Downscaling di scenari climatici futuri in orografia complessa, per comunità e portatori di interesse residenti in Alta Carnia

This thesis presents the main results of the doctoral project funded by the Italian Agenzia per la Coesione Territoriale, Dipartimento per le Politiche di Coesione e per il Sud, in collaboration with the University of Trieste (CUP E59J21007730005). Its main objectives are: 1. to study future climate projections over Alta Carnia; 2. prepare and deliver future climate data and information - tailored to the complex orography of this alpine territory - to local communities and stakeholders, with the mediation of the Comunità di Montagna della Carnia; 3. to raise awareness of the scientific basis and consequences of climate change among residents and young inhabitants of Alta Carnia, through dedicated workshops and dissemination initiatives. Given the paramount importance of near-surface temperature (TAS) for human life, health, ecosystems and agriculture, this thesis explores future climate projections and downscaling procedures of mean monthly TAS and tests a promising and acknowledged method to generate quantitative information at the local scales. Regarding the thesis structure, it consists of: a first part, that draws the larger picture of anthropogenic climate change, at the global scale and in the Alps; a second introductory part, that addresses the modelling of climate, clarifies the specificities of future climate projections and reviews the main characteristics of downscaling and bias-correction approaches. These two parts set the necessary theoretical background. Next, the data employed, both measurements and model simulations, are described. The results section connects the core findings of the research: 1. projections of future TAS anomalies and the associated end-of-century climate change signal, under different global emission scenarios and for a rich ensemble of EURO-CORDEX models; 2. projections of the shift in the freezing level altitude (snowline) at the Mt. Zoncolan ski resort; 3. analysis of the sources of the regional climate models TAS biases and quantification of each bias component, based on the type of weather station and the atmospheric boundary layer that it represents. The final part of the results section assesses the performance of empirical quantile mapping to downscale mean monthly TAS. A dedicated chapter of the thesis outlines the key phases of the engagement with local stakeholders and public institutions, as well as the scientific dissemination activities undertaken, providing an overview of their context, contents, format and outcomes. The conclusions offer a synthesis and a reflection on the main findings and outline possible future research directions inspired by this work, aimed at both improving the results achieved and extending the approach to encompass other territories and additional climatic indices, relevant to local stakeholder needs and the design of local adaptation strategies.