Relationship between climatic change and the nomadic southward migrations in eastern Asia during historical times

On the basis of data obtained from ancient Chinese chronicles, this study has established time series of southward and eastward migrations of the nomad people in the southern Mongolian grasslands and eastern central Asia from 190 B.C. to A.D. 1880 and found that there is a close relationship between climatic change and the migrations. We hypothesized that such a climate-migration relationship perhaps resulted from both livestock failure of the nomad people and crop failure of the Han Chinese during cold and/or dry climatic periods.