Evaluating climate change adaptation strategies and scenarios of enhanced vertical and horizontal compactness at urban scale (a case study for Berlin)

This study evaluates the effectiveness of climate change adaptation strategies in Berlin, Germany, on a summer day by using the urban climate model MUKLIMO_3. White coating, green roofs and a combination of both are analysed regarding their cooling ability on the 2 m-temperature. Additionally, horizontal and vertical compactness are evaluated in terms of their respective impact on the micro climate. An enhanced albedo of the urban surfaces leads to the highest cooling ability with a significant daily average cooling of 0.2 K per 0.1 increase of albedo, while green roofs have only a small cooling effect at pedestrian level. An increased vertical compactness has a cooling ability due to the higher amount of shading, enhanced horizontal compactness shows a negative impact on the micro climate due to the raised percentage of sealed surfaces and the additional urban structures that can emit additional heat during the night. All strategies show a higher effect on the daytime and a smaller influence on the nocturnal temperature.