Context: According to a report published by the Intergovernmental Panel on Climate Change (IPCC),  glaciers in the Hindu Kush Himalayan region will keep shrinking as extreme precipitation is projected to increase in major mountainous regions.
Background

• A 2019 IPCC report on oceans and the cryosphere in a changing climate had revealed that the HKH region, an area covering high mountain chains of central, south and inner Asia, faces the risk of losing over 60 per cent of its glaciers by 2100.
• The region includes mountain ranges of the Tien Shan, Kun Lun, Pamir, Hindu Kush, Karakoram, Himalayas, and Hengduan and the high-altitude Tibetan Plateau and it produces one of the world''s largest renewable supplies of freshwater.
• It supports a population of 12 crore directly through irrigation systems and 130 crore people indirectly through the river basins in India, China, Nepal, Pakistan, Bangladesh and Afghanistan.

Key findings of IPCC report

• According to the report, mountain glaciers will continue to shrink and permafrost to thaw in all regions where they are present.
• Global warming has induced the earlier onset of spring snowmelt, with the increased melting of glaciers having already contributed to seasonal changes in streamflow in low-elevation mountain catchments. 
• Moreover, mountain glaciers are projected to lose more mass in higher greenhouse gas emissions scenario over the 21st century.
• Retreating snowlines and melting glaciers is a cause for alarm as this can cause a change in the water cycle, the precipitation patterns, increased floods as well as an increased scarcity of water in the future in the states across the Himalayas.

According to the predictions, the projected runoff is typically decreased by contributions from small glaciers because of glacier mass loss, while runoff from larger glaciers will generally increase with increasing global warming levels until their mass becomes depleted. 

• All of these changes will pose significant challenges for water supply, energy production, ecosystems integrity, agricultural and forestry production, disaster preparedness and ecotourism.

Global Scenario

• A rise in temperature has been recorded in the Himalayas, the Swiss Alps and the central Andes, and this has increased with altitude. 
• Such elevation-dependent warming could lead to faster changes in the snowline, the glacier equilibrium-line altitude and the snow/rain transition height.
• The report has further said that glaciers are melting and receding across the globe, including in the Himalayas, and that this is now a phenomenon that is “locked in’” and cannot be reversed. 
• It adds that the level of temperature rise in the mountains and glacial melt is unprecedented in 2,000 years. The retreat of glaciers is now attributed to anthropogenic factors and human influence.

About HKH Region

• It is often referred to as the ‘Third Pole’, on earth, is spread over 3,500 square kms across eight countries including India, Nepal and China.
• It contains the world’s third-largest storage of frozen water after Antarctica and the Arctic.
• Over 240 million people live in the region’s mountains. 1.7 billion live in the river basins downstream, while food grown in these basins reaches three billion people.
• The glaciers feed at least 10 major river systems, which have bearings on agricultural activities, drinking water and hydroelectricity production in the region.