Temperature changes over the past 2000 yr in China and comparison with the Northern Hemisphere

Abstract

We use principal component regression and partial least squares regression to separately reconstruct a composite series of temperature variations in China, and associated uncertainties, at a decadal resolution over the past 2000 yr. The reconstruction is developed using proxy temperature data with relatively high confidence levels from five regions across China, and using a temperature series from observations by the Chinese Meteorological Administration, covering the period from 1871 to 2000. Relative to the 1851-1950 climatology, our two reconstructions show four warm intervals during AD1-AD200, AD551-AD 760, AD951-AD 1320, and after AD1921, and four cold intervals during AD 201-AD 350, AD 441-AD 530, AD781-AD950, and AD1321-AD 1920. The temperatures during AD981-AD 1100 and AD1201-AD 1270 are comparable to those of the Present Warm Period, but have an uncertainty of ±0.28°C to ±0.42°C at the 95% confidence interval. Temperature variations over China are typically in phase with those of the Northern Hemisphere (NH) after 1000, a period which covers the Medieval Climate Anomaly, the Little Ice Age, and the Present Warm Period. In contrast, a warm period in China during AD541-AD 740 is not obviously seen in the NH. © Author(s) 2013.