This study assessed the spatial and temporal dynamics of carbon sequestration in the Southern Guinea Savannah agro-ecological zone of Taraba State, Nigeria, between 1987 and 2024. Multi-date Landsat imagery was classified into land use and land cover categories, and aboveground biomass was estimated and converted to carbon using the Intergovernmental Panel on Climate Change (IPCC) default factor of 0.5. The results revealed significant fluctuations in carbon storage across the study period. Carbon stocks increased between 2004 and 2014, reflecting localized vegetation recovery and temporary gains in biomass. However, this growth was unsustained, as carbon sequestration declined sharply between 2014 and 2024, reverting to levels comparable with 2004. The trajectory highlights the strong influence of deforestation, agricultural expansion, and land degradation, compounded by climatic variability. Statistical analysis confirmed significant differences in carbon sequestration across years, with the most substantial decline occurring between 2014 and 2024. The findings underscore the vulnerability of the Guinea Savannah’s carbon sink capacity and its susceptibility to unsustainable land use practices. The study recommends sustainable forest management, afforestation and reforestation, community-based conservation, and climate-smart agriculture to safeguard carbon stocks. These measures are critical for enhancing ecosystem resilience and contributing to Nigeria’s climate mitigation and adaptation goals.