Why India needs to worry about melting glaciers.

• If adequate steps are not taken to limit global warming, two-thirds of glaciers in the Hindu Kush Himalayas could melt by 2100

• Hindu Kush is Asia’s water tower, providing a vital regional lifeline to over two billion people through 10 main river

A new study has said that if adequate steps are not taken to limit global warming, two-thirds of glaciers in the Hindu Kush Himalayas could melt by 2100, and large increases in run-off could lead to flooding of major rivers. Mint analyses the major findings of the study.

What are the main findings of the study?

The Hindu Kush Himalayan region is of critical importance, given that it holds the largest ice mass after the North and South Poles, and has been on a constant warming trend since the 1970s. The study warns that if global efforts to limit global warming to below 2°C above pre-industrial levels fail, it could lead to the melting of two-thirds of the region’s glaciers by 2100. This could be catastrophic, given that there are 8,790 glacial lakes in the region, of which 203 could lead to floods from glacial lake outbursts. On an average, 76 events of natural hazard occur every year in the Hindu Kush, with China accounting for 25 and India 18.

How could warming in the Himalayas destabilize rivers?

Hindu Kush is Asia’s water tower, providing a vital regional lifeline to over two billion people through 10 main rivers that originate from the glaciers. Increasing glacial melts could destabilize these rivers by changing their stream flow. The Indus could witness more stream flow due to high glacial melt till 2050, after which the flow would start reducing due to decreasing glacial melt. The Ganga and the Brahmaputra, which are mainly monsoon-fed rivers, will also see variations, as pre-monsoon flows may decline. This will hamper agriculture that accounts for the largest share of water usage.

Are rising pollution levels contributing to the crisis?

The Indo-Gangetic Plain, an extremely polluted region, has amplified the effects of greenhouse gases. Deposits of black carbon and dust have sped up the melting of Hindu Kush glaciers.

What could be the impact on monsoons?

The Hindu Kush range exerts a significant influence on seasonal shifts in the monsoon circulation and the distribution of rainfall over Asia in summer. The south-west monsoon accounts for 70% of the annual rainfall in India. Projections for the region indicate a likely increase in summer rainfall by 4-12% in the near term and 4-25% in the long term. Changing monsoon patterns, including increased severity and frequency of storms, could lead to mountain hazards that may destroy critical infrastructure.

Could there be a threat of forced environmental migration?

Researchers say that forced migration could occur with an increase in the incidence and magnitude of extreme events such as floods. There could be large-scale demographic movements. The annual rate of increase in migration in the countries of the Hindu Kush Himalayas has been disturbingly high and the number of internally displaced people is also expected to rise. The region will have many more people in vulnerable urban areas in the next 20 years, says the study.