True to its mission, the second issue in volume two of Transnational Environmental Law (TEL) delves into the many and varied ways in which environmental governance is evolving beyond the state. The articles in this issue explore topics as diverse as: accountability in interpreting European Union (EU) framework norms; the role of third party actors in combatting transnational environmental crime; the rationales for socially responsible investing; the possibilities and pitfalls of using market-based tools to improve biodiversity conservation; and the need to develop a grundnorm premised on notions of planetary boundaries for our system of international environmental law. Yet, despite the range of topics and the depth of each of the individual articles, together they reveal an increasingly dominant set of questions in transnational environmental law. These questions concern the role that the market and market-based mechanisms can and should play in environmental protection and the varied ways in which non-state actors, whether in conjunction with or outside the parameters of the state, influence efforts to further environmental conservation and sustainability efforts. Secondary questions that arise within the context of exploring the influence of markets and non-state actors on environmental protection centre on questions of legitimacy and accountability. All of these inquires, however, are framed by two larger background questions: what is the underlying goal of international environmental law and concomitant systems of transnational environmental governance, and how can we go about creating governance systems that are more unified in their understanding of the baseline objectives and thus more symbiotic in their implementation? By engaging with questions about international environmental norms, the evolution of regional legal systems, and more overtly transnational governance challenges, this issue reminds us of the value of transnational environmental law as a framing mechanism for exploring the ways in which traditional and novel systems for environmental protection emerge, evolve, and intersect. In a world increasingly characterized by globalization and global environmental problems such as climate change, these intersections have become both more frequent and more intense, making it all the more important to find ways to conceptualize and respond to these challenges. The articles in this issue, in their individual and collective forms,