Recent climate change has caused an increase in warming-driven erosion and sediment transport processes on the Tibetan Plateau (TP). Yet a lack of measurements hinders our understanding of basin-scale sediment dynamics and associated spatiotemporal changes. Here, using satellite-based estimates of suspended sediment, we reconstruct the quantitative history and patterns of erosion and sediment transport in major headwater basins from 1986 to 2021. Out of 13 warming-affected headwater regions, 63% of the rivers have experienced significant increases in sediment flux. Despite such intensified erosion, we find that 30% of the total suspended sediment flux has been temporarily deposited within rivers. Our findings reveal a pronounced spatiotemporal heterogeneity within and across basins. The recurrent fluctuations in erosion-deposition patterns within river channels not only result in the underestimation of erosion magnitude but also drive continuous transformations in valley morphology, thereby endangering local ecosystems, landscape stability, and infrastructure project safety.

The Qinghai‐Tibetan Plateau (QTP) has undergone significant warming, wetting, and greening (WWG) over decades, alongside substantial alterations in hydrological regimes. These changes present great challenges for safeguarding water resources and ecosystems downstream. However, the lack of field observation and systematic research has obscured our understanding of how hydrological processes respond to the combined influences of climate‐permafrost‐vegetation. This study focuses on the source regions of the Yangtze River, one of the highest permafrost‐covered basins on the QTP, and employs a process‐based hydrological model to quantify the effects of WWG on hydrological processes. We show that the increasing precipitation dominates subsurface runoff changes while rising temperature primarily affects surface runoff changes by reducing the frozen duration (−52 days/century) and thickening the active layer (+2.4 cm/year). Greening vegetation primarily affects transpiration and interception evaporation. Warming, wetting, and greening will cause a transition in runoff dynamics from surface runoff dominance to subsurface runoff dominance in permafrost basins, and reduce the risk of both flooding and water shortage indicated by the decreased maximum low flow duration and maximum high flow duration of 11.0 and 5.0 days/year, respectively. Moreover, cold permafrost regions exhibit a greater propensity for generating runoff, as indicated by a higher annual increase in runoff coefficient (0.005/year) and total runoff (4.81 mm/year), compared to warm permafrost regions (with increase of 0.001/year and 1.20 mm/year, respectively). These findings enhance the understanding of hydrological changes due to WWG and provide insights for water resources management in permafrost regions under climate change.

Climate-sensitive northern cryosphere inland waters emit greenhouse gases (GHGs) into the atmosphere, yet their total emissions remain poorly constrained. We present a data-driven synthesis of GHG emissions from northern cryosphere inland waters considering water body types, cryosphere zones, and seasonality. We find that annual GHG emissions are dominated by carbon dioxide ( 1149.2 1004.8 1307.5 teragrams of CO ₂ ; median Q 1 Q 3 ) and methane ( 14.2 10.1 18.5 teragrams of CH ₄ ), while the nitrous oxide emission ( 5.4 − 1.4 12.2 gigagrams of N ₂ O) is minor. The annual CO ₂ –equivalent (CO ₂ e) GHG emissions from northern cryosphere inland waters total 1.5 1.3 1.8 or 2.3 1.8 2.8 petagrams of CO ₂ e using the 100- or 20-year global warming potentials, respectively. Rivers emit 64% more CO ₂ e GHGs than lakes, despite having only one-fifth of their surface area. The continuous permafrost zone contributed half of the inland water GHG emissions. Annual CO ₂ e emissions from northern cryosphere inland waters exceed the region’s terrestrial net ecosystem exchange, highlighting the important role of inland waters in the cryospheric land-aquatic continuum under a warming climate.

Global warming causes permafrost thawing, transferring large amounts of soil carbon into rivers, which inevitably accelerates riverine CO₂ release. However, temporally and spatially explicit variations of riverine CO₂ emissions remain unclear, limiting the assessment of land carbon-climate feedback. Using new and published 5685 riverine CO₂ partial pressure data in the Arctic and Tibetan Plateau, we show that current riverine CO₂ emission across the Northern Hemisphere permafrost zone is 200 ± 15 Tg C yr⁻¹. The emission offsets 28.1 ± 2.1% of the land carbon uptake in the Northern Hemisphere permafrost zone, with large regional variability of 13.1 to 63.1%. Our findings suggest that CO₂ emissions increased at a rate of 0.42 ± 0.16 Tg C yr⁻¹ during 2000 to 2020, and this is primarily driven by increased precipitation and accelerated permafrost thawing under climate change. This study highlights increased riverine carbon emission and strengthening of the permafrost carbon feedback to climate after incorporating carbon release from rivers.

Thermokarst lakes, serving as significant sources of methane (CH₄), play a crucial role in affecting the feedback of permafrost carbon cycle to global warming. However, accurately assessing CH₄ emissions from these lakes remains challenging due to limited observations during lake ice melting periods. In this study, by integrating field surveys with machine learning modeling, we offer a comprehensive assessment of present and future CH₄ emissions from thermokarst lakes on the Tibetan Plateau. Our results reveal that the previously underestimated CH₄ release from lake ice bubble and water storage during ice melting periods is 11.2 ± 1.6 Gg C of CH₄, accounting for 17 ± 4% of the annual total release from lakes. Despite thermokarst lakes cover only 0.2% of the permafrost area, they annually emit 65.5 ± 10.0 Gg C of CH₄, which offsets 6.4% of the net carbon sink in alpine grasslands on the plateau. Considering the loss of lake ice, the expansion of thermokarst lakes is projected to lead to 1.1–1.2 folds increase in CH₄ emissions by 2100. Our study allows foreseeing future CH₄ emissions from the rapid expanding thermokarst lakes and sheds new lights on processes controlling the carbon-climate feedback in alpine permafrost ecosystems.