The settlement has, among other effects, stimulated the creation of territorial-based institutions. Among them, the “State”, which owns a central place, is sovereign and thanks to this authority, it practices its power on a territory on the population living in it with delimited borders. From then on, the forced mobility of the possible climatic nomad people collides with state borders. Indeed, climatic changes are provoking and will provoke population displacements, either within their country of origin or towards other sovereign territories. International law doesn’t provide for any specific regulations related to these climatic migrants. As it happens, looked at from the angle of the countries sovereignty, the population displacements caused by climatic changes concerns the affected countries’ authority and the authority of other countries likely to welcome those migrants. Internal population displacements for climatic reasons must respect affected people rights but fall within the sovereign authority of the affected country, with some exceptions. On the contrary, the submerged country sovereignty whose population is taking refuge on other land territories is involved. As for other countries, climatic migrations bring them to define with their own authority a policy regarding those migratory flows and occasionally make them contemplate or proceed to institutional adjustments about the presence of those migrants.