Increased global warming potential during freeze-thaw cycle is primarily due to the contribution of N₂O rather than...

While freeze-thaw cycle (FTC) can influence greenhouse gas emissions, the specific greenhouse gas that responds most strongly to FTC, as well as the underlying mechanisms, remain unclear. Here, we conducted a meta-analysis to explore the responses of global warming potential (GWP) and the fluxes of CO₂ and N₂O to FTC. Our results showed that FTC treatment significantly increased GWP, N₂O flux, cumulative GWP, and cumulative N₂O emissions by 23.1 %, 53.2 %, 14.5 %, and 164.6 %, respectively, but did not affect CO₂ flux, indicating that the enhanced GWP during the FTC period may be primarily due to the contribution of N₂O flux rather than CO₂ flux. The responses of GWP (+68.6 %), CO₂ (+21.0 %), and N₂O fluxes (+136.3 %) in croplands was higher than those in other ecosystems, exhibiting a strong dependence on ecosystem types. The effect size of FTC treatment on greenhouse gas emissions escalated with decreasing freezing temperature and diminished with increasing FTC frequency. Moreover, mean annual temperature (MAT) and FTC patterns were key factors influencing GWP during the FTC period. These findings provide critical insights into the variations in greenhouse gas emissions due to FTC and its influencing factors, allowing for more accurate predictions of the future impact of global climate change on GWP.