Sensitivity of the impact of aeolian sand cover on permafrost degradation in the Qinghai–Xizang Plateau

Abstract Environmental transformations and intensifying desertification across the Qinghai–Xizang Plateau (QXP) are having a significant influence permafrost degradation, heightening the risks associated with carbon emissions, thermal hazards and infrastructural damage. However, the specific response of permafrost to desertification remains insufficiently understood. Here, we employed numerical modeling to examine the sensitivity of the impact of aeolian sand cover (ASC) on permafrost degradation. Our findings reveal that the thickness and moisture content of ASC profoundly affect permafrost degradation. Moreover, the thermal stability of permafrost and the rate of climatic warming modulate this degradation process. The simulation results identify two critical thickness thresholds for ASC: 20 cm and 80–120 cm. Specifically, dry ASC thinner than 20 cm accelerates permafrost degradation driven by desertification, whereas ASC thicker than 20 cm mitigates this effect. Furthermore, increased moisture in ASC extends the thickness threshold to 80–120 cm. These results suggest that climatic variations in the QXP, particularly transitions towards either warming–drying or warming–wetting, will markedly influence the response of permafrost to desertification. Notably, a warming–drying climate may reduce the potential degradation of permafrost caused by desertification. This study provides a critical reference for understanding the impact of aeolian desertification on permafrost in regions beyond the QXP. It holds significant policy implications for environmental conservation and infrastructure development within the plateau.