Delayed warming in Northeast China: Insights from an annual temperature reconstruction based on tree-ring δ18O

Qiang Li; Yu Liu; Takeshi Nakatsuka; Ruoshi Liu; Qiufang Cai; Huiming Song; Shengjie Wang; Changfeng Sun; Congxi Fang

doi:10.1016/j.scitotenv.2020.141432

Delayed warming in Northeast China: Insights from an annual temperature reconstruction based on tree-ring δ¹⁸O

Sci Total Environ. 2020 Dec 20:749:141432. doi: 10.1016/j.scitotenv.2020.141432. Epub 2020 Aug 8.

Authors

Qiang Li¹, Yu Liu², Takeshi Nakatsuka³, Ruoshi Liu⁴, Qiufang Cai⁵, Huiming Song⁵, Shengjie Wang⁶, Changfeng Sun⁵, Congxi Fang⁵

Affiliations

¹ State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an 710061, China; Interdisciplinary Research Center of Earth Science Frontier (IRCESF) and Joint Center for Global Change Studies (JCGCS), Beijing Normal University, Beijing 100875, China. Electronic address: liqiang@ieecas.cn.
² State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an 710061, China; Interdisciplinary Research Center of Earth Science Frontier (IRCESF) and Joint Center for Global Change Studies (JCGCS), Beijing Normal University, Beijing 100875, China; School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an 710049, China. Electronic address: liuyu@loess.llqg.ac.cn.
³ Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8601, Japan.
⁴ School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
⁵ State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an 710061, China; Interdisciplinary Research Center of Earth Science Frontier (IRCESF) and Joint Center for Global Change Studies (JCGCS), Beijing Normal University, Beijing 100875, China.
⁶ College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, China.

PMID: 32805438
DOI: 10.1016/j.scitotenv.2020.141432

Abstract

Global warming has had an unprecedented impact on environmental changes and thus human life in mid-high latitude regions. As one of the areas most affected by global warming, Northeast China has suffered from a series of ecological crises, including warming-induced water deficits, permafrost thaw, and extended growing seasons. The change in annual average temperature (annual T) variations in Northeast China since the Industrial Revolution are still not fully understood, mainly because of the lack of long-term instrumental data and high-resolution annual T reconstructions. Here, we present the first annual T reconstruction (r = -0.683, p < .001, n = 60) for 1818-2012 in Northeast China, which may also be the first temperature reconstruction based on tree-ring δ¹⁸O in China. The reconstruction is significantly related to temperature variations over mid-high latitude Eurasia and agree (p < .01) with several long-term hydroclimatic reconstructions in the surrounding area. When the internal variability in the reconstruction was high, the decadal to multidecadal cycles were significant. Further analysis found that the reconstruction was mainly affected by the East Asian Summer Monsoon (EASM) and North Atlantic Oscillation (NAO). The reconstruction was significantly negatively correlated with several time series of annual T in the Northern Hemisphere, which showed that there is a substantial difference in annual T between Northeast China and other regions of the Northern Hemisphere. The difference mainly existed before the 1950s. From the 1850s to the 1950s, the annual T in Northeast China decreased slightly. However, extreme warming began in the 1950s in Northeast China, and this warming has been unprecedented during the past two centuries. If the warming trend since the 1950s continues, then it will lead to devastating disasters to forest and permafrost ecosystems in Northeast China.

Keywords: Annual T reconstruction; EASM; Global warming; NAO; Northeast China; Tree-ring δ(18)O.