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Two Thousand Years of Chinese Climate
Yang, B., Braeuning, A., Johnson, K.R. and Yafeng, S.  2002.  General characteristics of temperature variation in China during the last two millennia.  Geophysical Research Letters 29: 10.1029/2001GL014485.

What was done
Using nine separate proxy climate records derived from peat, lake sediment, ice core, tree ring and other proxy sources, the authors compiled a single weighted temperature history for China spanning the past two thousand years.

What was learned
The composite temperature record revealed five distinct climate epochs: a warm stage from AD 0 to 240 (the tail-end of the Roman Warm Period), a cold interval between AD 240 and 800 (the Dark Ages Cold Period), a return to warm conditions from AD 800-1400 (which included the Medieval Warm Period between AD 800 and 1100), a cool interval between 1400 and 1820 (the Little Ice Age), and the current warm regime (the Modern Warm Period) that followed the increase in temperature that began in the early 1800s.  Another important finding of the study was the fact that the warmest temperatures of the past two millennia were observed during the second and third centuries AD.

What it means
The results of this study demonstrate that the so-called unprecedented warmth of the 20th century is a myth.  Indeed, the warmth of this period was but a manifestation of naturally-induced regularly-recurring conditions similar to those experienced in prior millennia.  These results also serve as a testimony against those who would deny the existence of an extensive (hemispheric or global) Medieval Warm Period and Little Ice Age, as well as an extensive Roman Warm Period and Dark Ages Cold Period, as well as natural cyclical climate changes.  It's time for such folks to wake up and recognize the (likely) solar-induced dynamic nature of real-world climate!

Reviewed 25 September 2002