Understanding the interactions between climate, disease, and socio-political factors is crucial for a comprehensive understanding of the development of ancient East Asian history. This paper first examines the correlation between epidemics and climate recorded in historical documents, identifying the limitations of interpretations based solely on literary sources. To overcome these limitations, it suggests focusing on research from the natural sciences.
However, it also points out that previous natural science data and research methods have had several limitations. Nonetheless, it introduces the recent use of oxygen isotope ratios in dendrochronology as opening new possibilities. This method can yield precise results through collaboration with archaeology. Cooperation with historians is also essential. Therefore, close collaborative research among archaeology, history, and dendrochronology is required in the future.