The effect of climate change and urbanization on outdoor microclimate: A case study in Berlin

The urban overheating phenomenon is becoming significant in cities, causing extreme weather conditions that negatively affect citizen comfort and health, and increase building energy consumption. This research, in line with the objective of reducing overheating in city centers, investigates a Berlin district, in Germany, which has undertaken consistent urban evolutions during the last few years. The area falls into the Mitte, Tiergarten, and Moabit quarters and is the site of several governmental and institutional buildings, which were mainly built after 2000. Through a numerical approach, the microclimatic conditions are studied, during a representative summer day, at 3 different times: a past time (2000) before the construction of the main government buildings, a current time (2022), and a future time (2035) taking into account the new building constructions already planned for that area. The urban simulations are performed in ENVI-met, employing, for the past and current climate, weather data registered from the nearest weather station, and for the future one, provisional weather conditions developed according to the RCP 4.5 as 50% warming scenario, and RCP 8.5 as a 95% most warming scenario. Finally, by investigating 7 scenarios, the study shows the weight of climate change and of urbanization on the variation in microclimatic conditions in the considered area of Berlin.