There is an active debate regarding the influence that climate has on the risk of armed 15 conflict, which stems from challenges in assembling unbiased datasets, competing 16 hypotheses on the mechanisms of climate influence, and the difficulty of disentangling 17 direct and indirect climate effects. We use gridded historical conflict records, satellite 18 data, and land surface models in a structural equation modeling approach to uncover the 19 direct and indirect effects of climate on violent conflicts in Africa and the Middle East 20 (ME). We show that climate–conflict linkages in these regions are more complex than 21 previously suggested, with multiple mechanisms at work. Warm temperatures and low 22 rainfall direct effects on conflict risk were stronger than indirect effects through food and 23 water supplies. Warming increases the risk of violence in Africa but unexpectedly 24 decreases this risk in the ME. Furthermore, at the country level, warming decreases the 25 risk of violence in most West African countries. Overall, we find a non-linear response of 26 conflict to warming across countries that depends on the local temperature conditions. 27 We further show that magnitude and sign of the effects largely depend on the scale of 28 analysis and geographical context. These results imply that extreme caution should be 29 exerted when attempting to explain or project local climate-conflict relationships based 30 on a single, generalized theory. 31

中文翻译：

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气候对武装冲突具有截然不同的直接和间接影响

关于气候对武装冲突风险的影响存在积极的争论 15 ，这源于收集无偏见数据集的挑战，对气候影响机制的 16 种假设的竞争，以及解开 17 种直接和间接气候影响的困难。我们在结构方程建模方法中使用网格化的历史冲突记录、卫星 18 数据和地表模型来揭示气候对非洲和中东 20 (ME) 暴力冲突的 19 种直接和间接影响。我们表明，这些地区的气候-冲突联系比之前提出的 21 更复杂，有多种机制在起作用。温暖的气温和低降雨量 22 对冲突风险的直接影响强于通过食物和 23 供水的间接影响。变暖会增加非洲发生暴力的风险，但出乎意料的是 24 降低了中东的这种风险。此外，在国家层面，气候变暖降低了大多数西非国家的 25 暴力风险。总体而言，我们发现 26 冲突对各国间变暖的非线性响应取决于当地的温度条件。27 我们进一步表明，影响的幅度和符号在很大程度上取决于 28 分析的规模和地理背景。这些结果意味着 29 在试图根据单一的广义理论解释或预测当地气候冲突关系 30 时，应格外谨慎 29。31 我们发现 26 冲突对各国间变暖的非线性响应取决于当地的温度条件。27 我们进一步表明，影响的幅度和符号在很大程度上取决于 28 分析的规模和地理背景。这些结果意味着 29 在试图根据单一的广义理论解释或预测当地气候冲突关系 30 时，应格外谨慎 29。31 我们发现 26 冲突对各国间变暖的非线性响应取决于当地的温度条件。27 我们进一步表明，影响的幅度和符号在很大程度上取决于 28 分析的规模和地理背景。这些结果意味着 29 在试图根据单一的广义理论解释或预测当地气候冲突关系 30 时，应格外谨慎 29。31