Assessing biodiversity responses to climate change in South Africa using National Living Planet Index

South Africa’s biodiversity is increasingly threatened by climate change, yet system-specific impacts across terrestrial, freshwater, and marine ecosystems remain under-quantified. This study examined whether rising surface air temperatures are statistically associated with vertebrate population trends, using a reweighted National Living Planet Index (LPI) to represent ecological change. The study aimed to test temperature–biodiversity relationships across the three ecological systems to inform alignment with the National Biodiversity Strategy and Action Plan (NBSAP) and the National Climate Change Adaptation Strategy (NCCAS). A positivist paradigm informed a quantitative correlational design. Secondary temperature data were drawn from the World Bank Climate Knowledge Portal, while biodiversity data came from the Zoological Society of London’s LPI database. Analyses included descriptive statistics, Shapiro–Wilk tests, Pearson correlations, Mann–Kendall trend analysis, and outlier screening through box-and-whisker plots. Results indicated a significant upward temperature trend (Z = 5.92, p < .001). Freshwater biodiversity correlated positively with temperature (r = .747, p < .001), suggesting potential resilience or adaptive responses. Marine biodiversity correlated negatively (r = –.580, p < .001), indicating heightened vulnerability to thermal stress. Terrestrial biodiversity showed no significant association (r = –.130, p = .364), implying stronger influence from non-climatic drivers such as land-use change. Recommendations include ecosystem-specific adaptation, urgent marine interventions, strengthened freshwater governance and monitoring, and improved terrestrial habitat connectivity, alongside integrating biodiversity indicators into climate adaptation policy.