Improving regional applicability of the UK shared socioeconomic pathways through iterative participatory co-design

Regional analyses of risks from climate change require reproducible, consistent and robust approaches to downscaling global socioeconomic scenarios, with coherent processes that work across multiple projects and communities. We address this need by developing an iterative approach to stakeholder-based Shared Socioeconomic Pathway (SSP) downscaling and co-design, enabling us to extend SSPs while maintaining their consistency from global to sub-national scales. We apply this approach to extend a set of SSPs for the United Kingdom, developing a broad range of user-oriented scenario products including (a) a set of key categories of socioeconomic drivers and their dimensions, (b) extended scenario narratives, (c) system diagrams, and (d) semi-quantitative trends of key socioeconomic indicators. Importantly, the co-design process outlined in this study was implemented fully online, providing valuable lessons on the implications of the online approach for participatory involvement, stakeholder inclusiveness and representativeness. In addition to presenting the approach and its resulting scenario products, we highlight how it contributes to adding detail and nuance, as well as geographic, temporal and sectoral extension to the scenarios. Furthermore, we discuss the benefits of the approach as a reproducible and robust roadmap to SSP downscaling, with respect to deepening the co-design process and increasing scenario legitimacy and validation.