Two-degree temperature rise could melt half of glaciers in Hindu Kush Himalaya region, destabilizing Asia’s rivers: Study

If global climate efforts fail, the study warns that current emissions would lead to five degrees in warming and a loss of two-thirds of the region’s glaciers by 2100.

“This is the climate crisis you haven’t heard of,” said Philippus Wester of the International Centre for Integrated Mountain Development (ICIMOD), who led the report.

“Global warming is on track to transform the frigid, glacier-covered mountain peaks of the HKH cutting across eight countries to bare rocks in a little less than a century. Impacts on people in the region, already one of the world’s most fragile and hazard-prone mountain regions, will range from worsened air pollution to an increase in extreme weather events. But it’s the projected reductions in pre-monsoon river flows and changes in the monsoon that will hit hardest, throwing urban water systems and food and energy production off kilter.” 

Styled after the Intergovernmental Panel on Climate Change (IPCC) reports, the Hindu Kush Himalaya Assessment is the first and most authoritative study of its kind to provide an assessment of one of the world’s most significant, yet often overlooked, mountain regions. 

Developed over five years, it includes insight by more than 350 researchers and policy experts from 22 countries and 185 organizations. With 210 authors, 20 review editors and 125 external reviewers, it provides an unprecedented insight into the region’s distinct environment, people and wildlife. 

“The massive size and global significance of the Hindu Kush Himalaya region is indisputable, yet this is the first report to lay down in definitive detail the region’s critical importance to the well-being of billions and its alarming vulnerability, especially in the face of climate change,” said David Molden, director general of ICIMOD.

The authors used a range of approaches, including climate modelling, to write the report.   

The HKH region covers 3,500 kilometers across Afghanistan, Bangladesh, Bhutan, China, India, Myanmar, Nepal and Pakistan. Nestled in its record-breaking peaks, glaciers feed 10 of the world’s most important river systems, including the Ganges, Indus, Yellow, Mekong and Irrawaddy, and directly or indirectly supply billions of people with food, energy, clean air and incomes. Additionally, the region contains four of the world’s biodiversity hotspots.

Though the mountainous region was formed around 70 million years ago, its glaciers are extremely sensitive to the changing climate.

Since the 1970s, when global warming first set in, these ice masses have steadily thinned and retreated, and snow-covered areas and the amount of snow have decreased.

These changes have ripple effects felt throughout the region.

When glaciers melt, they flow into lakes and rivers. Changes to the timing and magnitude of this melting leads to an increase in the number and size of glacier lakes, which can suddenly flood.

This can lead to a surge of glacier runoff into major rivers, which could lead to flooding and the destruction of crops.

As a result of the HKH ice melt, more water is expected to surge through the Indus, Ganges and Brahmaputra rivers, forcing a change to the agriculture in the valleys around them. 

Greenhouse gases are exacerbated by air pollutants originating from the Indo-Gangetic Plains—one of the world’s most polluted regions. These pollutants deposit black carbon and dust on the glaciers, hastening their melting and changing monsoon circulation, and rainfall distribution over Asia.

As the Nepal earthquake in 2015 laid bare, mountain cities and settlements are vulnerable to disasters—from landslides and erosion to debris flows and floods. As the number and intensity of these disasters increase, more than one billion people are at risk.

These changes hit the region’s poor hardest. About one-third of the 250 million HKH mountain people live on less than $1.90 a day; more than 30 percent of the region’s population doesn’t have enough to eat, and around 50 percent face some form of malnutrition, with women and children suffering the most. The realities of mountain life, such as inaccessibility, fragility and remoteness, make it difficult for people to earn a living in the region; nonetheless, the report points out that mountain people have the potential to earn incomes by better utilizing the region’s resources, such as hydropower potential. 

For example, HKH has a huge hydropower potential of ~500 gigawatts, enough to power half a billion homes in the region. Nonetheless, more than 80 percent of the rural population, most of whom live in mountain regions, rely on traditional fuels, such as firewood or dung, for cooking, and about 400 million people in HKH countries still lack basic access to electricity.

Despite the cultural and political diversity of the countries studied, they are united in the unique challenges facing mountain regions, which will only get worse with climate change and glacial melt, the report argues. 

“There are rocky times ahead for the region: between now and 2080, the environmental economic and social conditions laid out in the report could go downhill,” said Eklabya Sharma, deputy DG of ICIMOD. “Because many of the disasters and sudden changes will play out across country borders, conflict among the region’s countries could easily flare up. But the future doesn’t have to be bleak if governments work together to turn the tide against melting glaciers and the myriad impacts they unleash.”

The report also calls for great recognition of mountain areas and the HKH region in global climate efforts.

“We need to start thinking of mountain regions as climate hotspots worthy of urgent attention, investments and solutions,” Dasho Rinzin Dorji, ICIMOD board member from Bhutan, said.