Uneven resilience: Constructing a climate environmental vulnerability index for South Africa's urban core

Urban areas in developing countries are increasingly exposed to climate risks, yet vulnerability assessments often remain generalised and fail to capture intra-regional disparities. This study addresses this gap by developing a Climate Environmental Vulnerability Index (CEVI) for municipalities in Gauteng Province, South Africa, over the period 2010–2024. The CEVI integrates 17 standardised indicators across three dimensions: exposure, sensitivity, and adaptive capacity, using Principal Component Analysis (PCA) to construct sub-indices and a composite vulnerability measure. The results reveal significant spatial and temporal variation in climate vulnerability across municipalities, highlighting the multidimensional and uneven distribution of risk across geographically proximate areas. While some municipalities exhibit persistently high vulnerability due to limited adaptive capacity, others demonstrate relative resilience despite similar levels of climatic exposure. The findings show that differences in adaptive capacity are the primary drivers of variation in vulnerability across municipalities, with improvements in socio-economic conditions playing a more decisive role than exposure alone. These results underscore the importance of spatially differentiated and multidimensional approaches to climate risk assessment. From a policy perspective, the study highlights the need for targeted, municipality-level adaptation strategies rather than uniform provincial interventions. The CEVI framework provides a practical and replicable tool for urban planners and policymakers to support evidence-based resource allocation and enhance climate resilience in rapidly urbanising regions, thereby enabling more targeted and effective urban climate adaptation policies.