Climate change, food shortage and war: a quantitative case study in China during 1500-1800

Abstract

Although global warming and its future possible consequences for human societies have been thoroughly examined in recent years, quantitative studies about the notable effects of climate changes upon human societies in history are almost absent. Recently, the authors scientifically explored the relationship between climate change and wars by comparing high-resolution paleo-climate reconstructions with known war incidences in history. They found that in most of the geographic regions worldwide war frequencies showed a cyclic pattern that closely followed the paleo-temperature changes. In this research, the authors proposed a conceptual model to exemplify how climatic fluctuations are translated into war peace cycles via socio-economic mechanism, with China during 1500 – 1800 to be a case study. The model was quantitatively verified by time series analysis and Pearson’s correlation analysis. Statistical results confirmed that, cooling impeded agricultural production brought about a series of social problems including food price inflation, then successively war outbreak, famine and population decline. The findings indicate that war-peace, population and price cycles in agrarian societies in recent centuries have been driven mainly by long-term climate change, which may challenge those socio-economic theories about historical cycles, human demography and wars. The observed temperature-war relationship may give some indication of future societal impacts from climate warming.