Changes to land use carbon emissions (LUCEs) have become significant contributors to increasingly severe climate issues. Land use change is one of the crucial factors that affect carbon emissions. Alpine meadows regions are sensitive to climate change and human activities. However, current research on LUCEs mainly focuses on analyzing present land use status and spatial patterns. To reveal and forecast future LUCEs in the alpine region, the Upper Yellow River of Gannan (UYRG) was used as a case study. Based on the land use data from 1990 to 2020, we used the multi-scenario PLUS model to predict the land use types in 2030 and analyzed the spatial and temporal dynamic trends of LUCEs from 1990 to 2030. The results showed a strong correlation between the predicted and actual land use types, with a Kappa value of 0.93, indicating the applicability of the PLUS model in predicting land use in the UYRG. Over the study period, construction land expanded, while woodland and grassland diminished. Carbon emissions (CEs) increased by 516.4% from −200,541.43 Mg CO₂e in 1990 to 835,054.08 Mg CO₂e in 2020, with construction land being the main contributor. In the Natural Development scenario for 2030, construction land expanded most rapidly, resulting in the highest LUCEs. In the Ecological Protection scenario, woodland and grassland expanded, while construction land decreased, leading to an expansion in carbon sinks. In the Cropland Protection scenario, cropland expanded, with CEs falling between the other two scenarios. These findings lay a theoretical groundwork for formulating policies addressing LUCEs in alpine meadows, providing valuable insights for further studies.