The Hindu Kush Himalayan (HKH) region is a vast area covering over 4.2 million square km and stretching from Afghanistan to Myanmar, including parts of Pakistan, India, China, Nepal, Bhutan, and Bangladesh. It is known for its highest mountain ranges, extensive ice and snow cover, and rich biodiversity. The region is home to unique cultures and all peaks above 7,000 meters.
The HKH plays a crucial role in providing water resources, as it serves as the source for 12 major rivers, including the Ganges, Brahmaputra, and Indus, which flow through 16 Asian countries and support the lives of millions of people. However, the HKH cryosphere, which includes glaciers, snow, and permafrost, is undergoing unprecedented and largely irreversible changes due to climate change. This has led to increased warming, accelerated glacier melting, permafrost thawing, and changes in snowfall patterns.
These cryospheric changes have significant consequences for both mountain communities and downstream regions. Mountain communities are already experiencing the impacts through altered water availability, increased hazards, and disrupted livelihoods. Downstream infrastructure, human settlements, and economies are also at risk. Flooding, landslides, and uncertainty in water resources pose threats to agriculture and the livelihood security of millions of people.
The new ICIMOD’s HI-WISE assessment report shows this gap by providing updated information on the rapidly changing cryosphere in the HKH and its impacts on water, biodiversity, and societies. I outline the major findings of this report.
Alarming Signs of Glacier Mass Loss and Snow Cover Decline
Recent advances in monitoring and analysis have revealed significant changes in the cryosphere of the Hindu Kush Himalayan (HKH) region. Glaciers in the HKH have experienced a 65% increase in mass loss, and the Karakoram region has transitioned from a state of mass gain to mass loss. The most negative mass balances are observed in the eastern part of the HKH. Snow cover extent in the HKH has shown a clear negative trend since the early 21st century, with a decrease in seasonal snow cover during summer and winter months, indicating a shift in seasons.
The decline in snow cover days is particularly notable at lower elevations. Future projections suggest an accelerated loss of snow cover in the HKH under different global warming scenarios. Permafrost, though poorly understood, is also experiencing changes, with a decrease in permafrost occurrence confirmed by field observations and remote sensing. Modelling indicates a loss of permafrost area in the western Himalayas and the Uttarakhand Himalayas. On the Tibetan Plateau, permafrost degradation is expected to increase, with a significant portion degrading by 2071-2099 under high emissions scenarios.
Changing Dynamics of Water Availability and Hazards
The accelerated melt of glaciers is projected to lead to a "peak water" scenario in most river basins by the mid-century, followed by an overall decrease in water availability by the end of the century. However, there is large variability between basins, and uncertainties in future precipitation projections limit confidence in estimating future water discharge. Improved projections of precipitation, snow water equivalent, and other fluxes are crucial for accurately assessing future water availability.
The changing climate and increased exposure to hazards have made the mountain hazard landscape in the HKH region multidimensional. Various slow-onset hazards such as sedimentation and erosion, as well as fast-onset hazards like floods and glacial lake outburst floods (GLOFs), occur simultaneously and often cascade, making early warning and adaptation challenging. While there is medium confidence in the likely increasing trend of future hazard frequency and intensity, the confidence levels vary across hazards, with glacier retreat and heavy precipitation events showing clear trends.
Impacts of Cryospheric Change on Ecosystems in the HKH
The cryosphere HKH region plays a vital role in supporting ecosystems, maintaining biodiversity, and providing essential ecosystem services. Approximately 60% of the region features a seasonal cryosphere, including snow, glaciers, permafrost, and glacial lakes, which serve as significant water sources and providers of ecosystem services. With 40% of the region under protected area coverage, the HKH is known for its interconnected and diverse ecosystems.
However, the fragile HKH ecosystem and cryosphere are facing multiple drivers of change, predominantly climate change, which has cascading impacts on surrounding ecosystems and human well-being. Climate change-induced cryospheric changes, such as glacier mass loss, reduction in snow cover, permafrost shrinkage, and altered hydrology, are leading to widespread ecosystem degradation, and increased natural hazards. Species are shifting to higher elevations, habitats are becoming less suitable, and invasive species are encroaching, negatively impacting both biodiversity and the flow of ecosystem services. These changes significantly affect the vulnerability of both ecosystems and people, disrupting social-ecological resilience.
