Water resource vulnerabilities from climate-induced tipping point behaviour in runoff volumes and seasonality in the region of the ‘Karakoram Anomaly’: A snow-glacier melt perspective

Hunza River Basin, Karakoram range, Pakistan Assessing the future persistence of the 'Karakoram Anomaly,' under climate change scenarios, where glaciers in the region exhibit stable or slightly negative mass balances, contrary to global trends. The study explores how long the anomalous behaviour in Karakoram glaciers will persist under future climate scenarios. The results indicate a significant temperature rise under Shared Socioeconomic Pathway 5 (SSP5), whereas SSP2 exhibits greater variability. Snow Water Equivalent (SWE) is projected to decline due to reduced snowfall and faster snowmelt across all seasons, particularly in summer and autumn. Our glacio-hydrological model projects substantial glacier retreat from 4270 km 2 in 2010 reducing to 3540 km 2 or 2730 km 2 by 2100 according to SSP2 and SSP5, respectively. Increased annual runoff peaks around 2050 (SSP2) and by 2070 (SSP5) before decline in total runoff by 2100. The study also highlights significant climate change impacts on seasonal hydrology, associated with declines in glacier and snowpack water storage in the next three decades. This stresses the need for adaptive water resource management (e.g. storage infrastructure or changing demand management) to address potential water shortages to human water users e.g. irrigation and hydropower and associated ecosystem disruptions including extreme flooding. These findings provide valuable insights for future hydro-climatic dynamics and policymaking in the region. • Future persistence of Karakoram Anomaly using glacio-hydrological model. • Higher winter and less summer precipitation with reduced SWE is predicted. • Significant glacier retreat, with annual runoff peaking around 2050 (SSP2) and 2070 (SSP5).