Agriculture—especially grain cultivation—informed the primary environmental ground of imperial China (221 to 1912 ce) and was ideally intended to produce human habitat from state-supervised environmental change. The consequent political and socioeconomic development of the empire and its constituent dynasties was conditioned within larger global ecological contexts that can be abbreviated as two major climate shifts, the Medieval Warm Period (MWP, c. 1000–1300 ce) and the Little Ice Age (LIA, c. 1400–1900 ce). Before 1000 ce, China likely experienced a number of less prolonged alternations of cold and warm climate, such as the Sui-Tang Warm Period (650–700 ce).
Chinese empire’s adaptations in response were rooted in agriculture, augmented by agro-pastoral and pastoral measures mainly concentrated along and above north China’s steppe ecotone. Critical inputs for the sustainability of environmental relations were maintained throughout the imperial period and came from domestic and foreign sources—most critically including the fertile eroded silt of the north China Loess Plateau, the water resources of the Yellow and Yangzi river basins, a high-yield crop suite of both dryland and wet rice varieties, south China fast-growth tree species, and New World silver and highland crops. Ongoing development and exploitation of these resources across the succession of seven major—and over a dozen more localized—dynasties over two millennia allowed China’s population to expand at globally unprecedented rates, numbering from tens of millions around the year 0 ce to hundreds of millions during the 18th century. In the process, biodiversity—especially that of wild growth forest habitats—was steadily reduced from north to south, successively. The empire’s main resource base and population centers correspondingly relocated south of the Yangzi around the watershed Song (960–1279 ce) period, with the Grand Canal tapping both of China’s major rivers to deliver southern abundance as far north as Beijing by the Yuan (1279–1368 ce). Inner and Southeast Asian peripheries came under comparable agro-commercial developmental pressure only during the Ming–Qing period (1368–1912 ce). With the onset of the 19th century, however, destabilizing environmental pressures emerged across the empire, many of them paradoxically driven by once-effective adaptations.
