A Z-Number Fuzzy WENSLO–ALWAS Model for Evaluating Sustainable Airport Mobility and Climate-Transition Performance Using Secondary Data

Airports face increasing pressure to reduce their climate impacts while maintaining mobility, connectivity, operational capacity, and service quality. However, many airport sustainability assessments rely on expert judgments, narrow environmental indicators, or conventional multi-criteria decision-making models that treat heterogeneous public data as equally reliable. This study evaluates the sustainable mobility and climate-transition performance of 20 European airports using 18 criteria across six dimensions: airport access sustainability, low-carbon mobility, carbon transition, energy and resource efficiency, circularity, and operational pressure. Data from sustainability, annual, and integrated reports; Airport Carbon Accreditation records; official airport websites; public transport sources; and traffic statistics were integrated through a standardized airport–criterion data structure recording the source type, reporting year, unit, organizational boundary, calculation status, and assurance level of each observation. The data were then harmonized to common definitions and units before analysis. A Z-number fuzzy WENSLO–ALWAS framework was applied to represent each airport–criterion observation through two components: a fuzzy performance value and a fuzzy reliability value. This mechanism allows airport-specific, externally assured observations to exert stronger evidential influence than calculated, group-level, incomplete, or proxy-based values, thereby avoiding the equal treatment of data with different levels of credibility. The results provide reliability-adjusted airport rankings, dimension-level performance profiles, sensitivity analyses, robustness comparisons, and airport clusters. The findings indicate that airport sustainability performance depends not only on carbon reduction and accreditation maturity, but also on public transport accessibility, low-carbon mobility, resource efficiency, circularity, operational pressure, and reporting reliability. The empirical findings are specific to the selected European airports, while the proposed framework is transferable to other regions, subject to the recalibration of criteria, benchmarks, reporting conventions, and reliability rules. The study demonstrates how heterogeneous public sustainability data can be converted into transparent and defensible, reliability-aware inputs for airport benchmarking.