Constructive Trusts and Intergenerational Equity in Human Rights Law: Beyond the Public Trust Doctrine

Abstract Human rights litigation increasingly confronts claims that environmental degradation violates duties owed to future generations, yet existing doctrinal frameworks struggle to give these intergenerational obligations concrete effect. This article argues that the constructive trust offers a more coherent and workable private-law architecture for intergenerational equity than the public trust doctrine that dominates current scholarship and climate litigation strategies. The article traces the intellectual genealogy of intergenerational obligation in ideas of stewardship, usufruct and equity, and shows how these motifs have been channelled into trust-based vocabularies. Following this, it surveys international and domestic case law in which courts acknowledge temporal dimensions of environmental harm but hesitate to constitutionalise a general public trust, and highlights four structural defects that render public trust theory jurisdictionally fragile and remedially weak. The latter portion of the article develops an account of constructive trust reasoning grounded in unjust enrichment and unconscionable retention of benefits and shows how this framework can be used to attach proprietary consequences to profits generated by rights-violating environmental conduct, without requiring recognition of future generations as current rights-holders. The article concludes that constructive trust logic is transferable across legal systems, because it aligns with civil-law regimes of unjust enrichment, patrimonies by appropriation and constitutional environmental rights provisions. It further contends that an intergenerational constructive-trust approach can supply some of the ‘missing architecture’ of intergenerational justice within contemporary human rights law.