The Mediterranean and other water-stressed regions are increasingly recognized as advanced laboratories of planetary limits, where climate change, land-system change, and biodiversity loss interact to jeopardize the interconnected Water-Energy-Food-Ecosystem-Health (WEFEH) nexus. The concept of a Safe Operating Space (SOS) for freshwaters, rooted in the planetary boundaries framework, offers a compelling lens for defining thresholds of availability, quality, and ecosystem stability beyond which irreversible damage may occur. Yet translating these thresholds into regionally adapted, policy-relevant, and operational tools remains a major scientific and governance challenge, compounded by the complexity of interlinkages among the different SOS components.

This session invites contributions that bridge the gap between global planetary boundaries and their local operationalization, from scientific frameworks and safe operating spaces at the global/regional scale, to digital tools, decision support systems, and living labs at the basin and field scale. We welcome studies on Nexus approaches (WEFE-H, Source-to-Sea) that move water governance from reactive to predictive management, leveraging digitalization, data science, and Earth observation. Contributions addressing the social and equity dimensions of these transitions, access, gender, and climate justice, alongside technical and modelling approaches, are strongly encouraged.

The session aims to bring together climate scientists, hydrologists, nexus and planetary-boundaries researchers, and practitioners to advance a shared operational agenda for water security under climate change, with a focus on the Mediterranean and other vulnerable regions worldwide.