A Novel Composite Index for Environmental Sustainability Based on Trade-Off Sensitivity Rather Than Absolute Performance

Environmental sustainability assessment has traditionally relied on composite indices that aggregate absolute performance metrics across economic, social, and environmental dimensions. However, such approaches often overlook the dynamic trade-offs inherent in sustainability transitions, where improvements in one area may compromise others. This paper proposes a novel conceptual framework for a composite index centered on trade-off sensitivity, rather than static absolute scores. By focusing on the responsiveness of sustainability outcomes to perturbations in interrelated factors, the index captures the vulnerability and resilience of systems to competing priorities. Drawing on recent literature, the framework synthesizes insights into multidimensional trade-offs and sensitivity analyses in sustainability metrics. The introduction delineates the limitations of existing indices, such as their failure to account for contextual dependencies and nonlinear interactions. The theoretical background reviews the evolution of composite indicators, emphasizing synergies and conflicts in ecosystem services and economic policies. The proposed framework outlines a sensitivity-based aggregation method that prioritizes relational dynamics over additive scores, enabling more nuanced policy evaluations. This approach advances theoretical understanding by integrating sensitivity thresholds as core components, fostering adaptive strategies for global sustainability challenges. Future implications include enhanced decision-making tools that balance short-term gains with long-term equilibrium.