Migration, immobility and displacement outcomes of extreme events in nature and society

There is growing international concern at an apparent rise in the severity and frequency of extreme environmental events as a manifestation of global environmental change, and that this could be linked with a future rise in the migration or displacement of human populations. However, recent approaches to migration influenced by environmental change call into question the notion that migration can be ascribed in a singular way to particular environmental causes or events. This paper undertakes a systematic review of evidence on population movements associated with weather-related extreme events. The paper demonstrates that in the face of extreme environmental events, it is important to distinguish between three outcomes migration, displacement, and immobility each of which interact and respond to multiple drivers. A narrow focus on any one of these misses the point: both those who move, and those who do not move, may find themselves trapped and vulnerable in the face of such extreme events; short-term displacement that goes hand-in-hand with loss of life, destruction of property and economic disruption poses significant risks not because it is 'environmental migration', but because it represents a failure of adaptation to environmental change.