Institute of Behavioral Science and Department of Geography, University of Colorado, Boulder, CO 80309-0483, USA.
Proc Natl Acad Sci U S A. 2012 Nov 6;109(45):18344-9. doi: 10.1073/pnas.1205130109. Epub 2012 Oct 22.
Recent studies concerning the possible relationship between climate trends and the risks of violent conflict have yielded contradictory results, partly because of choices of conflict measures and modeling design. In this study, we examine climate-conflict relationships using a geographically disaggregated approach. We consider the effects of climate change to be both local and national in character, and we use a conflict database that contains 16,359 individual geolocated violent events for East Africa from 1990 to 2009. Unlike previous studies that relied exclusively on political and economic controls, we analyze the many geographical factors that have been shown to be important in understanding the distribution and causes of violence while also considering yearly and country fixed effects. For our main climate indicators at gridded 1° resolution (~100 km), wetter deviations from the precipitation norms decrease the risk of violence, whereas drier and normal periods show no effects. The relationship between temperature and conflict shows that much warmer than normal temperatures raise the risk of violence, whereas average and cooler temperatures have no effect. These precipitation and temperature effects are statistically significant but have modest influence in terms of predictive power in a model with political, economic, and physical geographic predictors. Large variations in the climate-conflict relationships are evident between the nine countries of the study region and across time periods.
最近的研究关注气候趋势与暴力冲突风险之间的可能关系，但结果相互矛盾，部分原因是冲突措施和建模设计的选择不同。在这项研究中，我们采用地理细分的方法来检验气候与冲突之间的关系。我们认为气候变化的影响具有局部和全国性的特征，并且使用了一个包含 1990 年至 2009 年东非 16359 个个体暴力事件的冲突数据库。与之前仅依赖政治和经济控制因素的研究不同，我们分析了许多地理因素，这些因素在理解暴力的分布和原因方面非常重要，同时还考虑了每年和国家固定效应。对于我们在网格化 1°分辨率（约 100 公里）下的主要气候指标，偏离降水规范的湿润期会降低暴力风险，而干旱和正常时期则没有影响。温度与冲突之间的关系表明，远高于正常温度会增加暴力风险，而平均和较冷温度则没有影响。这些降水和温度的影响在统计学上是显著的，但在具有政治、经济和自然地理预测因子的模型中，其预测能力的影响较小。在研究区域的九个国家和不同时期，气候与冲突之间的关系存在明显的差异。
