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Case studies on the impacts of extreme weather events at different spatial and temporal resolutions can help further the understanding of the impacts of climate change and serve as references for coping with future climate change challenges as well. We reconstructed the monthly time series data on social impacts of an extreme drought event in the Guanzhong area, Shaanxi Province, China, using newspaper records from 1928 to 1931. Changes in food substitutions, food prices, social unrest, and social resilience are analyzed to show how the drought affected the area. The results show that (1) the evolution of social impacts of the drought can be divided into five stages, and the variation in the impact magnitude is strongly influenced by the summer and autumn harvests; (2) the cumulative effects of the persistent drought are observed, and the level of social resilience declined rapidly and nonlinearly; and (3) there are two kinds of spreading patterns of drought’s impacts across natural, supporting, and humanity systems: hierarchical propagation and cascading effects. They act over different spatial and/or temporal scales and could provide the inspiration for the strategies designed to mitigate the impacts of climate change and extreme weather events today.

Based on the reconstructed temperatures, precipitation changes, and occurrences of extreme climate events, together with historical records on fiscal deterioration, food crises, and the frequencies of popular unrest, rebellions and wars, we identified three principal ways in which climate change contributed to the collapse in the Ming dynasty. Firstly, cooling, aridification, and desertification during a cold period destroyed the military farm system, which was the main supply system for the provisioning of government troops on the northern frontiers; these impacts increased the military expenditure from 64 % of total government expenditure in 1548–1569 to 76 % in 1570–1589 and thus aggravated the national fiscal crisis that occurred during the late Ming dynasty. Secondly, climate deterioration (e.g., cooling, aridification, and an increase in the frequencies of frost- and drought-related disasters, etc.) led to a 20–50 % reduction in the per capita production of raw grain in most areas of China, which resulted in widespread food crises and exacerbated the vulnerability of social structures during the last several decades of the Ming dynasty. Thirdly, the severe droughts occurring in 1627–1643 were a key trigger to the peasantry uprising. These droughts also played a significant role to promote the peasantry uprising, especially reviving the peasantry troops by recruitment of famine victims when they nearly perished in 1633 and 1638, and severely disrupting the food supply for the government troops, resulting in the final defeat of the government troops by the peasantry troops. This study contributes to an understanding of the climate-related mechanisms behind the collapse of the Ming dynasty, and provides a historical case study that enhances our understanding of the nature of interactions between climate change and social vulnerability.

Using a network of tree-ring data, we show that there had been significant growth decline in the 1920s and early 1930s throughout a wide area of northern China. This growth depression is indicative of a severe and sustained drought in the 1920s and early 1930s, which was then confirmed with a variety of historical and instrumental records including hydrological, meteorological, and documentary evidence. The 1920s drought had a devastating effect not only on agricultural productivity, hydrological resources and society in the affected areas, but also on natural vegetation, as inferred from the tree-ring network and historical records. This research offers a picture of the drought calamity during the 1920s and early 1930s in northern China, and demonstrates the potential to identify spatial anomalies of large-scale drought using tree-ring networks in the semi-arid and arid areas of northern China.