The Taiwanese scientist begins by noting that "Chinese historians often asserted that Emperor Tuoba Hong's decision to move his capitol from Pingcheng [which is today called Datong] to Luoyang in 494 AD was motivated by his personal bias towards Chinese ideals and values, along with other considerations such as politics, military defense, history and culture."  However, he says that "Sima Guang (1019~1086 AD) wrote in his book Zizhitongjian that 'the Emperor of Wei moved his capitol to Luoyang because of the severe climate that often occurred at Pingcheng, where snowfall in June and dust storms are common'."

In evaluating this analysis of a famous historian who lived some eight centuries nearer the event in question than more recent historians, Hsu found much corroborating data for Guang's assessment of climatic conditions at the time of the translocation of the Beiwei Dynasty's seat of government.  In addition to Guang's writings in Zizhitongjian, for example, he finds in Dilizhi of Suishu that Hezhenshan, a shrine mountain northeast of Datong, was covered with snow and frost in both winter and summer at the time of the capitol's relocation, and in Yulan that "since the peak of Hezhenshan was covered with snow during summer, birds were frozen to death," whereas such is not the case today, as Hsu reports that "the peak of Hezhenshan has been free of snow-cover from May to September for the last 30 years."

Hsu also writes that "the existence of 'ice-houses' built on Fuzhoushan in Nanjiang around 500 AD showed that the winter temperature and annual temperature during that time were approximately 2°C and 1°C lower, respectively, than that at present" (Zhu, 1979).  In addition, he reports that "tree-ring analyses on the Tibet Plateau support the conclusion of a cold-spell in the period between 300 AD and 600 AD" (Zhang et al., 2000), that "analyses of organic constituents for the lake sediment of Daguihu in Taiwan Province showed that there was an obvious cold and dry trend from 420 AD to 500 AD" (Luo et al., 1997), and that "analyses of stalagmites collected near Beijing also revealed that a cold period existed around 500 AD" (Tan et al., 2003).

Last of all, noting that frost events are meticulously recorded in the ancient documents of Weishu, Zizhitongjian and Shanxitongzhi, Hsu was able to compare the 30-year Beiwei Frost Season (BFS) of the period 479 AD to 509 AD with the Recent Frost Season (RFS) of the last 30 years.  In doing so, he found that "the BFS, on average, started 13.55 days earlier and ended 8.97 days later than the RFS," indicative of a 22.52-day extension of the BFS compared to the RFS.  And since "changes in the duration of frost period are directly related to air temperature," according to Hsu, "the additional 22.52 days of frost from 479 AD to 509 AD could correspond to a decrease of the lowest temperature by 2.48°C when compared with the RFS."

These observations suggest that the transference of governmental powers from the location of present-day Datong to Luoyang in 494 AD may indeed have been prompted by the severe cold of that time, which is part of the 210 to 560 AD cold period that Ge et al. (2004) describe as "the only one comparable with [the] Little Ice Age for the past 2000 years."  It is little wonder, therefore, that this earlier period of close-to-equivalent low temperatures is known far and wide as the Dark Ages Cold Period, but truly amazing that the world's climate alarmists claim that it never existed.  On the other hand, it's not so amazing, considering that to acknowledge the existence of the Roman Warm Period, Dark Ages Cold Period, Medieval Warm Period and Little Ice Age is to acknowledge the existence of the millennial-scale oscillation of climate that is likely responsible for bringing us the Modern Warm Period, totally independent of the 20th-century increase in the air's CO2 content.  Now that's something the world's climate alarmists truly can't acknowledge, for it undermines everything they've ever worked for in the political arena.

Sherwood, Keith and Craig Idso

References
Ge, Q., Zheng, J., Man, Z., Fang, X. and Zhang, P.  2004.  Key points on temperature change of the past 2000 years in China.  Progress in Natural Science 14: 730-737.

Hsu, S.  2004.  From Pingcheng to Luoyang - Substantiation of the climatic cause for capital relocation of the Beiwei Dynasty.  Progress in Natural Science 14: 725-729.

Luo, J.Y., et al.  1997.  Paleoclimatological information reflected from the constituents of lake sediment in Daguihu.  Academia Sinica, 99-104.

Tan, M., Liu, T.S., Hou, J. Qin, X., Zhang, H. and Li, T.  2003.  Cyclic rapid warming on centennial-scale revealed by a 2650-year stalagmite record of warm season temperature.  Geophysical Research Letters 30: 10.1029/2003GL017352.

Zhang, L.S., et al.  2000.  Global Change.  Higher Education Publishing Company, Beijing, China.

Zhu, K.Z.  1979.  Summaries of Climate Change in the Recent Five Thousand Years of China. Collected Articles of Professor Zhu, K.Z. Science Press, Beijing, China, pp. 475-498.