Asymmetric climatic responses to permanent glacier and snow cover reduction over the Tibetan Plateau

Global warming has driven a marked reduction in permanent glacier and snow cover over the Tibetan Plateau (TP), yet how this loss quantitatively and mechanistically feeds back onto regional climate remains poorly understood. The influence of permanent glacier and snow cover (PGSC) reduction on the climate of the TP was investigated using the Weather Research and Forecasting (WRF) model through comparative scenario analysis, revealing pronounced regulatory effects. The precipitation regime underwent substantial reconfiguration relative to the modest regional warming of only 0.01 °C. Surface energy changes caused by the weakening of the regional cold source altered atmospheric circulation, increasing annual precipitation by 2.6% across the TP and by 6.8% within the reduction zone. Furthermore, extreme precipitation in the south trended towards greater intensity (PRCPTOT: +20.78 mm), duration (CWD: +0.19 d) and frequency (CWD frequency: +0.2 eventsper year). In contrast, the regional temperature response was modest, though a suppression of cold extremes (TNn: +0.03 °C) was observed. These findings highlight the critical importance of incorporating PGSC reduction and its associated climate feedbacks into assessments of TP function and regional climate security under ongoing global warming.