Simulated and Reconstructed Temperature in China since 1550 AD

In this paper, reconstructed decadal mean temperature anomaly series of 8 regions of China are compared to those generated in two multi-century simulations with a climate model, which was forced with time variable volcanic aerosols, solar output and atmospheric greenhouse gas concentrations. The two model simulations are rather similar but do exhibit some differences. Both the reconstructed and simulated developments of the temperature exhibit a “hockey-stick” pattern, with a marked increase of temperatures since the beginning of the twentieth century. The variations of time scales of a few decades are, however, mostly dissimilar in the historical and proxy-based account and also in the model data. An attempt is made to assess whether the warming during the twentieth century is within the range of “normal’’ variations related to solar and internal dynamical influences. It is found that the reconstructed data are well above the pre-industrial noise level of temperature fluctuations during most of the twentieth century. Within the adopted framework, only the increased greenhouse gas concentrations can account for these significantly elevated temperatures.