Future scenarios indicate alarming trends at the ecosystem and species levels, including increased vulnerability, reduced ecosystem services, and imbalances in ecosystem functions, leading to heightened societal vulnerability. The cascading effects of cryospheric loss are expected to further degrade ecosystems and alter species composition, posing significant challenges to the well-being of both the natural environment and human communities in the HKH region.
Enhancing Adaptation for Sustainable Mountain Societies
Adaptation to the changing conditions in the HKH region is of utmost importance to ensure sustainable mountain development and the well-being of mountain societies. It is crucial to adopt integrated approaches that synergize sectoral policies and address the diverse challenges faced by these communities.
To achieve sustainable development in mountainous areas, policies must effectively address the multifaceted pressures confronting these societies. This entails enhancing their capacity to adapt swiftly, comprehensively, and deeply. By adopting coordinated and holistic approaches, policies can support mountain communities in building resilience and effectively responding to the impacts of environmental changes.
The development of adaptation strategies and policies that consider the unique socio-cultural, economic, and ecological characteristics of the HKH region is vital. These efforts should encompass various sectors, such as water management, agriculture, infrastructure, and disaster risk reduction. By integrating adaptation measures into multiple sectors, sustainable development can be fostered, enabling mountain societies to thrive in the face of evolving challenges.
Navigating Cryospheric Changes: A Call for Action
The HKH region is at a critical crossroads as the cryosphere, encompassing snow, glaciers, and permafrost, faces accelerated changes due to climate change. As these icy realms melt at an alarming rate, the consequences reverberate across ecosystems and societies, necessitating swift and coordinated policy responses.
Here are five key policy messages from the report that demand urgent attention:
1. Integrated Water Management: Water is the lifeblood of the HKH region, and understanding the contributions of different water resources is paramount. Decision-makers must identify the dominant water sources in their respective basins to prioritize investigations and adaptation measures. By preparing for seasonal shifts in water availability and anticipating future changes, they can mitigate the adverse effects on downstream water usage and minimize water-related hazards. Robust modelling and forecasting of water supply, considering both upstream meltwater and downstream demand, will facilitate effective water resource management.
2. Multi-Hazard Preparedness: The changing cryosphere poses a heightened risk of multi-hazard events and cascading disasters. Adapting to this complex reality requires comprehensive strategies that account for multiple hazards and their interplay. Monitoring solutions that capture diverse processes is crucial for evaluating impacts accurately. Simulations involving various concurrent scenarios can help assess the full extent of risks, preventing maladaptation and reducing overall vulnerability. By embracing an all-encompassing approach, decision-makers can enhance disaster preparedness and safeguard lives and livelihoods.
3. Ecosystem Resilience: The intricate web of ecosystems in the HKH region is facing unprecedented challenges. As the cryosphere shrinks, it triggers a domino effect on ecosystems and the species they support. Understanding these complex interlinkages is essential for designing effective interventions and bolstering ecosystem resilience. Increased investment in scientific research is urgently needed to unravel the intricate connections between climate change, cryospheric changes, ecosystems, and society. By enhancing our understanding, we can develop targeted strategies to protect biodiversity, restore habitats, and ensure the continued provision of vital ecosystem services.
4. Regional Cooperation: The HKH region is a shared global asset, referred to as the "Water Tower of Asia," as it provides water and ecosystem services to a quarter of humanity. Preserving this shared heritage necessitates strong regional cooperation. By fostering collaboration among nations, sharing knowledge, and pooling resources, we can tackle the transboundary challenges posed by cryospheric changes. The implementation of the HKH Call to Action, alongside South-South cooperation, offers promising avenues for collective action. Together, we can champion sustainable mountain environments and uplift the livelihoods of millions.
5. Inclusive Adaptation Policies: As we respond to the changing cryosphere, it is vital to prioritize social and environmental justice principles. Vulnerable and marginalized communities in the HKH region face disproportionate risks and must be at the centre of adaptation policies. Safeguarding their non-economic assets, such as cultural heritage and spiritual beliefs, is critical for societal well-being. By incorporating inclusive approaches into policy frameworks, we can ensure that adaptation efforts are equitable, empowering, and responsive to the needs and aspirations of all.
(Anjal Prakash is a Clinical Associate Professor (Research) and Research Director- at the Bharti Institute of Public Policy at ISB. He contributes to IPCC reports. This is an opinion piece and the views expressed above are the author’s own. The Quint neither endorses nor is responsible for the same.)
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