Climate Change and the Gangotri Glacier System

The most recent studies emphasize the increased influence of climate change on the Gangotri Glacier System (GGS), a vital Himalayan glacier that supplies the Ganga river. Temperature and precipitation variations over the past 30 years (1980-2020) have greatly changed its hydrology, and the effects have been severe in terms of agriculture, hydropower, and water supply of the North Indian region.

Gangotri Glacier System

• one of the middle Himalayas' biggest glaciers.
• Millions downstream supported by Lifeline of the Ganga.
• The river flow is a result of snowmelt, glacier melt, rainfall-runoff and base flow, snowmelt has historically dominated at 64%.

Hydrological Shifts

• The contribution to snowmelt decreased to 63% (2010-20) compared with 73% (1980-90).
• Glacier melt: 21%, Rainfall-runoff: 11%, Base flow: 4%.
• There is an increase in temporary snowmelt rise (2010-20), the result of colder winters and more snow.

Warming and Flow Changes

• Mean temperature in the regions increased by 0.5degC (2001-20 vs 1980-2000).
• Previous summer melting changed the peak discharge to July.
• The thickness of the glaciers is dwindling by 46 cm/yr; snout remains receding.

Declining Snow Cover

• Snow space diminishing, diminishing snowmelt mass.
• Rainfall-runoff and base flow was intensified, and to some extent, equivalent to losses.

Water Security Risks

• Past peak flows can lead to crunch at the end of the summer.
• Lower dry-season flow poses a risk to irrigation and hydropower.
• The loss in the mass of glaciers over a long period of time is an indicator of escalating stress on the Ganga basin.