Abnormal Climate and the Market Economy: the Relationship between Reconstructed Solar Radiation and Rice Price during the Famine of 1830s in Japan

Historically, climate change has played an important role in shaping human societies. Understanding past climate change is essential for human adaptation to future changes. Solar radiation, a key factor in Earth’s energy balance, hydrological cycle, and agricultural productivity, is crucial for understanding these changes. Our study focuses on reconstructing solar radiation from historical documents, shedding light on the historical impacts of climate variation and how past societies were influenced by and adapted to changing climate conditions. In Japan, many historical documents, including daily weather records from the 17th to 19th centuries, have been key to understanding historical climate variations. Utilizing these descriptions, we developed a method for reconstructing solar radiation. This method enabled us to analyze solar radiation patterns from 1821 to 1850, providing valuable insights into climate variations and their socio-economic impacts during this period. Our analysis, which focused on the 1830s Tempo Famine, revealed a clear relationship between climate variations and economic fluctuations. We found that the decrease in solar radiation during the summers of 1833, 1836, and 1838 corresponded with rising rice prices in Osaka, underscoring the impact on agricultural productivity and market dynamics. These findings suggest that the solar radiation pattern in the summer of 1836 dramatically influenced the severe famine, as evidenced by the unusual rise in rice prices. This study refines the understanding of the historical climate impacts on society and highlights the broader effects of climate variation on agriculture and market economies. This emphasizes the need to integrate climate information into economic analyses and could provide valuable insights for developing contemporary climate change policies and adaptation strategies.