As climate change causes glacier retreat, mountain landscapes are undergoing irreversible transformations, creating both challenges and opportunities for biodiversity management and ecosystem services provisioning. While much attention has been given to glacier mass loss and ecological succession, less is known about the ecosystem functions and socio-economic implications of glacier retreat in newly deglaciated terrains. These emerging ecosystems provide novel habitats and functions, yet their future remains uncertain in the face of glacier extinction and competing land-use demands. Here, I present the novel concept of Plant’s Contributions to People (PCP) to assess how glacier biodiversity influences ecosystem functions and human well-being. Based on surveys of 99 plant species in four glacier environments in the Italian Alps—one of which (Trobio glacier) experienced complete extinction in 2023—we analyzed species-specific contributions to ecosystem services under present and projected future scenarios. Our findings reveal that glacier retreat drives biodiversity shifts while also altering key PCP categories, such as air quality regulation, soil health, and nutrient cycling. The greatest declines in PCP are associated with the loss of early-successional species, which initially enhance biodiversity through facilitation but later decline due to shrub encroachment and soil acidification in late successional stages. While future plant communities may provide PCP qualitatively similar to present-day ecosystems, the overall volume of contributions is expected to decrease with the loss of pioneer species. These results highlight the need for forward-looking conservation strategies that integrate ecological, social, and economic dimensions of biodiversity change. By combining long-term biodiversity monitoring with inclusive, future-oriented narratives, we can guide the sustainable development of emerging post-glacial landscapes, ensuring these novel ecosystems are not merely seen as remnants of loss but as opportunities for sustainable transformation. Collaborative management approaches will be crucial for securing biodiversity, ecosystem services, and socio-ecological resilience in high-altitude, post-glacial environments.