JUNIPER: Joint use of nexus indicators for policy and environmental resilience–case study of Greece

Navigating sustainable development requires integrated modelling to quantify trade-offs between human systems and ecological boundaries. We introduce JUNIPER, a data-driven system dynamics model operationalising the Water, Energy, Food, Transport, Health, and Biodiversity (WEFTHB) nexus. We applied this framework to Greece during the baseline period from 2000 to 2019. JUNIPER's incremental contribution is a reproducible national-scale implementation that builds on an existing Water–Energy–Food (WEF) system-dynamics foundation by explicitly representing transport and linking cross-sector pressures to model-derived health and living-conditions indicators and model-derived, pressure-based biodiversity-risk proxies within a shared annual simulation. This operational integration supports the consistent examination of cross-sector trade-offs and co-benefits. Baseline results reveal a central cross-sector trade-off: a rising renewables share, declining energy-related CO 2 e emissions, and improved simulated longevity coexist with persistent irrigation-dominated water stress and deteriorating model-derived, pressure-based biodiversity-risk proxies. The integrated analysis highlights transport decarbonization and agricultural water/land management as candidate intervention domains for further scenario testing. Under the illustrative transport-transition assumptions, the model produced lower energy use, lower energy-related CO₂e emissions, and a lower model emissions-pressure aggregate, together with directionally favourable changes in the simulated health indicators and biodiversity-risk screening proxies. JUNIPER therefore provides a transparent, internally consistent historical baseline and a platform for conditional cross-sector policy screening under explicitly stated assumptions.