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Studies on long-term fluctuations in glacier volume and mass are crucial for understanding past climate change. In this paper, we utilized Picea schrenkiana to develop a 525-year chronology of latewood blue intensity (LWBI) in the Tianshan Mountains. Relying on temperature as the main controlling factor for tree growth and glacier mass balance (GMB) variations, the LWBI chronology was used to reconstruct the summer temperature (JJA, R 2 adj = 47%) and the annual glacier mass balance (annual GMB, R 2 adj = 39%) in the Tianshan Mountains over the past 400 years. The reconstruction results show that the rapid warming since 1974 has caused the Tianshan No.1 glacier (TS No.1) to experience an unprecedented melting trend within the last four centuries. It is disturbing that the glacier still remain in an ablation state for the next 80 years under both representative concentration paths (RCP) 4.5 and 8.5 scenarios, which will exacerbate the adverse environmental impacts of glacial hazards. Our study provides a continuous record for glacier research in high mountains Asian and contributes to a more detailed assessment of glacier and climate change in this region. The spatial correlation analysis of the PC1 and the ERA5 grid temperature dataset after the original (a), detrended (b) and first-order difference (c) calculations in the verification period (1950–2005), all insignificant correlations (P > 0.05) were masked out, where A represent the Tianshan Mountains (this study), B represent Central Europe Alps (Büntgen et al., 2006), C represent East Asia (Davi et al., 2002), D represent Dunde ice core (Thompson et al., 2006), and E represent Guliya ice core (Thompson et al., 1997). Comparison of Tianshan temperature reconstruction (PC1) with other MXD-based temperature reconstructions, where (d) is the comparison between PC1 and Central European Alps summer (June to September) temperature reconstruction, (e) is the comparison between PC1 and East Asian Japanese warm season (May to September) temperature reconstruction, and (f) is the comparison between PC1 and Northern Hemisphere summer (June to August) temperature reconstruction (Schneider et al., 2015). (g) is the comparative between the PC1 and Atlantic multidecadal variability (AMV, Wang et al., 2017). Comparison of TS No.1 GMB reconstruction with ice core accumulation data, where (h) is the comparison between TS No.1 GMB reconstruction and Dunde ice core water equivalent net balance (accumulation, 5-year average), (i) is the comparison between TS No.1 GMB reconstruction and Guliya ice core water equivalent net balance (accumulation, 10-year average). All comparison series are Z-score normalized and low-pass filtered with a step size of 10 years (ice core accumulation data are 5 year) to achieve low-frequency fluctuations. [Display omitted] • A 525-year latewood blue intensity (LWBI) chronology was developed to study glacial dynamics for the Tianshan Mountains. • The results showed that the last 20 years to be outside the range of natural variability of the last 400 years. • The Tianshan No. 1 glacier will continue to melt rapidly in the next 80 years under the RCP 4.5 and 8.5 scenarios. [ABSTRACT FROM AUTHOR]

Mt. Everest (Qomolangma or Sagarmatha), the highest mount on Earth and located in the central Himalayas between China and Nepal, is characterized by highly concentrated glaciers and diverse landscapes, and is considered to be one of the most sensitive area to climate change. In this paper, we comprehensively synthesized the climate and environmental changes in the Mt. Everest region, including changes in air temperature, precipitation, glaciers and glacial lakes, atmospheric environment, river and lake water quality, and vegetation phenology. Historical temperature reconstruction from ice cores and tree rings revealed the distinct features of 20th century warming in the Mt. Everest region. Meteorological observations further proved that the Mt. Everest region has been experiencing significant warming (approximately 0.33 °C/decade) but relatively stable precipitation during 1961−2018 AD. Projected results (during 2006−2099 AD) under different representative concentration pathway scenarios showed a general warming trend in the region, with larger warming occurring in winter than in summer. Meanwhile, the precipitation projections varied spatially with no significant trends over the region. Intensive glacier shrinkage was characterized by decreasing glacier areas, while glacier-fed river runoff increased. Glacial lakes expanded with increasing glacial lake areas and numbers. These findings indicated a clear regional hydrological response to climate warming. Owing to the remote location of Mt. Everest, the present atmospheric environment remained relatively clean; however, long-range transport of atmospheric pollutants from South Asia and West Asia may have substantially influenced the Mt. Everest region, resulting in increasing concentrations of pollutants since the Industrial Revolution. Anthropogenic activities have been shown to influence river and lake water quality in this remote region, especially in the downstream. The end of the vegetation growing season advanced in the northern slope and did not change in southern slope region of the Mt. Everest, and there was no significant change in start date of the growing season in the region. This review will enhance our understanding of climate and environmental changes in the Mt. Everest region under global warming. • Climate and environmental changes were synthesized in the Mt. Everest region. • Glaciers have retreated significantly, posing impacts to river runoff and glacial lakes. • Transboundary transport of atmospheric pollutants influenced the region. • TThere was no significant change in start date of the growing season. [ABSTRACT FROM AUTHOR]