Climate change and overheating: A multi-level risk assessment of impacts on Greek cities

Climate change and overheating pose significant risks and challenges for humans, for theenvironment, and for contemporary cities. Among its consequences, urban overheating,extreme weather events and heatwaves very often affect human life at various levels,developing several societal, economic, and natural hazards. The Mediterranean region is one ofthe most exposed to climate change risks areas in the world, due to its specific climate andgeographic characteristics in combination with the existing socio-economic gaps, populationgrowth and migration levels. Countries and cities located around the Mediterranean areasuffered from increased temperatures and heatwaves several times in recent years. Indicatively,Cooling Degree Days -an indicator expressing the demand for space cooling due to increasedweather temperatures- have increased by around 57% since 1979 in Greece, according toofficial statistics. Following the need to address these challenges, this study aims to identify andevaluate the impacts and risks of overheating in the context of climate change in Greek cities. Ituses the method of Operational Risk Management in three steps. Firstly, it investigates thehazards and risks of climate change through extended research in the recent literature,classifying them to risks for humans (health, employment), environment (disaster ofecosystems) and cities (building environment, economy, society). Secondly, the assessment ofthe identified hazards is implemented through the evaluation done by different city stakeholdersinvolved in urban activities (public entities, research and academy, private sector, non-governmental organizations, citizens). The results from the stakeholders are used at a laterstage for calculations, leading to a ranking of the hazards by importance/severity and byprobability of happening soon. The findings could shed light on the most vulnerable aspects ofthe cities affected by climate change. This evaluation and the resulted ranking could be also animportant finding for policymakers to design and implement Disaster Risk Reduction (DRR) andclimate adaptation policies.Keywords: climate change; heatwaves; Operational Risk Management; hazards severity