productivity among the former. However,the overriding desire of nomadic groups to expand essential subsistence meansled to wars. Second, during cold periods, farming groups moved to and settledin the south, while nomadic groups occupied the Central Plain. Thus, thelocations of the battlefields also changed. While other factors alsoinfluenced these wars, climate change served as a backdrop, playing anindirect role in wars between these groups.