Climate change and cascading effects on nomadic societies in the Mongolian Steppe (16th–18th Century)

Abstract

The impact of historical climate change on human societal processes through its influence on ecosystems remains unclear, particularly in the pastoral regions inhabited by nomadic civilizations. This study addresses this issue by examining the complex cascading effects between climate systems, grassland ecosystems, and nomadic social systems, based on climate change, grassland productivity, and the historical development of nomadic societies in the Mongolian grasslands during the 16th to 18th centuries. By reconstructing historical variations in temperature, precipitation, grassland net primary productivity (NPP), grazing carrying capacity, and population dynamics, this study reveals the profound impacts of declining temperature and precipitation during the Little Ice Age on the Mongolian grassland ecosystems and social systems. The study finds that in the 1550s, temperatures in the eastern and central Mongolian steppe dropped by 0.6–0.7 °C, which may have provided the environmental backdrop for the southward movement of the Mongolian Left Wing tribes and their increased trade interactions with southern agrarian societies. Between the 1590s and 1650s, climate change led to an 8 %–30 % decline in grazing carrying capacity across various pastoral regions compared to the 16th-century average, constituting a natural resource factor behind the widespread migration and turmoil of nomadic societies across the steppe. From the 1660s to the 1790s, grazing capacity in these regions increased again by 9 %–28 %, marking a period of renewed stability for nomadic societies on the steppe. This study also compares the social upheavals in the Mongolian grasslands with the global climate crises of the 17th century, finding that the historical changes in the Mongolian grasslands reflect the broader impacts of global climate fluctuations on the social transformations of pastoral nomadic civilizations. The transmission mechanism established in this study, in which climate change influences grassland ecosystems and subsequently impacts nomadic societies, not only sheds light on the role of climate change in historical nomadic societies but also deepens our understanding of the relationship between pre-industrial climate and human civilization development. Moreover, the findings of this study provide historical insights for the dynamic development of livestock farming under the current context of climate change in future.