Climate (In-) Justice in German Cities? Assessing the Relationship between Land Surface Temperature and Affordability of Housing

Abstract

Two megatrends cumulate and interact in urban areas: global warming and urbanization. Their combination leads to growing numbers of urbanites affected by negative health impacts. Considering US cities, strong correlations between social indicators like income or race and areas featuring pronounced urban heat island intensities (UHII) are detected. This paper’s objective is to research whether correlations also exist in German cities. The chosen approach relates the affordability of housing (apartment rent as proxy) and land surface temperature (LST) in the seven largest German cities. Results yield no significant correlations between rent levels and LST. Thus, based on the methodology applied and the data used, there is no proof of climate injustice regarding heat hazard and the exposure of different socio-economic groups. One reason might lie in typical German urban morphological structures, e.g., perimeter block development and large housing estates. While high densities, centrality, and fewer urban green characterize the former typology, it is often found in sought-after residential areas and thus relatively hot and costly. The latter consists of large, sparsely distributed structures with vegetation patches in-between, making the surroundings cooler while apartments are often cheaper. The results obtained provide valuable information for planners, real estate development and social politics.