A meta-analysis of 253 studies reveals that ecological restoration significantly impacts greenhouse gas (GHG) emissions. Forest and grassland restoration increased methane (CH₄) uptake by 90.0% and 30.8%, respectively, due to changes in soil properties. Wetland restoration increased CH₄ emissions by 544.4%, mainly due to elevated water tables. Forest and grassland restoration had no significant effect on nitrous oxide (N₂O) emissions, while wetland restoration reduced N₂O emissions by 68.6%. Wetland restoration enhanced net CO₂ uptake, transitioning ecosystems from sources to sinks within 4 years. Forest and grassland restoration decreased global warming potentials (GWP) by 327.7%, 157.7%, and 62.0%, respectively, compared to control ecosystems. The study highlights that afforestation, reforestation, rewetting drained wetlands, and restoring degraded grasslands through grazing exclusion or converting croplands to grasslands can effectively mitigate GHG emissions. Wetland restoration significantly reduced NEE by 138.8%, while grassland restoration decreased NEE by 146.9%. Restoration age influenced GHG emissions, with wetland restoration showing exponential increases in CH₄ emissions and N₂O emissions decreasing with restoration age. Soil properties, such as soil moisture, bulk density, and redox potential, were key factors affecting GHG emissions. The study provides insights for improving IPCC guidelines and national GHG inventories, emphasizing the importance of ecological restoration in mitigating GHG emissions.A meta-analysis of 253 studies reveals that ecological restoration significantly impacts greenhouse gas (GHG) emissions. Forest and grassland restoration increased methane (CH₄) uptake by 90.0% and 30.8%, respectively, due to changes in soil properties. Wetland restoration increased CH₄ emissions by 544.4%, mainly due to elevated water tables. Forest and grassland restoration had no significant effect on nitrous oxide (N₂O) emissions, while wetland restoration reduced N₂O emissions by 68.6%. Wetland restoration enhanced net CO₂ uptake, transitioning ecosystems from sources to sinks within 4 years. Forest and grassland restoration decreased global warming potentials (GWP) by 327.7%, 157.7%, and 62.0%, respectively, compared to control ecosystems. The study highlights that afforestation, reforestation, rewetting drained wetlands, and restoring degraded grasslands through grazing exclusion or converting croplands to grasslands can effectively mitigate GHG emissions. Wetland restoration significantly reduced NEE by 138.8%, while grassland restoration decreased NEE by 146.9%. Restoration age influenced GHG emissions, with wetland restoration showing exponential increases in CH₄ emissions and N₂O emissions decreasing with restoration age. Soil properties, such as soil moisture, bulk density, and redox potential, were key factors affecting GHG emissions. The study provides insights for improving IPCC guidelines and national GHG inventories, emphasizing the importance of ecological restoration in mitigating GHG emissions.