Thursday, March 22, 2012

New paper finds NW China was significantly warmer ~ 4000 to 5000 years ago

A paper published today in Climate of the Past finds that mean annual temperatures in the Tianshui Basin of NW China were approximately 2.2°C [3.9°F] higher than today during periods from 5200 to 4900 and 4800 to 4300 years ago. Alarmists claim that the much smaller 0.7C increase in global temperatures since 1850 is mostly man-made and that global warming 2°C above pre-industrial levels would cause catastrophic climate change. This study and many others show the earth has naturally warmed and cooled many times and to far greater extents than experienced over the past century without resulting in a 'runaway greenhouse effect' or catastrophic climate change.

Clim. Past, 8, 625-636, 2012
www.clim-past.net/8/625/2012/
doi:10.5194/cp-8-625-2012

The quantitative reconstruction of the palaeoclimate between 5200 and 4300 cal yr BP in the Tianshui Basin, NW China

N. Sun1,2 and X. Q. Li1,2
1The Laboratory of Human Evolution, Institute of Vertebrate Palaeontology and Palaeoanthropology, Chinese Academy of Sciences, 142 Xizhimenwai street, Beijing, 100044, China
2State Lab of Loess & Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Hi-Tech Zone, Xi'an, 710075, Shaanxi, China



Abstract. The quantitative reconstruction of the palaeoclimate is a prerequisite for understanding climate processes at time scales of centuries and millennia. Here, the coexistence approach (CA) was applied to reconstruct climatic factors quantitatively based on the fossil charcoal records between 5200 and 4300 cal yr BP in the Tianshui Basin, NW China. The CA analysis showed that the climate of the Tianshui Basin belonged to the northern subtropical zone between 5200 and 4300 cal yr BP. The mean annual temperature (MAT) was approximately 13.2 °C, and the mean annual precipitation (MAP) was approximately 778 mm between 5200 and 4900 cal yr BP. The MAT was approximately 13.2 °C, and the MAP was approximately 688 mm between 4800 and 4300 cal yr BP. The MAT was approximately 2.2 °C higher than today, and the MAP was approximately 280 mm higher than today from 5200 to 4900 cal yr BP. The MAT was also approximately 2.2 °C higher than today from 4800 to 4300 cal yr BP, while the MAP was approximately 196 mm higher than today. No abrupt cold event occurred between 5200 and 4300 cal yr BP; however, a drought tendency appeared after around 4800 cal yr BP.

Final Revised Paper (PDF, 4943 KB)   Discussion Paper (CPD)   

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