Climate change and biodiversity loss are interconnected crises that threaten the resilience of societies and economies. Conventional policy evaluation frameworks, often based on narrow economic metrics, fail to capture systemic risks, long-term disruptions, and broader societal dimensions. The DECIPHER project responds to the need for effective policy measures that address escalating climate, environmental, and economic challenges globally. It tackles decision-making shortcomings by creating a holistic framework that integrates advanced economic and biophysical modelling, empirical social science insights, and participatory governance. Its overarching aim is to transform how climate and environmental policies are assessed and designed, moving beyond static cost-benefit approaches toward dynamic, multi-criteria evaluations that incorporate risk, resilience, and opportunity. The project also seeks to increase transparency in tools supporting policymaking and improve the use of economic models in policy design and evaluation. The framework embeds environmental damages and climate-related financial risks into economic decision-making while enhancing models to reflect behavioural dynamics, technological innovation, and systemic vulnerabilities. Co-created with stakeholders from government, industry, academia, and civil society, DECIPHER ensures transparency and legitimacy throughout its processes. By applying this framework to real-world EU policies, the project generates actionable insights that strengthen Europe’s capacity for evidence-based, inclusive, and forward-looking environmental governance, contributing to a sustainable and climate-resilient future.