Abrupt permafrost thaw causes an exceptional increase in carbon release on the Tibetan Plateau

Climate warming on the Tibetan Plateau is accelerating the abrupt thaw of permafrost, leading to substantial carbon emissions. However, retrogressive thaw slumps (RTSs), representing the most severe instances of abrupt thaw, are poorly understood in their carbon emissions due to sparse observations. Here, by synthesizing 4,728 RTS incidents and 1,862 in-situ CO₂ and CH₄ monitoring data from the collapsed areas of RTSs on the Tibetan Plateau, we estimate that CO₂ and CH₄ release from the expansion of RTSs increased 1.3-fold from 2017 to 2022. Projections indicate that the area of RTSs susceptibility will increase 15–18% by 2100. The corresponding CO₂ release rate is projected to reach 419 ± 316 g C m⁻² yr⁻¹, roughly 1.5 times higher than the carbon uptake of alpine ecosystems on the plateau. Compared with gradual thaw, abrupt thaw will lead to a 22% increase in CO₂ release up to 2100. While the CO₂ and CH₄ release from increasing RTSs susceptibility areas will surge 1.2-fold relative to 2022. These findings suggest that abrupt thaw will enhance permafrost carbon-climate feedback in high-altitudes, highlighting the crucial need for permafrost protection strategies to achieve carbon neutrality target.