There is a disparity in the treatment accorded to environmental protection and human rights in international investment law, which belies the close relationship between these two areas of the law. A question therefore arises as to whether this relationship is likely to take on any significance in the international investment regime and, if so, what form this will take and what impact it will have. Human rights bodies have leveraged the discourse of human rights to achieve environmental ends. It is foreseeable that something similar might in future occur in the investment law context. When, how and indeed if this will occur will depend primarily on arbitrators’ approaches to the interpretation of international investment norms. In the meantime, states and investors should be aware of these issues and their potential significance in future investment disputes.