Ocean/atmosphere interaction and Malthusian catastrophes on the northern fringe of the Asian summer monsoon region in China, 1368–1911

How and to what extent are human societies affected by climate change? There has been a growing body of research using big historical data and statistical analyses to provide scientific answers to this inter-disciplinary research question. However, quantitative analysis measuring the historical demographic impact of ocean/atmosphere interaction is still scanty. Here we use 544 years (1368–1911) of historical records to trace the demographic impact brought about by ocean/atmosphere interaction in Shaanxi, located on the northern fringe of the Asian summer monsoon region in China. Our results show that: (1) North Atlantic Oscillation (NAO) and El Niño Southern Oscillation (ENSO) caused Malthusian catastrophes mainly through drought at the inter-annual scale; (2) drought reinforced the synchrony of various Malthusian catastrophes at the inter-annual to multi-decadal scale; and (3) the unusual cycles of NAO drove drought and various Malthusian catastrophes in the cold 1550–1730 period at the multi-decadal scale. This study represents a pioneering attempt to quantitatively assess the demographic impact caused by the ocean/atmosphere in historical China. Our findings may help to conceptualise the climate–human nexus in those ecologically marginal regions that are impacted by ocean/atmosphere interaction, and to explain the synchrony of social crisis in Eurasia in the 17th century.