The Road(s) to a Sustainable Contract Law: Three Approaches and Some Remaining Doubts

The idea of incorporating environmental sustainability into modern contract law is gaining traction. However, the feasibility of the project as a whole and the concrete changes needed remain largely unsettled and only incompletely explored. The present article contributes to the debate by identifying and critically analysing three strategies (top-down, bottom-up and nudging) to integrate ecological considerations into contract law. These approaches differ primarily in their reliance on private autonomy: the top-down model depends on mandatory state intervention, the bottom-up model is based on voluntary commitments and nudging strategies involve active legal intervention while preserving individual choice through opt-out mechanisms. Drawing on examples from European Union (EU) law and other jurisdictions, the article explores how each approach may operate in practice and assesses their respective strengths and limitations. The article finally concludes that a sustainable contract law is indeed attainable through these strategies (or a combination thereof) and that an ecological turn is already, albeit gradually, underway. Nevertheless, significant uncertainties remain – particularly regarding how best to balance environmental objectives with competing interests – raising further questions about the shape and viability of a truly sustainable contract law.