In this paper, we investigate the long-term effects of climate change on the mobility of working-age people. We use a world economy model that covers almost all the countries around the world, and distinguishes between rural and urban regions as well as between flooded and unflooded areas. The model is calibrated to match international and internal mobility data by education level for the last 30 years, and is then simulated under climate change variants. We endogenize the size, dyadic, and skill structure of climate migration. When considering moderate climate scenarios, we predict mobility responses in the range of 70–108 million workers over the course of the twenty-first century. Most of these movements are local or inter-regional. South–South international migration responses are smaller, while the South–North migration response is of the “brain drain” type and induces a permanent increase in the number of foreigners in OECD countries in the range of 6–9% only. Changes in the sea level mainly translate into forced local movements. By contrast, inter-regional and international movements are sensitive to temperature-related changes in productivity. Lastly, we show that relaxing international migration restrictions may exacerbate the poverty effect of climate change at origin if policymakers are unable to select/screen individuals in extreme poverty.

中文翻译：

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气候迁移的地理

在本文中，我们调查了气候变化对工作年龄人口流动性的长期影响。我们使用的世界经济模型几乎覆盖了全球所有国家，区分了农村和城市地区以及洪水和未洪水地区。该模型经过校准，以匹配过去 30 年按教育水平划分的国际和内部流动数据，然后在气候变化变量下进行模拟。我们将气候迁移的规模、二元和技能结构内生化。在考虑温和的气候情景时，我们预测 21 世纪期间有 70-1.08 亿工人的流动性反应。这些运动大多是地方性的或跨区域的。南南国际移民反应较小，而南北迁移反应属于“人才外流”类型，并导致经合组织国家的外国人数量永久增加，幅度仅为 6% 至 9%。海平面的变化主要转化为强迫的局部运动。相比之下，区域间和国际运动对与温度相关的生产力变化很敏感。最后，我们表明，如果政策制定者无法选择/筛选处于极端贫困中的个人，放宽国际移民限制可能会加剧气候变化对贫困的影响。区域间和国际间的运动对与温度相关的生产力变化很敏感。最后，我们表明，如果政策制定者无法选择/筛选处于极端贫困中的个人，放宽国际移民限制可能会加剧气候变化对贫困的影响。区域间和国际间的运动对与温度相关的生产力变化很敏感。最后，我们表明，如果政策制定者无法选择/筛选处于极端贫困中的个人，放宽国际移民限制可能会加剧气候变化对贫困的影响。