Environmental disruptions are generally recognized as an increasingly important factor of migration.
They can be both a cause and a consequence of population movements. It is a cause when people can no longer gain a secure livelihood in their homelands and are obliged to flee, having no other alternative.
It is a consequence when environmental degradation results from the mass movement of people, both in the departure and the receiving areas.

Environmental disruption can take many forms: brutal or slow-onset, natural or man-made, due to a single or cumulative changes. While these environmental disruptions can be extremely diverse, they have in common an affect on populations who are the most vulnerable and cannot adapt to a changing environment.

Migrations caused by drought and desertification share characteristics with the brutal displacements such as floods or tsunamis, in particular the absence of any legal status or organized protection. The relationship between environmental degradation and migration is important, complex, yet little understood

Desertification and Migrations, II International Symposium, 25-27 October 2006, Almeria, Spain. International Year of Deserts and Desertification (IYDD)