Climate change and its impacts on glaciers and glacial lakes in Nepal Himalayas

Abstract

Nepal, a Himalayan country, is often chosen by global scientists to study climate change and its impact on the Himalayan environment. The changes in temperature, precipitation, glaciers, and glacial lakes over Nepal are comprehensively reviewed based on published literature and compared with regional studies. Furthermore, the published glacier datasets were used to calculate and analyze the changes in area, equilibrium line of altitude (ELA) and ice reserves to show the response of glaciers to climate change. We find that the warming trend (0.02 to 0.16 °C yr−1) is being more pronounced over Nepal, and heterogeneous changes in precipitation amount, pattern, and frequency are observed with no significant trend. Concurrently, the glaciers are found to be responding with heterogeneous shrinkage in area (− 1 to − 5 km2 yr−1), possessing negative mass balance (− 0.3 to − 0.8 m w.e. yr−1), decrease in ice volume (− 4.29 km3 yr−1) and upward shift of the ELA (~ 20.66 m decade−1). The total decrease in ice reserve (− 128.84 km3) of Nepal has resulted in ~ 0.32 mm of sea level rise in past 30 years. Moreover, the formation and surface area expansion (0.83 % yr−1) of glacial lakes over Nepal have been accelerated. Additionally, we note that Nepal is highly susceptible to glacial lake outburst flood (GLOF) events and document a total of 45 reliable reported and unreported historical GLOF events from 39 glacial lakes across Nepal. This review will facilitate a comprehensive understanding of the current state of climate change and the identification of existing knowledge gaps in Nepal.

Glacial Lake Changes and Risk Assessment in Rongxer Watershed of China–Nepal Economic Corridor

“…Global warming plays a prominent role in the rapid expansion of glacial lakes and the increasing risk of GLOF. The retreat of glaciers has been caused by increased temperatures and decreased precipitation [4,27,59,60], exacerbating interactions between glaciers and lakes. This interaction leads to more ice mass loss, which ultimately results in the expansion of glacial lakes [61,62].…”

“…As one of the shortest pathways to Nepal's capital, Kathmandu (166 km), the Rongxer Watershed is a crucial trade route between China and Nepal [26]. The Rongxer Watershed's landscape is characterized by rugged, high-mountain terrain and deep valleys, accompanied by a warm, humid climate and ample precipitation [27,28]. Its topography varies from elevated areas in the north to lower terrain in the south, showcasing numerous peaks surpassing 5000 m, with the highest point reaching an elevation of 7310 m [29].…”

Timing, Causes, and Ecological Impacts of the 1991 Glacial Lake Outburst Flood at Rijieco in the Eastern Himalayas

“…Worldwide, including the Himalayas, glaciers are rapidly melting in the context of changing climatic conditions and are leading to the growth of glacial lakes (Khadka et al, 2023;Nie et al, 2017;Shugar et al, 2020). The long-term climatic data from Pali meteorological station shows an increasing temperature trend of 0.017 °C per decade (Fig.…”

Glacial Lakes of Mongolia

“…Glacial lakes act as sediment traps that store climate signals. They are sensitive indicators for regional climate change, as they are directly linked to the climate-controlled melting processes of their associated glaciers [1][2][3][4]. The annual cycle of sedimentation is characterized by the seasons: while sediment influx is increased during the melting season in spring and summer, it stagnates during the winter.…”