Correlation between climate and grain harvest fluctuations and the dynastic transitions and prosperity in China over the past two millennia

Abstract

The social impacts of climate change constitute an important field within the study of global change. The impacts of historical climate change on dynastic transitions and prosperity in China from a food safety perspective is a helpful research topic that contributes to a better understanding of the impacts, process, and mechanism of climate change, as well as a reference for projecting the impacts of climate change in the future. This study defined the periods of dynastic transitions and prosperity in China from 210 BC to AD 1910 and analyzed the relationships among dynastic transition or dynastic prosperity, climate change, and grain harvests. From 210 BC to AD 1910, dynastic transitions mostly coincided with cold ages or the periods that changed from warm to cold and dry or wet-to-dry periods when there was relatively poor harvest. In contrast, dynastic prosperity mostly coincided with warm ages or the periods that changed from cold to warm and wet or dry-to-wet periods when there was relatively bumper harvest. Meanwhile, the dynastic transitions from a divisive dynasty to a unified dynasty often came with a progressively warm phase on the century scale when grain harvests increased. Interestingly, the division of a unified dynasty often came with a progressively cold phase and poor harvests. Furthermore, changes in temperature and agricultural production may be one of the most important factors leading to the collapse of Tang Dynasty. In conclusion, the fluctuation of grain harvests and climate change correspond with the transitions between a tumultuous society and an ordered one, which reveals that the social sensitivity periods were often a result of a change to a colder climate on the century scale.

Social Impacts of Climate Change in Historical China

“…First, as many scholars have surmised (Hsu 1998;Lee et al 2008;Zhang et al 2005Zhang et al , 2006Ge 2011;Ge et al 2014;Pei et al 2014), the general characteristics of the impacts of historical climate change were negative in the cold periods and positive in the warm periods. On the centennial scale, the flourishing of economic and social health, population increase and territorial expansion generally occurred in the warm periods, with an inversion occurring during cold periods (Yin et al 2015(Yin et al , 2016bWei et al 2014Wei et al ,2015a. Among the 34 dynastic prosperity periods in the empirical China, 18 occurred in warm or relative warm periods, 26 of them occurred when the climate changed from cold to warm.…”

“…Among the 34 dynastic prosperity periods in the empirical China, 18 occurred in warm or relative warm periods, 26 of them occurred when the climate changed from cold to warm. On the other hand, 11 of the14 dynastic transitions periods occurred in cold or relative cold periods (Yin et al 2016b). The primary driver of the above processes are regarded to be warm conditions generally benefitting agricultural development.…”

Patterns in data of extreme droughts/floods and harvest grades derived from historical documents in eastern China during 801–1910

“…The climate in eastern China is dominated by the Asian monsoon, with a large precipitation variability, leading to drought and flood on a regional, and occasionally larger, scale (Ding et al, 2013). Data show that severe and extreme droughts have become more frequent in northeast China, northern China, and the eastern part of northwest China since the late 1990s and in southwest China between 2006 and 2013 (Zou et al, 2005(Zou et al, , 2010Zhai et al, 2010;and Yu et al, 2014). Assessment reports show that droughts affected, on average, 20.9×10 4 km 2 Z.…”

To what extent did changes in temperature affect China's socioeconomic development from the Western Han Dynasty to the Five Dynasties period?

“…Non‐climate change factors, such as natural population growth, saturation of farmland cultivation, and the economic and financial strength of the country, can trigger famines (Étienne and Sen, 1983; Farkas and Beczner, 2011). In addition to climate change, the occurrence of human migration, replacement of dynasties and social change are also profoundly affected by changes in population pressure and land carrying capacity, social unrest caused by corrupt governments, and reactionary rule, foreign invasions, and military strength (Lee et al ., 2008; Zhang et al ., 2011a,b; Lee and Zhang, 2013; Pei and Zhang, 2014; Pei et al ., 2015; Xiao et al ., 2015; Yin et al ., 2016a,b).…”

“…Studies on historical climate change based on this data source are distinctive and internationally recognized. With historical documents as the data source, several 10-year series of proxy indices for socioeconomic development have been reconstructed and provide long-term basic data for quantitatively analysing the social impact of climate change (Bai and Kung, 2011;Su et al, 2014Su et al, , 2016Wei et al, 2014Wei et al, , 2015aFang et al, 2015;Yin et al, 2015Yin et al, , 2016a. Hence, in this study, the temperature and social conditions in each decade are jointly analysed based on high-resolution data, long-term changes in temperature, and a series of socioeconomic proxy indices with the goal of determining how many periods from the Western Han Dynasty to the Five Dynasties of ancient China were mainly affected by changes in temperature and how many periods were controlled by socioeconomic factors.…”