Contemporary Issues in International Environmental Law: A Comparative Doctrinal Analysis of Climate Regulation and Litigation in the United States and the European Union

Abstract

Climate change affects business, society, governance, and the ecological environment, making it relevant to all fields of law rather than merely an environmental issue. It represents a systemic challenge that intersects with economic development, human security, public health, corporate conduct, and social justice. The 1992 United Nations Conference on Environment and Development (Earth Summit) marked a significant milestone in international environmental governance by bringing together political leaders, policymakers, and civil society actors to address emerging environmental concerns. Despite international climate commitments, global carbon dioxide emissions have remained persistently high over the last decade, accelerating global warming and intensifying ecological and humanitarian challenges. This highlights the limitations of soft-law approaches and the need for legally binding measures to reduce greenhouse gas emissions. Against this backdrop, this article undertakes a comparative doctrinal analysis of environmental law and climate governance in the United States and the European Union, examining how environmental activism, climate litigation, judicial intervention, and regulatory mechanisms have evolved into enforceable legal instruments for reducing carbon emissions and promoting environmental accountability. It argues that environmental activism has been a key catalyst in transforming environmental concerns into enforceable legal obligations through litigation, regulatory frameworks, and treaty-based commitments. Using a comparative legal approach, the study explores how environmental demands have been institutionalised through statutory duties, regulatory standards, and judicially enforceable rights. In the United States, activism has influenced environmental governance through public interest litigation, judicial interpretation, and regulatory accountability. In contrast, the European Union has adopted a more institutionalised and participatory model that incorporates procedural rights, public participation, and supranational oversight. The study employs a doctrinal legal research methodology supplemented by empirical evidence from climate surveys, UNEP reports, landmark judicial decisions, and key international environmental treaties. It concludes that environmental activism is an integral and enduring component of environmental law, shaping its evolution through doctrinal legal developments and judicial activism. This interaction creates a feed-forward loop whereby activism drives legal innovation and enforcement, while evolving legal frameworks further strengthen environmental advocacy, public participation, and accountability.