5Working Group I of the Intergovemmental Panel on Climate Change. Summary for Policymakers: A Report of Working Group l of the Intergovernmental Panel on Climate Change. /index.htm.
6Mann M E, Bradley R S, Hughes M K. Northern Hemisphere temperature during the past millennium: inferences,uncertainties, and limitations. Geophysical Research Letters, 1999, 26(6): 759-762.
7Briffa K R, Osbom T J. Paleoclimate: blowing hot and cold. Science, 2002, 295: 2227-2228.
8Briffa K R. Annual climate variability in the Holocene: interpreting the message of ancient trees. Quaternary Science Reviews, 2000, 19: 87-105.
9Crowley T J, Lowery T S. How warm was the medieval warm period? AMBIO, 2000, 29(1): 51-54.
10Jones P D, Briffa K R, Barnett T P et al. High-resolution palaeoclimate records for the last millennium: interpretation, integration and comparison with general circulation model control-mn temperatures. Holocene, 1998, 8: 455-471.
7Chun Chang Huang, Shi Chao Zhao, Jiangli Pang, et al. Climatic aridity and the relocations of the zhou culture in the southern loess plateau of china [ J ]. Climatic Change,2003,61 : 361 - 378.
8Chun Chang Huang, Jiangli Pang, Pinghua Li. Abruptly increased climatic aridity and its social impact on the loess Plateau of China at 3100aB. P. [J]. Journal of Arid Environments,2002,52:87 -99.
9Chun Chang Huang, Jiangli Pang, Qunying Zhou, et al. Holocene pedogenic change and the emergence and decline of rain - fed cereal agriculture on the Chinese Loess Plateau[ J ]. Quaternary Science Reviews,2004, 23:2525-2535.
10Chun Chang Huang, Jiangli Pang, Shu' e Chen, et al. Holocene dust accumulation and the formation of polycyclic cinnamon soils (luvisols) in the chinese loess plateau [ J ]. Earth Surface Processes and Landforms,2003, 28:1259 -1270.
