South Africa (SA) is projected to become warmer and drier, with increasing frequency and intensity of extreme climatological and hydrometeorological events. The changing climate affects the agri-food systems, compounds water insecurity, and impacts socio-economic and environmental systems. This study analyses climate risks on water and agri-food systems in three provinces, representing three Hydro-Climatic Zones (HCZs) of SA. The study used the Climate Moisture Index (CMI) to assess water stress and the Thermal Heat Index (THI) to identify heat stress across different HCZs and time periods. Past and projected rainfall and air temperatures, described as historical (1960–1990), present (2015–2044), and distant future (2070–2099) time horizons, were used to compute the CMI and THI. More severe changes in the CMI and THI, indicative of drier, hotter climates, are observed in HCZ 1. The results indicate a heterogeneous decrease in rainfall across the study sites alongside distinct increases in temperatures. These conditions indicate an increasing likelihood of water and heat stress, which will exceed the optimal thresholds for crops. Understanding the severity of climate risks is critical to mitigating their impact on socio-ecological and agri-food systems. The study’s results highlight the need for context-specific, transformative adaptive strategies. Simplifying crop stress indices and prioritising the adoption of crops with high thresholds to water and heat stress will support sustainable natural resource management and strengthen the resilience of agri-food systems, particularly in marginalised environments.
Ndlovu et al. (Fri,) studied this question.