Global glacier albedo trends over 2000–2022: Drivers and implications

Despite the accelerated loss of global glacier mass in the 21st century, the dynamics governing glacier albedo and its role in this decline are not fully understood. Addressing this knowledge gap, this study investigates global glacier albedo trends, a critical but overlooked factor in the context of climate change. this investigation utilized the Randolph Glacier Inventory v7.0, Moderate Resolution Imaging Spectroradiometer (MODIS) imagery, and ERA5-Land reanalysis data to decode the trends and drivers of glacier albedo from 2000 to 2022 on a global scale. We reported a general global albedo decline of 0.06% ± 0.04% (at 95% confidence level) per annum with regional deviations, predominantly driven by increases in surface air temperature across most regions, challenging the conclusions of earlier regional studies. Notably, in the Low Latitudes and South Asia East (SAE), as well as Antarctic and Subantarctic (AS) regions, aerosols (31% for SAE and 37% for AS) emerged as significant albedo influencers. Other factors, such as snowline migration, debris cover, glacier algae growth, and dust accumulation, are also known to influence glacier albedo but were not explicitly modeled in this study. These findings underscore the criticality of bespoke climate adaptation strategies, particularly addressing aerosol impacts, and reinforce the urgent need for a cohesive, global approach to glacier darkening and melt mitigation and protection.