Recent cooling enhances glacier resilience to global warming in the northern Karakoram: Evidence from tree rings

Abstract

Since the late 20th century, global warming has resulted in the significant retreat of alpine glaciers in high-altitude mountainous regions worldwide. However, the glaciers in the Karakoram Mountains of Central Asia have remained stable or even expanded over recent decades, a phenomenon termed the “Karakoram Anomaly”. Here, we use tree-ring width of Picea schrenkiana growing at high altitudes of the Karakoram Mountains, to reconstruct summer (June–August) temperature variations since 1851 (r = 0.66, n = 62, p < 0.001), and to investigate the climatic context of the “Karakoram anomaly”. Comparative analysis with nearby tree-ring studies, glacier mass balance series in Central Asia, and Northern Hemispheric temperature reconstructions reveals a significant divergence in summer temperature trends in the Karakoram Mountains after the 1980s, corresponding to anomalous glacier behavior. The combination of increased precipitation, reduced summer temperatures, and specific glacier conditions in the Karakoram region has created a unique set of natural conditions that diverge from global trends. Our findings provide further evidence supporting the existence of the “Karakoram Anomaly” under global climate change.