• The warming rate over the last 50 years in the HKH has been 0.2 ̊C per decade.
• Extreme indices in the region have also changed over this period: occurrences of extreme cold days and nights have declined (days by 0.85 days per decade, nights by 2.40 days per decade), while occurrences of extreme warm days and nights have increased (days by 1.26 days per decade, nights by 2.54 days per decade).
• Warm nights have increased throughout the region, and extreme absolute temperature indices have changed significantly..
Assessment of Hindu Kush Himalaya
• The ‘Hindu Kush Himalaya Assessment’ released Monday by the Kathmandu-based International Centre for Integrated Mountain Development (ICIMOD).
• It provides insights into changes affecting one of the greatest mountain systems in the world.
• Even the most ambitious goal set by the Paris Agreement to limit global warming would lead to a 2.1 spike in temperature in the HKH region leading to melting of one-third of the region’s glaciers.
• It also points out that the Tibetan Plateau, Central Himalayan Range and Karakoram will warm more than the HKH average.
• Even if efforts are made to limit global warming to 1.5̊C by the end of the Century, the Hindu Kush Himalaya will warm by around 1.8 ̊C, a comprehensive report on the region has found.
• The report also finds that warming will at least be 0.7 ̊C higher in the northwest Himalaya and Karakoram region.
• The HKH will warm more than the global mean and more rapidly at higher elevations.
• The report warns that extremes in precipitation are increasing in the HKH region. “The number of intense precipitation days and intensity of extreme precipitation have increased overall in the last five decades.
• If these trends persist the frequency and magnitude of water-induced hazards in the region will increase in the future,” it states.
• It, however, points out that consensus among climate models for the region is “weak” which is a result of the area’s complex topography and the coarse resolution of global climate models.
• The report notes that the cryosphere -parts of the Earth system where water is in frozen form- is an important part of the water supply of the extended HKH.
Addressing climate change
• The report also addresses the large impacts of air pollution on the HKH.
• “The HKH is sensitive to climate change air pollutants originating within and near the HKH amplify the effects of greenhouse gases and accelerate melting of the cryosphere through the deposition of black carbon and dust, and changing monsoon circulation and rainfall distribution over Asia,” it states.
• The report calls for greater recognition of mountain areas and the HKH region in global efforts.
About Hindu Kush-Himalaya
• HKH covers 3500 kms across eight countries – Afghanistan, Bangladesh, Bhutan, China, India, Myanmar, Nepal and Pakistan –
• It is the source of ten major river basins including the Ganges, Brahmaputra and Indus in India.
• Two billion people are dependent on the HKH for their water needs across Asia.
• Glaciers in the HKH region are a critical water source for some 250 million people in the mountains as well as to 1.65 billion others in the river valleys below.
Mains Paper 1: Geography | Changes in critical geographical features including water-bodies & ice-caps
Prelims level: Hindukush Range
Mains level: Impact of global warming on Himalayas