Key points on temperature change of the past 2000 years in China

Temperature change of the past 2000 years in China is discussed based on the winter half-year temperature series of the past 2000 years in eastern China reconstructed recently, and other related studies. The main conclusions are as follows: (1) The Little Ice Age (LIA) in China began in the early of the 14th century (1320s) and ended in the beginning of the 20th century (1910s), which was composed of four evident cold stages and three short warming stages. The cold period in the Wei, Jin and South-North dynasties (210s～560s) was the only one comparable with LIA for the past 2000 years. (2) The Medieval Warm Period (MWP) in China began in the 930s and ended in the 1310s, which was composed of two warm stages over 100 years and a cold stage less than 100 years. (3) The climate in the Sui and Tang dynasties should be divided into two stages: the climate in the 570s～770s was as warm as that in the 20th century; while the temperature in the 780s～920s was lower than that in the 1950s～1970s. (4) In eastern China as a whole, winter half-year temperature variation with over 1 ℃ occurred between the cold and warm stages on centennial scale, while the changing rate exceeded 1.0 ℃ per century. (5) There exists an about 1350-year periodicity in the historical temperature change. Inferred from the periodicity, the most likely historical analogue for the warming in the 20th century is the warm stage of the Sui and Tang dynasties (570s～770s), instead of the Medieval Warm Period. (6) Although it was critically warm, the temperature of the 20th century in eastern China is still within the threshold of the variability of the last 2000 years.