The significant moral and normative force which comes with asserting that a particular social claim is a ‘human right’ has led to a variety of interest groups and organisations employing human rights rhetoric in advocating for social, legal or political change. While this technique has proven successful for mobilising public support, it can lead to confusion regarding the status of particular human rights in international law, and it could undermine the status of human rights as a whole. While States are free to develop and expand the law into new areas, this paper argues that caution must be exercised in the expansion and development of human rights law. In order to illustrate the issues surrounding the uncritical proliferation of human rights, this paper takes as a case study the right to a good environment. The paper identifies various considerations which are relevant to an assessment of whether the right should be recognised under international law. It first looks to human rights theory to identify the sorts of claims which are appropriate for recognition as human rights. It then draws on a range of normative, practical and political considerations, which are relevant to the question of whether the proposed right could be effectively defined, implemented and enforced. After examining the right to a good environment against these criteria, the paper concludes that recognition of the right cannot be justified and that international attention should instead focus on improving the application of existing rights to environmental issues.