Ice records provide a qualitative rather than a quantitative indication of the trend of climate change. Using the bulk aerodynamic method and degree day model, this study quantified ice mass loss attributable to sublimation/evaporation (S/E) and meltwater on the basis of integrated observations (1960-2006) of glacier-related and atmospheric variables in the northeastern Tibetan Plateau. During 1961-2005, the average annual mass loss in the ice core was 95.33 +/- 20.56 mm w.e. (minimum: 78.97 mm w.e. in 1967, maximum: 146.67 mm w.e. in 2001), while the average ratio of the revised annual ice accumulation was 21.2 +/- 7.7% (minimum: 11.0% in 1992, maximum 44.8% in 2000). A quantitative formula expressing the relationship between S/E and air temperature at the monthly scale was established, which could be extended to estimation of S/E changes of other glaciers in other regions. The elevation effect on alpine precipitation determined using revised ice accumulation and instrumental data was found remarkable. This work established a method for quantitative assessment of the temporal variation in ice core mass loss, and advanced the reconstruction of long-term precipitation at high elevations. Importantly, the formula established for reconstruction of S/E from temperature time series data could be used in other regions.

During the past decades, glacier mass loss is becoming increasingly significant worldwide but knowledge about the acceleration is still limited despite its potentially profound impacts on sea level rise, water resources availability and glacial hazards. In this study, we analyzed the acceleration of glacier mass loss based on in-situ measurements and on the latest compilation dataset of direct and geodetic observations for the period 1961-2016. The results showed that the rate of glacier mass loss has increased worldwide during the past decades. At the global scale, the rate of glacier mass loss has been accelerating at 5.76 +/- 1.35 Gt a(-2) as well as 0.0074 +/- 0.0016 m w.e.a(-2) on mass balance (refer to the area-averaged mass change value) during the whole period. At regional scales, for mass change rate, the heavily glacierized regions excluding Antarctic and Subantarctic exhibited a larger acceleration compared to other regions. The highest acceleration of mass change was found in Alaska glaciers (1.33 +/- 0.47 Gt a(-2)) over the full period. As for mass balance, high acceleration occurred on the regions with small glaciers as well as on the heavily glacierized regions. Central Europe exhibited the highest acceleration (0.024 +/- 0.0088 m w.e.a(-2)) during 1961-2016. High level of consistency between the acceleration and temperature implies that climate warming had a significant effect on the accelerating of glacier mass loss. Moreover, acceleration of the contribution from the Greenland ice sheet (0.028 to 0.070 mm a(-2)) and Antarctic ice sheet (0.023 to 0.058 mm a(-2)) to sea level rise exceeds acceleration of the contribution from global glaciers (0.019 +/- 0.013 mm a(-2)). These results will improve our understanding of the glacier retreat in response to climate change and provide critical information for improving mitigation strategies for impacts that may be caused by glacier melting.

Accurate estimates of regional and global glacier mass require many field-based sample measurements that are widely distributed across an area of interest. The Sawir Mountains are an isolated mountain system in Central Asia and changes in glacier mass balance from this region have rarely been reported. In this study, we provide a comprehensive analysis of mass changes of the Muz Taw Glacier in the Sawir Mountains based on glaciological and geodetic measurements. The glaciological mass balance exhibited a strong variability during the period 2016-2020, with a range of values between - 1.29 and - 0.31 m water equivalent (w.e.) and a mean value of - 0.86 +/- 0.16 m w.e. Differences in the surface elevation of the Muz Taw Glacier were determined from analysis of a topographic map (1:100,000 scale) and terrestrial laser scanning (TLS) point-cloud data, with these data sources indicating an average surface elevation change of approximately - 33.36 +/- 9.39 m or - 0.54 +/- 0.15 m a(-1) during 1959-2021. This thickness is roughly equivalent to half of the mean thickness of the glacier terminus, which has contributed to the negative geodetic mass balance of - 28.36 +/- 8.23 m w.e. or - 0.46 +/- 0.13 m w.e. a(-1). Approximately twice as much mass has been lost from the Muz Taw Glacier during the past 5 years (2016-2020) than estimated by geodetic data, indicating that the mass loss of Muz Taw Glacier has continued unabated.

In the hydrological year 2022/2023, the glaciers in the Qilian Mountains experienced unprecedented mass loss. The glacier -wide mass balance was -1,188 mm w.e., in contrast to -350 mm of average mass balance since 1990 over the Bailanghe Glacier No. 12 in the middle of Qilian Mountains. The temperature during 2022-2023 reached the highest value ever recorded, second only to 2022, while at the same time the precipitation amount was less compared to other year since 2000, which together led to the strongest glacier mass loss during 2022-2023. The atmospheric circulation analysis shows that the high temperature in the Qilian Mountains in 2023 was jointly caused by the Arctic air mass and East Asian monsoon.

Temperature and freeze-thaw events are two key factors controlling litter decomposition in cold biomes. Predicted global warming and changes in freeze-thaw cycles therefore may directly or indirectly impact litter decomposition in those ecosystems. Here, we conducted a 2-year-long litter decomposition experiment along an elevational gradient from 3000 to 3600 m to determine the potential effects of litter quality, climate warming and freeze-thaw on the mass losses of three litter types [dragon spruce (Picea asperata Mast.), red birch (Betula albosinensis Burk.), and minjiang fir (Abies faxoniana Rehd. et Wild)]. Marked differences in mass loss were observed among the litter types and sampling dates. Decay constant (k) values of red birch were significantly higher than those of the needle litters. However, mass losses between elevations did not differ significantly for any litter type. During the winter, lost mass contributed 18.3-28.8 % of the net loss rates of the first year. Statistical analysis showed that the relationships between mass loss and litter chemistry or their ratios varied with decomposition periods. Our results indicated that short-term field incubations could overestimate the k value of litter decomposition. Considerable mass was lost from subalpine forest litters during the wintertime. Potential future warming may not affect the litter decomposition in the subalpine forest ecosystems of eastern Tibetan Plateau.