Regional geographic factors mediate the climate-war relationship in Europe

It has been demonstrated in recent studies by that wars occurred with greater frequency in Europe in periods of cold climate over the past millennium, and food scarcity is the explanation. However, the issue of whether the climate-war relationship holds consistently across the European continent has been insufficiently explored. In the present study, we seek to advance the macroscopic understanding of the climate-war association in Europe via the statistical analysis of fine-grained paleo-climate and historical warfare data covering the period 1400–1999, with a specific focus on how regional geographic factors mediate the association. Our statistical results show that the climate-war correlation varied across Europe. At multi-centennial time-scale, temperature-war correlation was stronger in Eastern Europe, in part because of the region’s greater dependence on agriculture and in part due to the region’s prevailing continental climate. At multi-decadal to centennial time-scale, the temperature-war correlation in Europe was periodically distorted when population pressure was unleashed via a significant decline in the rate of population growth or through industrialization. Furthermore, the regional disparity in terms of population growth rate and pace of industrialization might be responsible for the diverse trends and trajectories of the temperature-war correlation in Eastern Europe and Western Europe. Our results may help to resolve some major controversies about the climate-conflict link. Copyright © 2015 Author(s). Published by Science & Knowledge House Ltd., UK.