The role of climate litigation in shaping environmental policy: a comparative analysis of global case law

Climate change litigation has emerged as a transformative mechanism for shaping environmental governance and enforcing accountability in the global fight against climate change. As governments and corporations often fail to meet international commitments or adopt effective mitigation strategies, courts have increasingly become arenas for climate action and instruments of policy reform. This thesis investigates how climate litigation contributes to the formulation, enforcement, and transformation of environmental policy through a comparative analysis of landmark global cases. It explores the ways in which judicial rulings influence national legislation, corporate conduct, and international climate governance, thereby redefining the intersection of law, human rights, and environmental responsibility. The study adopts a qualitative and comparative research design, examining key cases such as Urgenda Foundation v. The Netherlands (2015), Neubauer v. Germany (2020), Shell v. Milieudefensie (2021), Juliana v. United States (2015), Lliuya v. RWE (2015), Smith v. Denmark (2018), and Verein KlimaSeniorinnen v. Switzerland (2020). These cases are analyzed within a theoretical framework integrating the Public Interest Litigation Theory, Environmental Justice Theory, Legal Mobilization Model, International Climate Governance Model, and Policy Window Model. Together, these frameworks elucidate the legal, political, and social dynamics driving the rise of climate litigation and its broader implications for policy reform. The Public Interest Litigation (PIL) theory is central to this research, emphasizing the democratization of environmental law and the role of courts in protecting collective rights even where individual harm is diffuse or intangible. By expanding legal standing, PIL empowers citizens and organizations to demand governmental and corporate accountability for climate inaction. This theory explains how litigation can compel policy change by framing environmental protection as a shared public interest. Nevertheless, the thesis acknowledges that PIL’s effectiveness depends heavily on judicial independence and tThe International Climate Governance Model situates domestic litigation within a transnational framework. It demonstrates how national courts have invoked international treaties, especially the Paris Agreement (2015), to reinforce domestic environmental obligations. The integration of international norms into national jurisprudence signifies a new phase of “judicial globalization,” wherein domestic courts act as enforcers of international climate law. Yet, the model reveals a persistent challenge: the voluntary nature of Nationally Determined Contributions (NDCs) under the Paris Agreement often limits enforceability and uniform compliance. The absence of hard sanctions means that much of international climate governance relies on soft law mechanisms, transparency, and peer pressure rather than binding accountability. The Policy Window Model provides insight into how judicial rulings interact with political opportunity structures. Climate litigation often succeeds during periods of heightened public concern, environmental crises, or political transition—moments when problem recognition, policy proposals, and political will align. Courts have capitalized on such windows to compel policy reform, as seen in Urgenda v. The Netherlands, where judicial intervention coincided with growing societal awareness and international advocacy for stronger climate commitments. The research recommends further empirical investigation into post-litigation policy implementation, comparative analyses of legal systems, and the human rights dimensions of climate law. As the climate crisis intensifies, litigation will remain central to enforcing obligations, mobilizing action, and transforming policy frameworks toward a more equitable and sustainable future.