*Article* **Quantifying the Occurrence of Multi-Hazards Due to Climate Change**

**Diamando Vlachogiannis \* , Athanasios Sfetsos , Iason Markantonis , Nadia Politi , Stelios Karozis and Nikolaos Gounaris**

> Environmental Research Laboratory (EREL), INRASTES, NCSR "Demokritos", Agia Paraskevi, 15341 Attiki, Greece; ts@ipta.demokritos.gr (A.S.); jasonm@ipta.demokritos.gr (I.M.); nadiapol@ipta.demokritos.gr (N.P.); skarozis@ipta.demokritos.gr (S.K.); gounaris@ipta.demokritos.gr (N.G.) **\*** Correspondence: mandy@ipta.demokritos.gr; Tel.: +30-210-650-3417

**Abstract:** This paper introduces a climatic multi-hazard risk assessment for Greece, as the first-ever attempt to enhance scientific knowledge for the identification and definition of hazards, a critical element of risk-informed decision making. Building on an extensively validated climate database with a very high spatial resolution (5 <sup>×</sup> 5 km<sup>2</sup> ), a detailed assessment of key climatic hazards is performed that allows for: (a) the analysis of hazard dynamics and their evolution due to climate change and (b) direct comparisons and spatial prioritization across Greece. The high geographical complexity of Greece requires that a large number of diverse hazards (heatwaves—TX, cold spells—TN, torrential rainfall—RR, snowstorms, and windstorms), need to be considered in order to correctly capture the country's susceptibility to climate extremes. The current key findings include the dominance of cold-temperature extremes in mountainous regions and warm extremes over the coasts and plains. Extreme rainfall has been observed in the eastern mainland coasts and windstorms over Crete and the Aegean and Ionian Seas. Projections of the near future reveal more warm extremes in northern areas becoming more dominant all over the country by the end of the century.

**Keywords:** climate change; multi-hazards; WRF-ARW; EC-Earth GCM; Greece
