This project will examine agrarian-nomadic migration across the Great Wall in response to climate change during the Little Ice Age (LIA, 1400-1900AD), especially at its three cold troughs (1430-1460AD, 1630-1660AD, and 1830-1860AD). In this frontier region of arid and semi-arid land, both farmers and nomads suffered from limited living resources because of climate change and sought survival through migration.

This project will further reveal how agrarian and nomadic societies changed from passive reactions towards more pro-active responses to the harsh climate, or from mutual struggle for survival towards somewhat collaborative development under environmental pressure. First, the project will construct a digitized comprehensive database on climate change, natural disasters like droughts, and bidirectional migration, as well as socioeconomic changes such as agrarian-nomadic conflicts, population growth, and food price during LIA. There are lots of reconstructed climate series and historical records regarding natural and socioeconomic phenomena, but this project distinguishes itself by its original effort to incorporate these varied data/records into a digital database to analyze their interrelations. Second, the project’s comprehensive database and quantitative analysis will present a panorama of agrarian-nomadic migration across the Great Wall. The relevant records will be turned into time series data and digital maps, according to the temporal and spatial information. Statistical tools and Geographic Information System will be applied to examine the spatiotemporal patterns of agrarian-nomadic migration against datasets of climate and socioeconomic changes as well as natural disasters during LIA. Third, this project will adopt the framework of social network analysis to examine agrarian-nomadic interactions through bidirectional migration particularly during three cold troughs, such as Ming government’s anti-Mongol migration strategies and construction of the Great Wall at the first cold trough, the Manchu’s rise and southern intrusion with migrant farmers’ assistance at the second cold trough, and the farmers’ migration from Northern China into Manchuria and Mongolia as nomads’ farming laborers at the third cold trough. The findings will supplement the quantitative results and may further develop the network analysis by adding the climate factor. The project will open a new ground in environmental studies of LIA’s impact on Eurasian history. It will provide the long-needed and more general environmental explanations for interactions between agrarian and nomadic civilizations. Its findings from China’s past will shed new light on the debate over the clash of civilizations in global context, and offer historical experience for the international collaboration in the fight against the global warming.