Assessing glacier changes and hydrological impacts in the upper Indus Basin under CMIP6 climate scenarios

Glaciers in the Himalaya are vital for sustaining streamflow in the Upper Indus Basin. This study quantifies future glacier mass and area changes in the Jhelum sub-basin using projections from 13 bias-corrected CMIP6 climate models under SSP245 and SSP585 scenarios. A temperature-index melt model, combined with field-validated glacier thickness, outlines, and mass balance data, is used to simulate glacier response to climate forcing. Results indicate glacier area losses of 34.7 ± 12.1% under SSP245 and 55.3 ± 16.1% under SSP585 by the 2080s, accompanied by a significant decline in glacier streamflow. These projected changes threaten water availability in the region, with serious implications for agriculture, hydropower, and regional water security. By integrating multiple data sources and modeling approaches, the study provides robust estimates of glacier change and highlights the need to incorporate glacier dynamics into long-term climate adaptation and water resource planning in the Upper Indus Basin.