文档介绍：Global climate change, war, and population
decline in recent human history
David D. Zhang*†, Peter Brecke‡, Harry F. Lee*, Yuan-Qing He§, and Jane Zhang¶
*Department of Geography, University of Hong Kong, Pokfulam Road, Hong Kong; ‡Sam Nunn School of International Affairs, ia Institute of
Technology, Atlanta, GA 30332-0610; §Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Science,
Lanzhou 730000, Gansu, China; and ¶Department of Anthropology, University College London, London WC1E 6BT, United Kingdom
Edited by Paul R. Ehrlich, Stanford University, Stanford, CA, and approved October 23, 2007 (received for review April 4, 2007)
Although scientists have warned of possible social perils resulting of the periods of nationwide unrest, population collapse, and
from climate change, the impacts of long-term climate change on dynastic change occurred in the cold phases of this period
social unrest and population collapse have not been quantitatively (11–13). As a result of recent scientific breakthroughs in estab-
investigated. In this study, high-resolution paleo-climatic data lishing more precise paleo-climatic records [see supporting
have been used to explore at a macroscale the effects of climate information (SI) Text], we extend the earlier study to the global
change on the outbreak of war and population decline in the and conti