Tensions between economic interests and environmental protection have assumed crisis proportions in awareness at every level of society. In particular, the World Trade Organization has become entangled in controversies related to legitimacy, democracy, environmental protection, and fragmentation of international law, fuelling a contentious debate on the use (or abuse) of environmental norms at the WTO. To a greater degree than any comparable treatment, this book focuses on the role of the WTO dispute settlement system in addressing trade-environment conflicts. Highlighting the ways in which environmental issues challenge the legitimacy of WTO jurisprudence, it considers such relevant core issues as the following: challenges posed to the WTO by so-called "linkage" issues, such as environmental protection, labour, and investment; to what extent the WTO can apply rules of international law (e.g., environmental ones) that are not contained in the WTO agreements; and concerns over the Dispute Settlement System's lack of democratic accountability in matters of great public interest. The study analyses in detail the role of international environmental law in three key WTO cases, namely the Shrimp-Turtle, Hormones and Biotech disputes. This deeply informed and thoughtful book is of special importance for its proposals on how the WTO dispute settlement system can improve its legitimacy while respecting the limits of its mandate. It will be welcomed by international trade attorneys, environmental lawyers, concerned academics and students, and government officials in both trade and environmental policy.