Scenarios of future international migration under climate change

Existing research indicates that climate change will predominantly affect internal (within-country) migration and displacement. However, there may also be effects on long-term international (cross-border) migration (Beine & Parsons, 2015; Hoffmann, Šedová, & Vinke, 2021; Kaczan & Orgill-Meyer, 2020). These are likely to be more indirect than effects on internal migration. For instance, an increasing number of severe weather extremes may deteriorate livelihoods and human security, and thus directly drive people to move within their country to seek other livelihood opportunities or safer living conditions. The same weather extremes may also increasingly damage the country’s economy and thereby stall its development, with effects on job opportunities, wages, the quality of infrastructure, etc. These impacts would be likely to affect international emigration from, and immigration to, the country. In this case, climate change influences migration patterns indirectly, acting through
macroeconomic factors. This report investigates the potential for such indirect effects. We present a scenario- based analysis of the future effects of climate change on international migration patterns, through the macroeconomic channel. For this analysis, we use an empirically calibrated, mechanistic model capturing the major drivers of international migration at a global level. It goes beyond previous, gravity-type models by accounting for a non-monotonic effect of incomes on emigration, which is potentially a major channel of indirect climate change impacts. At the same time, the model is still subject to a number of limitations; we therefore also present a new modelling approach developed within HABITABLE that addresses some of these limitations and offers a promising methodology to further analyze both direct and indirect effects of climate change on migration. The report summarizes the methods and main results of both our studies, while the attached papers provide further detail and discussion.