Warming erodes climate connectivity for terrestrial vertebrates

Although climate-driven connectivity plays a critical role in linking discrete habitats, it remains unclear whether it can continue to support the migration and adaptation of terrestrial vertebrates under global warming. Here, we develop a metric to consider this connectivity (functional effectiveness of climate connectivity: FECC), which quantifies the contribution of climate corridors in linking suitable areas for specific biological communities. We show that with warming exceeding 4°C, approximately 77.9% of the global land area is projected to experience a decline in FECC during 2061–2080, greatly restricting the range of suitable areas accessible to species. As warming intensifies, disruptions to climate connectivity are expected to increasingly undermine the integrity of habitat networks, raising the risk of ecological isolation and local biodiversity loss. Our findings highlight regions most vulnerable to the erosion of climate connectivity, providing guidance for aligning conservation priorities and adaptive management.