Within the framework of the Kras Firewall 5.0 project, an assessment of current and future climate change in the cross-border Karst area between Italy and Slovenia has been carried out, with a particular focus on climate factors influencing the occurrence and intensity of wildfires. The analysis provides an important scientific basis for subsequent project activities, especially for hazard and vulnerability assessments and the development of joint cross-border measures to reduce wildfire risk.
The report is based on a review and comparison of climate data and projections provided by the Slovenian Environment Agency (ARSO) and the Regional Environmental Protection Agency of Friuli Venezia Giulia (ARPA FVG), as well as on open climate data from the EURO-CORDEX project. Particular attention is given to the compatibility and comparability of datasets between the two countries and their applicability in geospatial analyses.
The findings confirm that climate change on the Karst is already clearly observable, particularly through rising temperatures, an increasing frequency of heatwaves and tropical nights, and a growing variability in precipitation patterns. Future climate projections, especially under higher emission scenarios, indicate continued warming and increased summer heat and drought stress, significantly affecting forest ecosystem vulnerability and increasing the risk of wildfires.
The analysis also highlights the importance of coordinated cross-border management of climate and environmental data and the need for a shared strategic approach to wildfire prevention and management in the Karst region.
Key findings
Average temperatures on the Karst have been steadily increasing for several decades, particularly during the summer season.
The number of hot days (above 30 °C) and tropical nights is increasing, leading to higher wildfire risk.
Precipitation trends show greater seasonal variability, with decreases in summer and increases in winter, alongside more frequent extreme precipitation events and longer dry periods.
Climate projections for higher emission scenarios (RCP8.5) foresee continued warming and a further increase in wildfire risk.
National climate datasets (ARSO and ARPA FVG) are of high quality but differ in spatial resolution and reference periods, which limits direct cross-border comparability.
For joint wildfire hazard and vulnerability analyses, globally consistent and harmonised climate data (CHELSA) were therefore also used.
