The underlying idea of the notion ‘environmental refugee’ is simple: environmental problems make certain regions less fit for human habitation and people are therefore forced to migrate. However, much of the debate on environmental refugees is polarised. It is argued that this polarisation follows from two different perspectives. The first points to the responsibility of industrial countries with regard to their contribution to environmental problems. The second is interested in policies towards particular refugees. With regard to the latter perspective, there are two fundamental problems with the notion ‘environmental refugee’: the environmental cause cannot be easily disentangled from other
causal factors and the idea of environmental cause covers too many substantially different subgroups. These problems can be met by a more refined classification. The debate is focused for the most part on one category, namely 'deterioration refugees’. The main problem of this group is that they cannot be distinguished from the broader group of economic migrants. However, there is a subgroup of deterioration refugees in which the environmental cause can be separated from other causes, thus reinforcing this group’s claim to be helped.