Studies investigating migration as a response to climate variability have largely focused on rural locations to the exclusion of urban areas. This lack of urban focus is unfortunate given the sheer numbers of urban residents and continuing high levels of urbanization. To begin filling this empirical gap, this study investigates climate change impacts on U.S.-bound migration from rural and urban Mexico, 1986-1999. We employ geostatistical interpolation methods to construct two climate change indices, capturing warm and wet spell duration, based on daily temperature and precipitation readings for 214 weather stations across Mexico. In combination with detailed migration histories obtained from the Mexican Migration Project, we model the influence of climate change on household-level migration from 68 rural and 49 urban municipalities. Results from multilevel event-history models reveal that a temperature warming and excessive precipitation significantly increased international migration during the study period. However, climate change impacts on international migration is only observed for rural areas. Interactions reveal a causal pathway in which temperature (but not precipitation) influences migration patterns through employment in the agricultural sector. As such, climate-related international migration may decline with continued urbanization and the resulting reductions in direct dependence of households on rural agriculture.

中文翻译：

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气候变化是墨西哥农村和城市移民的驱动因素


调查移民作为应对气候变化的反应的研究主要集中在农村地区，而排除了城市地区。鉴于城市居民数量庞大且城市化水平持续较高，这种对城市关注的缺乏是不幸的。为了填补这一实证空白，本研究调查了 1986 年至 1999 年气候变化对墨西哥农村和城市前往美国的移民的影响。我们采用地统计插值方法构建两个气候变化指数，根据墨西哥 214 个气象站的每日气温和降水读数来捕获温暖和潮湿的持续时间。结合墨西哥移民项目获得的详细移民历史，我们模拟了气候变化对 68 个农村和 49 个城市的家庭移民的影响。多级事件历史模型的结果表明，研究期间气温变暖和过量降水显着增加了国际移民。然而，气候变化对国际移民的影响仅在农村地区观察到。相互作用揭示了温度（而非降水）通过农业部门就业影响移民模式的因果路径。因此，随着城市化的持续发展以及家庭对农村农业直接依赖的减少，与气候相关的国际移民可能会减少。