Jun 25, 2024
HINDU KUSH HIMALAYAS: SNOW PERSISTENCE UPDATE
The Story So Far
In 2024, the Ganga river basin in India experienced a record low in snow persistence, as reported by the International Centre for Integrated Mountain Development (ICIMOD). Similar declines were noted in the Brahmaputra and Indus basins, threatening water supplies for millions. This decline is seen as a direct impact of the accelerating climate crisis.
What Is Snow Persistence?
Snow persistence refers to the amount of time snow remains on the ground. This is crucial as melting snow provides essential water for people and ecosystems. In the Hindu Kush Himalaya (HKH) region, snowmelt is a significant water source, contributing 23% of the annual runoff in the region’s 12 major river basins. The HKH mountains, spanning eight countries, are known as the “water towers of Asia” because they feed 10 major river systems, supporting nearly a quarter of the world’s population and providing freshwater to 240 million people in the region.
Key Findings of the Report
• Record Low Snow Persistence: The 2024 report shows significant fluctuations in snow persistence from 2003 to 2024. The Ganga river basin experienced its lowest snow persistence in 22 years, 17% below the long-term average. Similarly, the Brahmaputra and Indus basins also recorded significant drops.
• Global Comparison: Other basins, such as the Amu Darya and Helmand rivers, also saw record lows in snow persistence. Conversely, the Yellow River basin in China saw snow persistence 20.2% above normal, due to favorable interactions between cold air from the East Asian winter monsoon and moist air from the Pacific Ocean.
The Role of Climate Change
• Weak Western Disturbances: A primary reason for the lower snow persistence in 2024 is the weakening of western disturbances, which are low-pressure systems that bring rain and snow to the HKH region. High sea-surface temperatures have disrupted these weather patterns, leading to reduced winter precipitation and snowfall.
• Global Warming Effects: The instability caused by climate change and global warming exacerbates conditions like prolonged and intense La Niña–El Niño phases, further affecting weather patterns.
Importance of Snow Persistence
• Water Supply: Snowmelt contributes significantly to the water supply in major river basins. For example, it accounts for 10.3% of the Ganga basin’s water, 13.2% for the Brahmaputra, and about 40% for the Indus basin.
• Agricultural and Ecological Impact: Lower snow persistence can lead to water shortages, affecting agriculture and ecosystems dependent on these water sources.
Solutions and Mitigation
• Reforestation: Planting native tree species can help the ground retain more snow, improving water availability.
• Improved Forecasting: Better weather forecasting and early warning systems can help communities prepare for water stress.
• Infrastructure and Policies: Developing water infrastructure and creating policies to protect areas receiving snowfall are crucial for long-term sustainability.
• Reducing Emissions: Mitigating climate change by reducing emissions is essential. This involves transitioning away from fossil fuels, particularly among G-20 countries, which are responsible for the majority of global emissions.
Conclusion
The ICIMOD report highlights the critical need for comprehensive strategies to address the impacts of climate change on snow persistence in the HKH region. This includes both immediate measures to manage water resources and long-term efforts to reduce global emissions and enhance environmental sustainability.
SRIRAM’S
