The study highlights the significant role of inland freshwater ecosystems in the global carbon cycle, which has been underestimated due to their small surface area. By integrating data on gas exchange, sediment accumulation, and carbon transport, the research estimates that inland waters receive approximately 1.9 Pg C yr⁻¹ from terrestrial sources, with 0.2 Pg C yr⁻¹ buried in sediments and 0.8 Pg C yr⁻¹ returned to the atmosphere. The remaining 0.9 Pg C yr⁻¹ is delivered to the oceans. These findings suggest that inland waters are not passive conduits but active components of the carbon cycle, storing carbon in sediments and emitting CO₂ to the atmosphere. The study also emphasizes the importance of considering inland waters in regional and global carbon budgets, as they contribute significantly to carbon fluxes. The research underscores the need for further investigation into the role of inland aquatic systems, particularly in understanding the impacts of human activities and climate change on the carbon cycle. The study provides a comprehensive overview of the carbon dynamics in inland waters, highlighting their critical role in the global carbon budget.The study highlights the significant role of inland freshwater ecosystems in the global carbon cycle, which has been underestimated due to their small surface area. By integrating data on gas exchange, sediment accumulation, and carbon transport, the research estimates that inland waters receive approximately 1.9 Pg C yr⁻¹ from terrestrial sources, with 0.2 Pg C yr⁻¹ buried in sediments and 0.8 Pg C yr⁻¹ returned to the atmosphere. The remaining 0.9 Pg C yr⁻¹ is delivered to the oceans. These findings suggest that inland waters are not passive conduits but active components of the carbon cycle, storing carbon in sediments and emitting CO₂ to the atmosphere. The study also emphasizes the importance of considering inland waters in regional and global carbon budgets, as they contribute significantly to carbon fluxes. The research underscores the need for further investigation into the role of inland aquatic systems, particularly in understanding the impacts of human activities and climate change on the carbon cycle. The study provides a comprehensive overview of the carbon dynamics in inland waters, highlighting their critical role in the global carbon budget.