The collective securitisation of climate change: Implications for climate adaptation policy in the United Nations and European Union

Abstract This article advances research on ‘collective securitisation’ by theorising how ostensibly separate securitisation processes within different international organisations (IOs) interact and shape each other’s policy outcomes. Focusing on climate change adaptation within the United Nations (UN) and European Union (EU), the study uses an extensive database of documents (1972–2023) and interviews with officials to trace these dynamics. The analysis reveals that the UN initially securitised climate change through a risk-oriented approach emphasising long-term risk management, subsequently influencing the EU’s adaptation policies. Conversely, the EU intermittently reintroduced threat-based framing into the UN, highlighting recursive interactions between these organisations. Findings suggest key moments of cross-organisational influence, notably during the audience acceptance and policy output stages. By incorporating insights from transnational policy learning and norm diffusion, the paper theorises precisely how and when these interactions occur, enriching the analytical framework of Collective Securitisation. This article contributes to understanding how international organisations’ securitisation processes interact and shape climate adaptation policies, emphasising the nuanced interplay between threat-based and risk-based logics.