Purpose In recent years, the manifestation of the effects of climate change in coastal zones has prompted governments to mobilize and propose adaptation measures to reduce the vulnerability of their populations. For the governments responsible for the implementation of climate policies, adaptation still represents a novel field of action. The purpose of this paper is to show, via the example of Quebec’s coastal zone, how the transformation of public action relating to adaptation remains difficult. Design/methodology/approach For this case study, a qualitative method which combines documentary analysis and semi-directed interviews was selected. Findings The study shows how adaptation becomes a new issue in public action for the different authorities dealing with the effects of climate change in Quebec’s coastal zone. However, the results show that, as with other public policies, path dependence and incrementalism can be observed and limit the scope of public action and of the transformational processes in the field of adaptation. The technical–scientific approach to risk management is dominant, and the adaptation is not approached in a transversal way, despite its importance. Finally, concrete adaptation initiatives appear to be mostly relegated to the local scale, in an informal decentralization process. Originality/value This study contributes to improve climate action by favouring a reflection on the consideration of the conceptual and theoretical framework in the climate change adaptation literature and offers decision-makers and practitioners keys to the understanding of mechanisms underlying public action in the field of adaptation.