Relationships between temperature change and grain harvest fluctuations in China from 210 BC to 1910 AD

摘要

The impact of climate change on agricultural production is integral to understanding the impacts of historical climate change on society and the economy, which could provide historical references for dealing with current and future global climate change. Continuous proxy series of human activity that extend to more than 1000 years in the past are few, especially for high-resolution series. There was a lack of quantitative records of grain harvest in Chinese history except during the Qing Dynasty. Thus, it is difficult to reconstruct long-term and high-resolution agricultural production series. In this paper, the method developed by Su et al. (2014) is used to reconstruct the grain grade sequence with a 10-year resolution from 210 BC to 1910 AD in China, and the changes between temperature and grain yield grades are compared. A positive correlation between the winter half-year temperature departure and the grain yield from 210 BC to 1910 AD in China was found. The change of grain yield grades could be divided into five stages. The bumper harvest stages corresponded to the warm periods, and poor harvest stages corresponded to the cold periods. In both warm and cold periods, the grain yield grades assumed a trend of convergence with the temperature increase. The sensitivity of grain yield to temperature change became weakened over time from 210 BC to 1910 AD, perhaps due to the strengthened adaptive capacity of agriculture to temperature change, with the extension of fanning to southern China, progress of farming technology, and introduction of high-yielding crop varieties. Remote linkages between the agricultural change in China and the human civilization in Europe were found, implying the impacts of temperature change are globally synchronous.