西汉至五代中国盛世及朝代更替的气候变化和农业丰歉背景

The climatic and harvest backgrounds of dynastic flourishing ages and transitions in China during 210 BC to 960 AD

气候变化及其影响研究是当前国际社会普遍关注的全球性问题。从粮食安全角度研究中国历史时期气候变化对朝代盛世及更替的影响,有助于从过程和机理的角度客观评价气候变化在朝代兴衰更替过程中的作用,从也可为深入认识未来气候变化的影响提供历史案例。本文首先界定了210 BC—960 AD(西汉至五代)期间中国社会的朝代更替及盛世时期,并以重建的温度序列和农业丰歉序列为据,研究了西汉至五代时期朝代更替及盛世与气候变化和农业丰歉的对应关系。西汉至五代,朝代更替多发生在冷期/寒冷阶段或者气候由暖转冷,农业收成相对歉收;朝代盛世多发生在暖期/温暖阶段和气候由冷转暖的位相上,农业收成相对丰收。从分裂到统一的朝代更替往往出现在百年尺度冷期末暖期初,气候由冷转暖、农业由歉转丰为乱世的结束提供了有利的气候条件和物质基础。而治世的结束、统一王朝的分裂则往往出现于百年际尺度的气候由暖转冷和农业由丰转歉。百年尺度及以上的气候冷暖交替和农业丰歉波动,对应着治世与乱世的更替。朝代治乱随气候变化的交替,一定程度上揭示出随气候变化的社会敏感时段,往往出现在由暖转冷的气候波动阶段以及百年际尺度上的气候由暖转冷时期。

Climate change and research of its impact is a current global issue that draws international attention. Studying the impact which Chinese ancient climate change had on dynastic flourishing ages and transitions from food safety perspective is helpful for objective evaluation on the mentioned effect through its process and mechanism. It also provides previous reference for deep understanding of climate change in the future. This essay first defines the periods of dynastic change and prosperity from 210 BC to 960 AD and studies the relations among dynastic prosperity, climate change and agricultural harvest. From 210 BC to 960 AD, dynastic climate change mostly went through cold ages or the period from warmness to coldness when farming was relatively poor. The transition from division to unification often came with a period from coldness to warmness when grain harvest increased, which provided materialistic and climatic condition for the end of social turbulence. Interestingly, the conclusion of an ordered dynasty and the division of unified dynasty often came with downing temperature after a centurial warmness and poor reaping after harvest. The fluctuation of grain harvest and climatic change corresponds with the transitions between a turmoil society and an ordered one, which reveals social sensitivity on climatic change.