The study investigates the impact of salinity on methane (CH₄) emissions from inland waters, particularly in the Canadian Prairies, a region with a high density of salt-rich ecosystems. Salinity is shown to significantly restrict CH₄ emissions through complex mechanisms, including the inhibition of methanogenesis by sulfate (SO₄²⁻) and interactions with organic matter availability. Existing models overestimated CH₄ emissions from ponds and wetlands by several orders of magnitude, and the inclusion of salinity as a variable improved model accuracy. The study found that salinity interacted with organic matter content to shape surface CH₄ partial pressure (pCH₄) in small lentic systems, leading to a significant overestimation of emissions from these systems. The findings suggest that salinity likely downregulates CH₄ emissions worldwide, and current global budgets may overestimate aquatic CH₄ emissions. The study also highlights the potential for widespread salinization of inland waters due to anthropogenic activities, which could further reduce CH₄ emissions. The implications of these findings for national and global emissions budgets are significant, emphasizing the need for accurate data and models to better understand and manage CH₄ emissions from salt-rich ecosystems.The study investigates the impact of salinity on methane (CH₄) emissions from inland waters, particularly in the Canadian Prairies, a region with a high density of salt-rich ecosystems. Salinity is shown to significantly restrict CH₄ emissions through complex mechanisms, including the inhibition of methanogenesis by sulfate (SO₄²⁻) and interactions with organic matter availability. Existing models overestimated CH₄ emissions from ponds and wetlands by several orders of magnitude, and the inclusion of salinity as a variable improved model accuracy. The study found that salinity interacted with organic matter content to shape surface CH₄ partial pressure (pCH₄) in small lentic systems, leading to a significant overestimation of emissions from these systems. The findings suggest that salinity likely downregulates CH₄ emissions worldwide, and current global budgets may overestimate aquatic CH₄ emissions. The study also highlights the potential for widespread salinization of inland waters due to anthropogenic activities, which could further reduce CH₄ emissions. The implications of these findings for national and global emissions budgets are significant, emphasizing the need for accurate data and models to better understand and manage CH₄ emissions from salt-rich ecosystems.