Heat stress risk and vulnerability under climate change in Durban metropolitan, South Africa-identifying urban planning priorities for adaptation

There is an urgent need to map the geographic location of climate change risks and vulnerability, especially for cities in sub-Saharan Africa, which are experiencing the greatest urban development challenges and vulnerability to climate change impacts. The aim of this study is to investigate current and projected future heat risk, expressed as a heat stress exposure index using high-resolution climate change projections, and a social vulnerability index, to identify areas of potential future heat stress risk in the Durban (eThekwini) metropolitan area, South Africa. Additionally, this is the first study to use high-resolution downscaled climate change projections under Representative Concentration (RCP) 8.5, to construct the heat exposure index using apparent temperature and increases in minimum temperature and a social vulnerability index, using demographic and socio-economic census and land use data to, derived from principal component analysis (PCA) to spatially characterize heat stress within a South African city. Results show that while heat stress is not a current concern, it is projected to increase and become a future concern, mainly as a function of social vulnerability due to household demographic and infrastructural characteristics, and will be experienced in both the rural and inner-city areas of the metro. This study contributes a heat risk framework to identify locations for specific research and adaptation activities on heat stress risk and for urban planning in sub-Saharan African cities, which are characterized by both rural and urban contexts, to address climate change adaptation targeting and priority setting.