秦和西汉（公元前221年至公元24年）是中国社会繁荣的一个时代。然而，由于缺乏高分辨率的古气候记录，尚不清楚这一时期的农业增长是否与更有利的气候条件有关。对年轮记录的多参数分析和基于过程的生理模拟，提供了中国北方在公元前270-77年间稳定和持续湿润的气候条件的证据。
秦-西汉时期亚洲夏季季风区的降水比现在高18% ~ 34%。在向西北移动60至100公里（有时可能高达200公里）的农业和畜牧业边界中，持续潮湿的条件可能增加了粮食产量，促进了2200年前左右的社会经济繁荣。自20世纪80年代以来，中国西北干旱地区西部的逐渐湿润趋势与历史气候相似，这表明在当前的气候变化下，至少在短期内，区域环境和农业系统可能会再次出现类似的效益。
附：英文原文
Title: Persistent humid climate favored the Qin and Western Han Dynasties in China around 2,200 y ago
Author: Qin, Chun, Yang, Bao, Bruning, Achim, Charpentier Ljungqvist, Fredrik, Osborn, Timothy J., Shishov, Vladimir, He, Minhui, Kang, Shuyuan, Schneider, Lea, Esper, Jan, Büntgen, Ulf, Grieinger, Jussi, Huang, Danqing, Zhang, Peng, Talento, Stefanie, Xoplaki, Elena, Luterbacher, Jürg, Stenseth, Nils Chr.
Issue&Volume: 2024-12-23
Abstract: The Qin and Western Han dynasties (221 BCE to 24 CE) represent an era of societal prosperity in China. However, due to a lack of high-resolution paleoclimate records it is still unclear whether the agricultural boost documented for this period was associated with more favorable climatic conditions. Here, multiparameter analysis of annually resolved tree-ring records and process-based physiological modeling provide evidence of stable and consistently humid climatic conditions during 270 to 77 BCE in northern China. Precipitation in the Asian summer monsoon region during the Qin–Western Han Dynasties was ~18 to 34% higher compared to present-day conditions. In shifting agricultural and pastoral boundaries ~60 to 100 km northwestward, possibility up to 200 km at times, persistently wetter conditions arguably increased food production, contributing to the socioeconomic prosperity around 2,200 y ago. A gradual wetting trend in the western part of arid northwestern China since the 1980s resembles the historical climate analogue, suggesting that similar benefits for regional environmental and agricultural systems may reoccur under current climate change, at least in the near term.
DOI: 10.1073/pnas.2415294121
Source: https://www.pnas.org/doi/abs/10.1073/pnas.2415294121