The Legal Standing of Associations in European Climate Litigation Between Majoritarianism and Representativeness: Towards a Theory of Subsidiary Social Spheres

The rise of climate litigation shows a shift from traditional democratic processes to judicial avenues for environmental justice. Activist organizations are increasingly seeking judicial intervention to address deficiencies in climate policies, challenging the adequacy of majoritarian (political) decision-making. This phenomenon raises the question whether courts should hear such cases. With its 2024 KlimaSeniorinnen judgement, the ECtHR indicates a solution. By granting standing to the KlimaSeniorinnen association, but not to its individual members, the Strasbourg Court seems to draw a distinction between majoritarianism and representativeness or, in other terms, between quantitative and qualitative forms of interest representation. Although clear in establishing the standing criteria for climate activist associations, scholars and judges have found this decision lacking a broader theoretical justification. With the aim to fill this gap, this paper finds in the principle of (horizontal) subsidiarity the most fitting theoretical framework to acknowledge the role of civil society organizations in both complementing and ensuring accountability for the actions of public authorities in pursuing collective interests. In recognizing the plurality of (potentially competing) collective interests, this paper also outlines a theory of subsidiary social spheres and finds in strategic litigation its means of enforcement.