Substantive Due Process as a Principle of Law to Protect the Right to a Safe Climate in a European Context

Often we think “due process” as a procedural requirement that a government must comply with before it imposes restraints or sanctions on an individual. In USA jurisprudence, in particular, due process also takes a substantive form. A limitation on liberty by government must also comply with a substantive dimension: there must be compelling reasons for government (or legislator) to limit individual liberty, otherwise it violates the substantive due process rights. Substantive due process rights have been applied in US climate litigation, Juliana v. US, where the plaintiffs claimed that the continued governmental permission, encouragement etc. to exploit or produce fossil fuels, in spite of the knowledge of the danger that CO2 emission would cause to the climate, violated their substantive due process rights. The District Court ruled that an individual has a right to be free from climate change on a catastrophic level. The right to a sustainable climate derived from ‘liberty’. Sustainable climate was the foundation of society “without which there would be neither civilization nor progress”. The principle seems also to exist in European law concerning protection of the climate. In Neubayer et al v Germany, the Federal Constitutional Court of Germany provided a similar reasoning although without direct reference to substantive due process. This paper addresses the principle of substantive due process in a European context. The paper discusses the potential for such a principle with basis in constitutional law and its limits under the European Convention on Human Rights (ECHR). The paper discusses substantive due process in the context of established principles of prevention and environmental impact assessment of public international law as well as the due diligence requirement of the principles of international law and of the Paris Agreement