Spatial Scenarios With Real-Time Spatial Delphi and Asymptotic Consensus Analysis: An Application to Ten European Coastal Cities

Abstract

Recent climatic events, such as coastal erosion, floods, and elevated temperatures, threaten the planet's sustainability and the well-being of European coastal cities. These events are expected to increase significantly, emphasizing the urgent need for careful analysis to inform policy development and prevent dystopian scenarios. In the Futures Studies (FS) context, the development of future scenarios is essential for depicting long-term outcomes and facilitating effective planning, which can be achieved using various methods, including the Real-Time Spatial Delphi. This paper applies to the Delphi-based spatial scenario (DBSS), adopting a novel web-based open platform, to obtain spatial convergence of opinions among a panel of experts using spatial analysis and statistical indicators. The DBSS method was applied to 10 European coastal areas in seven different countries, involving 167 experts to assess climate impacts in 2050. This paper introduces for the first time, the concept of Asymptotic Theoretical Consensus to obtain a deeper understanding of the dynamic process, including duration, smoothness of convergence, and stability. The identified scenarios validate the proposed method and provide significant benefits to stakeholders, policymakers, local authorities, and governmental bodies in formulating efficacious strategies and confronting the challenges presented by climate change.