Divergent glacier area and elevation changes across the Tibetan Plateau in the early 21st century

Abstract

With accelerated warming, mountain glaciers in most parts of the world have been in a state of continuous retreat in recent decades. Assessing glacier change and analyzing its influencing factors are essential for developing climate change mitigation and adaptation measures for a given region. This study provides a spatially explicit assessment and quantification of glacier changes in the early 21st century on the Tibetan Plateau (TP) at individual glacier and basin scales. We established a one-to-one correspondence between the Second Chinese Glacier Inventory (CGI-2, collected from 2004 to 2011) and a dataset of glacier inventory in Western China during 2017–2018 (CGI-2018). The majority of TP’s glaciers decreased in size with a mean area retreat rate during the investigated period of 4.1%/decade. In addition, a mean change of the median elevation of the glaciers of 6.7 m/decade was detected. Approximately 2.5% of the total number of glaciers mapped in CGI-2 disappeared, while 681 of them divided to 1758 glaciers as they retreated. The observed variations follow local trends and have different regional characteristics. Generally, the glaciers with the lowest retreat rates are found in the Karakorum and Kunlun Mountains, while those with high retreat rates are concentrated along the Gangdis and Tangula ranges. The observed changes in glaciers are mainly attributed to a significant increase in temperature. Other factors including glacier size, debris cover, orientation and mean elevation also contribute to the heterogeneity of glacier variability. This study provides for the first time a detailed spatially explicit analysis of the glacial changes on the TP in the early 21st century, substantially improving the understanding of glacier response patterns and supporting more sustainable utilization of regional water resources in the TP in the context of climate warming in the 21st century.