The graphic above is not from this paper/abstract, nor even the same time frame, but is from this one: A High-Resolution Absolute-Dated Late Pleistocene Monsoon Record from Hulu Cave, China I posted it because it seems relevant to the discussion of the paper below. I’m not an expert on cave and isotope dating, but I thought I’d provide a mix of resources to go along.
Here is some interesting reading. From the abstract, it suggests a correlation between monsoon and medieval warm period etc. But as we often see in papers that touch the edge of skepticism, there’s the obligatory line: “The sign of the correlation between the AM and temperature switches around 1960, suggesting that anthropogenic forcing superseded natural forcing as the major driver of AM changes in the late 20th century.”
I wonder. Here is another paper along the same lines, Holocene variability of the East Asian summer monsoon from Chinese cave records: a re-assessment sans the AGW suggestion.
Here is the link to the abstract below. Unfortunately, the full paper is behind the green wall of the AAA$, even though much of the research is from public institutions. Personally I think charging for access to such papers is flat wrong.
A Test of Climate, Sun, and Culture Relationships from an 1810-Year Chinese Cave Record
Pingzhong Zhang,1 Hai Cheng,2* R. Lawrence Edwards,2 Fahu Chen,1 Yongjin Wang,3 Xunlin Yang,1 Jian Liu,4 Ming Tan,5 Xianfeng Wang,2 Jinghua Liu,1 Chunlei An,1 Zhibo Dai,1 Jing Zhou,1 Dezhong Zhang,1 Jihong Jia,1 Liya Jin,1 Kathleen R. Johnson6
A record from Wanxiang Cave, China, characterizes Asian Monsoon (AM) history over the past 1810 years. The summer monsoon correlates with solar variability, Northern Hemisphere and Chinese temperature, Alpine glacial retreat, and Chinese cultural changes. It was generally strong during Europe’s Medieval Warm Period and weak during Europe’s Little Ice Age, as well as during the final decades of the Tang, Yuan, and Ming Dynasties, all times that were characterized by popular unrest. It was strong during the first several decades of the Northern Song Dynasty, a period of increased rice cultivation and dramatic population increase. The sign of the correlation between the AM and temperature switches around 1960, suggesting that anthropogenic forcing superseded natural forcing as the major driver of AM changes in the late 20th century.
1 Key Laboratory of Western China’s Environmental Systems (Ministry of Education), College of Earth and Environment Sciences, Lanzhou University, Lanzhou 730000, China.
2 Department of Geology and Geophysics, University of Minnesota, Minneapolis, MN 55455, USA.
3 College of Geography Science, Nanjing Normal University, Nanjing 210097, China.
4 Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
5 Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China.
6 Department of Earth System Science, University of California, Irvine, Irvine, CA 92697, USA.
hat tip to Dave Hagen