Despite the fact that “heavy skies” (gravioris caeli) have been identified and legally classified as a serious concern since ancient times, air pollution still leads to millions of avoidable deaths and significantly impacts the climate. Today more than ever, the protection of people and a biophysical interconnected environment is the subject of a global discussion on the right to breathe clean air (RBCA) in international, interregional and national law. The Sustainable Development Goals (SDGs) as a global normative concept through SDG 3.9 target the reduction of air pollution, related deaths, diseases and the effects on climate change as a global health risk. But what is the exact status of the RBCA and who can claim access to justice from it?This paper attempts to classify RBCA as an exertable right in the realm of public law in a pan-European context and to shed light on the possibilities of its implementation and enforcement, also in connection with climate justice. To this end, its origins as philosophical thought or private right in Greek and Roman antiquity are first revealed and then connected in a doctrinal approach with the structures and legal bases of contemporary German law, which has contributed significantly to the emergence of the EU environmental legal framework. As a qualitative framing, the SDGs serve as an all-encompassing policy and target of the EU, whose agenda with SDG 16.3 also includes access to justice. The actual scope and enforceability of “clean air for all” is therefore determined not only by legislative but also through judicial review in the EU multi-level system. Additionally, international law forms an interpretive context of the RBCA. The Paris Climate Agreement and the Aarhus Convention as well as the “polluter pays principle” and the “common but differentiated responsibilities principle” will be examined for their effects on the granting and linking of rights. The paper also focusses on the connection of environmental and climate change claims with human rights obligations since this is a recurring assessment of the Court of Justice of the European Union (CJEU) and forms part of its rich jurisprudence. The results of the analysis show a varied picture. An independent human right to breathe clean air does not exist internationally or under European law to date. However, within the EU and in domestic German law, a right to clean air is attached to obligations under public and property law. This opens up a legal spectrum which not always leads to a comprehensive state liability. It is even more difficult for individuals or non-governmental organisations to gain access to justice under such legal framework. This is prevented in particular due to a lack of legal standing (locus standi) or further procedural requirements. Also substantially, the linking of fundamental rights to this very technical, environmental entitlement, both at European and national level, is associated with difficulties in its enforcement. Besides, effective enforcement regularly take unsatisfactorily lengthy periods of time to bring about change in the polluter’s behaviour and yet more time to bring about a real, effective and visible change to the situation, i.e. air pollution and its disease-inducing effects. The classification of RBCA as a right in the diverse context of the EU makes it possible to identify difficulties that may provide learnings for universal application, particularly with regard to the derivation and enforceability of the right. The paper also illustrates the status of the SDGs, which provide potential solutions, but ultimately have little more than a supportive function in this area, despite their multiple linkages in policy and legal instruments. Overall, the analysis reveals the weakness in the enforcement of an RBCA on the international, European and national levels
