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Landmark International Report: Current Emissions Path Threatens Two Billion People in Hindu Kush Himalayas

A major new assessment report released today reveals the changes to the glaciers, snow and permafrost of the Hindu Kush Himalaya (HKH) region driven by global warming are “unprecedented and largely irreversible.”

The study, titled “Water, Ice, Society, and Ecosystems in the Hindu Kush Himalaya,” comes from the International Centre for Integrated Mountain Development, an intergovernmental institution with eight member-countries based in the HKH region. The report maps the links between the cryosphere, water, biodiversity, and society in the region, charting the impacts of rapid changes in glaciers and snow on people and nature.

sunlight on snowy mountaintops
The glaciers and snow of the over 3,000 named peaks in the Himalayas are an important water resource that climate change threatens to destroy. Photo: Koshy Koshy/Flickr

Ice and snow in the HKH are an important source of water for 12 rivers that flow through 16 countries in Asia, providing freshwater and other vital ecosystem services to 240 million people in the mountains and a further 1.65 billion people downstream, according to the report. Vulnerable mountain communities are already experiencing major adverse impacts—including disasters causing loss and damage to lives, property, heritage, and infrastructure, leading to displacement and psychological impacts.

The report’s publication comes after cryosphere scientists at the Bonn Climate Change Conference earlier this month sounded the alarm at the speed and scale of ice-melt worldwide, which is far outpacing worst-case scenario projections from the Intergovernmental Panel on Climate Change. This meeting, called the 58th Session of the UN Climate Change Subsidiary Bodies, is a major lead up to the annual global climate meeting, COP28, which will be held in the United Arab Emirates in December.

Glaciers in the HKH could lose up to 80% of their current volume by the end of the century based on current emissions trajectories, according to the report. Snow cover is projected to fall by up to a quarter under high emissions scenarios—drastically reducing freshwater for major rivers such as the Amu Darya in Afghanistan and several Central Asian countries, where it contributes up to 74% of river flow, including the Indus (40% river flow) in India and Pakistan, and the Helmand (77% river flow) in Iran and Afghanistan. Permafrost is also decreasing in the region, which will lead to more landslides and problems for infrastructure at high elevation.

river valley
Both the Indus River (pictured above) and the Helmand River are glacier-fed and have been the sites of intense water disputes and conflicts between the countries that utilize them. Photo: McKay Savage/Flickr 

The study warns that communities and governments need urgent support and finance to prepare for the accelerated impacts on societies and nature that cryosphere changes will cause as temperatures rise, with current funding flows to the region “woefully insufficient” to the scale of the challenges the region will face. Scientists predict devastating consequences for water and food security, energy sources, ecosystems, and the lives and livelihoods of hundreds of millions of people across Asia, many of which will be beyond the limits of adaptation.

Izabella Koziell, deputy director general of the International Centre for Integrated Mountain Development, said in a press release, “With two billion people in Asia reliant on the water that glaciers and snow [the HKH] holds, the consequences of losing this cryosphere are too vast to contemplate. We need leaders to act now to prevent catastrophe. As this study shows, alongside urgent mitigation action, we need adaptation funds and programmes and ecosystem restoration to be rapidly scaled up, and the mobilization of finance for losses and damages.”

The study found that availability of water in the HKH is expected to peak by 2050, driven by accelerated glacial melt. Then it is projected to decline, with local variability in meltwater from glaciers and snow resulting in huge uncertainty for mountain communities and large lowland populations.

Floods and landslides are also projected to increase over the coming decades, with slow-onset hazards, such as sedimentation and erosion and fast-onset hazards such as glacial lake outburst floods. Two-hundred glacier lakes across the HKH are deemed dangerous, and the region could see a significant spike in the risk of glacial lake outburst floods by the end of the century. Coupled with increased population growth and economic activity in the region, the exposure to these hazards poses the risk of increased loss and damage, including population displacement.

The report found that the effects of the changing cryosphere on fragile mountain habitats are particularly acute, with cascading impacts reported in most ecosystems and affecting most inhabitant species. Species decline and extinction have already been reported, along with the movement of species to higher elevations, ecosystem degradation, decrease in habitat suitability, and invasion of alien species. “With 67% of the HKH’s ecoregions and 39% of the four global biodiversity hotspots located in the HKH remaining outside protected areas,” the region’s ecosystems are particularly vulnerable to climate impacts, according to the report.

“There is still time to save this critical region, but only if fast and deep emissions cuts start now,” said Koziell. She indicated that every small fraction of a degree of warming impacts the glaciers in the region, with harsh consequences for the hundreds of millions of people that depend on them.

Philippus Wester, lead editor of the report and a fellow at the International Centre for Integrated Mountain Development, emphasized the need for immediate action in an interview with GlacierHub, saying, “We now know with very high confidence that at 2 degrees Celsius, global warming the region will lose 50% of its glacier volume by 2100, while at 1.5 degrees this will only be 30%. This large difference shows that every increment of warming matters.” He  deemed the report a “clarion call” to urgent climate action, in order to protect the environment, health, livelihood, and well-being of the 240 million people in the region.

Miriam Jackson, an intervention manager for cryosphere risk at the International Centre for Integrated Mountain Development, offered a succinct summary of the new report to GlacierHub: “Things are changing fast in the Hindu Kush Himalaya. Just from one decade to the next, we have seen a dramatic increase in glacier melt. Our data and knowledge of this region are also increasing fast. The question is, can people in these mountain regions adapt just as fast?”

Science for the Planet: In these short video explainers, discover how scientists and scholars across the Columbia Climate School are working to understand the effects of climate change and help solve the crisis.
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