Surface albedo decreases from anthropogenic impacts over High Mountain Asia with implications of positive radiative forcing feedbacks

Abstract Human and climate induced land surface changes resulting from irrigation, snow cover decreases, and greening impact the radiative forcing by changing the surface albedo. Here we use a partial information decomposition approach and remote sensing data to quantify the effects of the changes in leaf area index, soil moisture, and snow cover on the surface albedo in High Mountain Asia (HMA), home to over a billion people, from 2003 to 2020. The study establishes strong evidence of anthropogenic agricultural water use over irrigated lands (e.g., Ganges-Brahmaputra) which causes the highest surface albedo decreases (£1%/year). Greening and decreased snow cover from warming also drive changes in visible and near-infrared surface albedo in different areas of HMA. The significant role of human management and human-induced greening in influencing albedo suggests the potential of a positive feedback cycle where albedo decreases lead to increased evaporative demand and increased stress on water resources.