Strengthening the evidence base for urban planning in the era of climate change

Abstract

We are living in a world, in which continuous change is one of few constants. Amidst the transformations taking place, climate change, with its manifold impacts on nature and society, is undoubtedly amongst the most omnipresent ones. In the age of ongoing global urbanization, urban climate change implications, such as the urban heat island (UHI) effect, affect a major part of humanity. Thus, cities as both drivers of and sufferers from adverse conditions are a main focus of climate related research, which can be seen in a constantly growing body of relevant scientific contributions. Associated with that is the necessity of a common understanding of key concepts and definitions. However, as conceptual frameworks are not standardized and furthermore undergo thorough changes, e.g., initiated by the publication of influential IPCC (International Panel on Climate Change) reports, scientific advance is slowed down by varying perceptions, leading to not always comparable results and insights. When analyzing urban heat, there are physical and social factors to be considered. While the former ones can influence the pronunciation of heat, the latter are important to look at in terms of potentially emerging environmental (climate/thermal) injustices. Regarding heat explaining physical variables, a focus of recent research is on land use and land cover characteristics as well as landscape metrics. Urban morphology or fabric as the result of historical developments is rather rarely considered. On the social side, mostly two-sided relationships between, e.g., heat and green supply or green/heat and social status are analyzed. Here, integrated considerations are missing. The research incorporated in the dissertation at hand intends to foster the evidence base for sustainable and resilient urban planning under climate change conditions tackling the before-mentioned shortcomings. The first article featured deals with conceptual and definitional ambiguities in urban climate change research. Amongst others, a strong dominance of certain concepts (e.g., vulnerability) and a huge influence of IPCC reports could be discerned. In the second study, urban morphology and its influence on urban heat is researched for the case of Berlin. Applying a GWR (geographically weighted regression) model, the thermal performance of various urban structure types (UST) could be determined while at the same time obtaining insights on the specific effect of urban morphology parameters on heat intensity. The third article presented is dedicated to explore multi-burden areas in the Ruhr region. Besides heat, green supply as well as social factors are put in relation here via correlations and a cluster analysis. The relationship between heat and social status is found to be ambiguous depending on the city regarded. The cluster analysis could reveal areas suffering from heat, low green provision, and lower social status with a significant amount of the area's population living there (around 27%). In summary, the research featured can be seen as describing three steps necessary in order to achieve resilient cities. A common knowledge base, with common definitions and conceptual framework understandings is needed (1) before the physical urban structure has to be analyzed unleashing adaptation potentials (2). Lastly, the social aspect needs to be included in order to be able to promote tailored solutions in adaptation action benefiting the respective population (3). The outlined procedure can serve as an adaptable blueprint for further research and practice in the area while also exhibiting various connecting points.