The Making of International Environmental Law

The transboundary character of many natural resources, the continuous changes in the environment, together with the constant evolution of scientific findings are among the elements that deeply influence international environmental law. While traditionally the development of international environmental law is associated with Multilateral Environmental Agreements (MEAs), which since the Nineties have greatly contributed to shape the fundamental principles of this field, nowadays a more complex picture should be designed, which includes treaties and institutions pertaining to other legal areas of international law that are relevant to environmental matters. Contemporary environmental matters indeed are increasingly linked with economic development and human rights issues. These linkages are at the heart of the notion of sustainable development. In this polyhedric dimension, multiple branches of international law are directly and indirectly relevant to address the complexities of today’s most pressing environmental and sustainable development challenges. As for the economic-related fields, trade in environmental goods and services is one of the “bones of contention” under WTO negotiations, while vice versa under the climate regime, competitiveness is the underlying reason behind the impasse in the design of a new climate treaty. Moreover, bilateral and multilateral investment treaties increasingly recognize the relevance of environmental protection within their scope. As for the human right dimension, while environment-related cases are increasingly brought to human rights bodies, the independent expert of the UN Human Rights Council is currently studying “human rights obligations related to the enjoyment of a safe, clean, healthy and sustainable environment.” In such a context, the term “law” encompasses a wide range of normative instruments, which include treaty provisions and decisions adopted by MEAs treaty bodies, judgments and awards by judicial and quasi-judicial bodies, and their influence on the formation of customary environmental principles. In parallel, “lawmaking” describes the procedures through which these norms are created. Often these original and creative regulatory tools and processes do not meet the requirements and the definitions of traditional public international law, and have raised criticisms with regard to their legitimacy and effectiveness. In this perspective, this chapter focuses firstly on distinctive features of MEAs’ decision-making procedures that go beyond inter-state patterns. Secondly, it highlights how environmental matters are taken into account by other sectors of international law, namely trade and investment regimes and non-state actors’ rules, which – although not having a specific environmental mandate – influence the evolution of international environmental law.