An integrated framework for wildfire risk assessment under climate change: empirical validation and application in Greece

Abstract. Climate change is increasing the frequency and severity of wildfires across the Mediterranean, posing growing risks to ecosystems, infrastructure and human communities. Robust methodologies for assessing wildfire risk under both present and future climate conditions are therefore essential to support climate change adaptation. In this study, we develop and empirically validate an integrated wildfire risk assessment framework for Greece following the Intergovernmental Panel on Climate Change risk concept. Wildfire hazard, exposure and vulnerability are represented through climate, environmental and socioeconomic indicators, while alternative hazard representations and aggregation approaches were systematically evaluated against observed wildfire occurrence to identify the most accurate methodological configuration. The validated framework was then applied to assess wildfire risk for the reference period (1995–2014) and under SSP2-4.5 and SSP5-8.5 scenarios for the near (2041–2060) and distant (2081–2100) future. The results demonstrated that aggregation behaviour plays a critical role in determining the predictive performance of composite wildfire risk indices, with an Ordered Weighted Averaging (OWA) approach providing a statistically significant improvement over conventional linear aggregation. Analysis of component contributions identified hazard as the dominant contributor to wildfire risk across most municipalities, although exposure and vulnerability remained important determinants of the final risk patterns. Future projections indicated a widespread increase in wildfire risk throughout Greece, with the largest increases occurring under the high-end SSP5-8.5 scenario in the late century. The proposed framework provides a transparent and empirically validated basis for wildfire risk assessment that can support climate change adaptation planning at national and regional scales.