Climate Change Reshaping the Water Cycle in Arid Central Asia

Global climate change is reshaping the hydrological regimes in arid Central Asia, where water resources depend heavily on glacier melt, snowmelt, and rainfall. Compared with well-studied high-mountain regions such as the Himalaya and the Alps, hydrological responses in Central Asia remain insufficiently synthesized. This review summarizes recent advances in climate change, moisture transport, glacier and snow dynamics, runoff changes, and related risks under continued warming. During 1960–2024, air temperature rose by ~0.33 °C per decade, while precipitation increased modestly by ~2.3 mm per decade. Westerly moisture dominates Central Asian precipitation but weakens southward, while recent low-latitude moisture contributions have increased in the southern part, especially the southern Tarim Basin. Persistent warming has driven widespread glacier retreat across Central Asia, with regional mass losses of −0.095 to −0.135 m w.e. a−1 during 2000–2016/2018/2019, and even the previously stable Kunlun and Pamir glaciers now showing signs of retreat. Snow-covered area and duration have generally declined, and in the Naryn River Basin, peak snow water equivalent during 2077–2096 is projected to decrease by ~17% relative to 1981–2000 under SSP5-8.5. Runoff has generally increased in the Tianshan (0.50–6.12 mm/a) and Kunlun Mountains (0.06–0.72 mm/a), whereas the Pamir–Alay region shows spatially heterogeneous changes (−5.02–1.78 mm/a), with both increasing and decreasing trends. Future runoff in Central Asia will likely increase in mountainous headwaters during the early to mid-21st century, but become increasingly heterogeneous and seasonally redistributed as glacier storage declines. Future research should strengthen high-mountain observations, cross-border data sharing and multi-source data assimilation to better constrain water availability and support climate change adaptation.