400 years of global-scale societal impacts of climate change

First study to give quantitative and scientific evidence about the impact of climate change on human societies in recent human history at global and continental scales

Hong Kong University Department of Geography professor Dr. David Zhang and researcher Mr. Harry Lee found that “historical war-peace, population and economic cycles are most likely induced by climate change.”

“Even though temperatures are increasing now, the same resulting conflicts may occur since we still greatly depend on the land as our food source,” said Peter Brecke, associate professor in the Georgia Institute of Technology’s Sam Nunn School of International Affairs and co-author of the study. Brecke assembled a database of 4,500 wars worldwide and population data between the years 1400-1900, with funding from the U.S. Institute of Peace.

The article by David D. Zhang, Peter Brecke, Harry F. Lee, Yuan-Qing He and Jane Zhang is to be published on 4 December 2007 in the Proceedings of the National Academy of Sciences of the United States of America (PNAS). It is entitled, "Global climate change, war and population decline in recent human history."

http://www.hku.hk/eroesite/html/ccc.pdf http://www.hku.hk/press/news_detail_5664.html
http://www.gtresearchnews.gatech.edu/newsrelease/climate-war.htm