Unprecedented warming revealed from multi-proxy reconstruction of temperature in southern China for the past 160 years

Abstract

Using the southern limit of snowfall recorded in Chinese documents, chronologies of tree-ring width, and tree-ring stable oxygen isotope (δ¹⁸O), the annual temperature anomaly in southern China during 1850–2009 is reconstructed using the method of signal decomposition and synthesis. The results show that the linear trend was 0.47°C (100 yr)⁻¹ over 1871–2009, and the two most rapid warming intervals occurred in 1877–1938 and 1968–2007, at rates of 0.125°C (10 yr)⁻¹ and 0.258°C (10 yr)⁻¹, respectively. The decadal variation shows that the temperature in the moderate warm interval of the 1910s–1930s was notably lower than that of the 1980s–2000s, which suggests that the warming since the 1980s was unprecedented for the past 160 years, though a warming hiatus existed in the 2000s. Additionally, there was a rapid cooling starting from the 1860s, followed by a cold interval until the early 1890s, with the coldest years in 1892 and 1893. A slight temperature decline was also found from the 1940s to the late 1960s. This study provides an independent case to validate the global warming for the past 160 years and its hiatus recently, because the proxy data are not affected by urbanization.

摘要

利用历史文献中的降雪南界、树轮宽度及树轮稳定氧同位素(δ¹⁸O)等多种代用资料, 通过高低频信号分解回归再合成方法, 重建了1850–2009年华南地区年平均气温变化序列. 结果显示: 1871–2009年华南气温变化的线性趋势为0.47°C (100 yr)⁻¹, 其中1877–1938和1968–2007年两个时段升温最为强劲, 速率分别达到0.125°C (10 yr)⁻¹和0.258°C (10 yr)⁻¹. 年代际尺度上暖期包括1910s–1930s和1980s–2000s, 后者温暖程度显著高于前者, 是过去160年间的最暖时段, 不过2000年后增暖趋势有所停滞. 此外, 从1860s开始华南气温迅速下降, 随后的寒冷阶段持续到1890s, 其中1892和1893年达到最低值; 另一段降温期出现在1940s-1860s, 但降温速率较缓. 代用资料不受城市热岛效应影响, 基于此重建的温度序列独立于气温观测资料, 为研究20世纪全球变暖特征和近年来的增暖停滞提供了新证据.