Two-thirds of the Himalayan and Hindu Kush glaciers could melt by the end of the century if the planet stayed on the same trajectory of greenhouse gas emissions, threatening to destabilize major rivers.
Stretching 3500 kilometers from Afghanistan to Burma, the Hindu-Kush-Himalayas (HKH) mountainous region is known as the -third pole- by scientists for its huge ice reserves. These feed ten major rivers in Asia, from the Ganges to the Mekong through the Yellow River, along which are structured population basins.
But global warming is threatening the glaciers at high altitude of this mountainous line which counts the highest summits of the world as Everest and K2, according to a vast study, fruit of five years of work and which mobilized more 350 researchers and experts, led by the International Center for Integrated Mountain Development (ICIMOD), an intergovernmental organization established in Kathmandu, Nepal.
-It’s the climate crisis you have not heard about,- said Philippus Wester, head of the ICIMOD report, quoted in the press release.
Even if the nations of the planet managed to contain the global warming of the globe at + 1.5 ° C compared to the pre-industrial era by 2100, the low target of the Paris agreement on the climate of 2015, the Hindu-Kush-Himalayas would still lose a third of its glaciers. This melting will not be without consequences for the 250 million inhabitants of these mountains and the 1.65 billion others who live in the river basins downstream.
-Global warming is turning mountainous peaks covered by HKH glaciers into eight bare rock countries in less than a century. The consequences for the peoples of the region, already one of the most fragile and risky mountain regions in the world, will range from a worsening of air pollution to an increase in extreme weather events, -he said. keep Mr. Wester.
By influencing the volumes and periods of glacial melt, global warming threatens agricultural production dependent on this water and poses a risk of food insecurity, both in the mountains and below.
-Projected reductions in pre-monsoon flows and changes in the monsoon will hurt the most, disrupting urban water systems and the production of food and energy,- Wester said.
More frequent droughts, increased rainfall and sudden floods due to glacial lake failures are among the climatic hazards cited by the study. And -more water should flow in the Indus, Ganges and Brahmaputra,- forcing a change in agriculture practiced in the valleys near these rivers, she notes.
High in the Indo-Gangetic plains, atmospheric pollution also causes the deposit of carbon black and dust on glaciers. This phenomenon has the effect of accelerating their melting, to modify the monsoon circulation and the rainfall distribution over Asia.
The report estimates that it will be necessary to inject $3.2 to $4.6 billion per year in the region by 2030 to adapt to climate change, and then to 5.5 to 7, $8 billion a year by 2050.
-All countries (Hindu-Kush-Himalayas) share mountain resources so it is necessary that they work together to determine how to tackle this problem and also speak with one voice on the world stage-, said David Molden, the director general of ICIMOD.