International Climate Migrant Policy and Estimates of Climate Migration

The architecture of international aid and climate finance should be reformed to address the needs of climate migrants. While humanitarian aid agencies that support some climate migrants are increasingly overburdened, climate migration has been underestimated and largely neglected by the United Nations Framework Convention on Climate Change (UNFCCC). The policy community has based a high-end estimate of 216 million potential climate migrants by 2050 on Groundswell (2021), but Groundswell does not address all drivers. It uses statistical methods to estimate internal migration from slow-onset drivers including crop yields, water supplies, and sea level rise, but the state of knowledge only permits rough, “back-of-the-envelope” estimates for other forms and drivers. Working out such estimates for sudden-onset drivers and for the remaining slow-onset drivers, if mitigation and adaptation are weak, I find that there could be about 500 million climate migrants by 2050. While the UNFCCC classifies climate migration under adaptation, few adaptation resources are devoted to migrants’ needs. Based on humanitarian aid expenses for other kinds of migrants, I estimate it could cost around $7000 per person to help climate migrants to rebuild their lives. At this rate, support for climate migrants would be a significant part of the total climate finance, and with organizational needs for supporting climate migrants being quite different from those for adaptation proper, it would make sense for the UNFCCC to address climate migration as a separate category on par with mitigation and adaptation.