A chironomid-based record of temperature variability during the past 4000 years in northern China and its possible societal implications
- 1State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- 2MOE Key Laboratory of Western China's Environmental Systems, College of Earth Environmental Sciences, Lanzhou University, Lanzhou 730000, China
- 3Department of Geography, The University of Hong Kong, Hong Kong SAR, China
- 4School of Geographical Sciences, Guangzhou University, Guangzhou 510000, China
- 5Institute of Nihewan Archaeology Research, Hebei Normal University, Shijiazhuang 050024, China
Abstract. Long-term, high-resolution temperature records which combine an unambiguous proxy and precise dating are rare in China. In addition, the societal implications of past temperature change on a regional scale have not been sufficiently assessed. Here, based on the modern relationship between chironomids and temperature, we use fossil chironomid assemblages in a precisely dated sediment core from Gonghai Lake to explore temperature variability during the past 4000 years in northern China. Subsequently, we address the possible regional societal implications of temperature change through a statistical analysis of the occurrence of wars. Our results show the following. (1) The mean annual temperature (TANN) was relatively high during 4000–2700 cal yr BP, decreased gradually during 2700–1270 cal yr BP and then fluctuated during the last 1270 years. (2) A cold event in the Period of Disunity, the Sui-Tang Warm Period (STWP), the Medieval Warm Period (MWP) and the Little Ice Age (LIA) can all be recognized in the paleotemperature record, as well as in many other temperature reconstructions in China. This suggests that our chironomid-inferred temperature record for the Gonghai Lake region is representative. (3) Local wars in Shanxi Province, documented in the historical literature during the past 2700 years, are statistically significantly correlated with changes in temperature, and the relationship is a good example of the potential societal implications of temperature change on a regional scale.