The aim of this chapter is to examine the legal framework for the protection of the environment of the polar regions by applying two models: the decentralised-relational model and the institutional-communitarian model. Under the decentralised-relational model, there is no centralised machinery for legislating and implementing environmental norms. The protection of the Arctic environment relies on the decentralised-relational model. This model provides an example of the individual application of Georges Scelle’s theory of the law of dédoublement fonctionnel. By contrast, the protection of the Antarctic environment rests on the institutional-communitarian model. Under this model, the consultative parties to the Antarctic Treaty System collectively protect the Antarctic environment as a guardian of the international community. The institutional-communitarian model relies on the institutional application of the law of dédoublement fonctionnel. The two models coexist in the polar law system.