Measuring the effect of climate change on wars in history

ABSTRACT Since 2005, there have been an increasing number of large-N quantitative studies measuring the effect of climate change on wars in recent history. Those large-N studies are crucial in illuminating the close connection between the physical environment and human societies in a macro (i.e. long-temporal and large-spatial) historic perspective. Grounded on a large number of cases, those studies help evidence and generalize the societal impact of climate change. Nevertheless, this large-N approach is relatively new in academia, and there is not any standard practice as regards how the quantitative analysis of the pre-industrial climate-war nexus should be conducted. Some methodological issues remain open. In this study, those large-N studies of the climate-war nexus in the pre-industrial period are systematically reviewed. Some conceptual and methodological issues pertinent to the understanding and examination of the climate-war nexus are discussed. Suggestions and priorities for future research on the topic are also provided at the end of this paper. This study may provide deeper reflections and produce constructive insights about the relationship between climate change and wars, advancing progress in climate-war research.