Whether or not environmental migrants can move to other countries may heavily depend on the immigration policies of those countries. Such policies constitute a core aspect of national sovereignty and the question of the composition of the national community. To understand how migration flows caused by climate change may develop, one needs to understand what actual migration policies look like and how they function. It is still an open question to what extent nation states have introduced more restrictive or liberal policies over the last decades and are able to control migration flows.
