Time lag in the climate change, war, and population relationship: A quantitative analysis

Wars became more frequent in a cold climate at the macro-historical scale. However, war peaks and their associated population collapses appeared ~20–30 years after the commencement of a cold climate. Following Zhang et al.'s (2007a) conceptual model, this paper sought to further examine the climate-war-population time lag by using mathematical means. Result was: the relatively slow natural population adjustment to the climate-induced fluctuations in agricultural production generated the time lag between the climate, war, and population cycles in historical agrarian societies. This finding may lend a new dimension to the classic Malthusianism and have current implications to the less developed countries near the tropics. Copyright © 2009 Taylor & Francis.