South Asia stands at the epicentre of a crisis that threatens its very foundation: The convergence of climate change and water insecurity. Home to a quarter of the world’s population, the region is experiencing what scientists call “unprecedented and largely irreversible” changes to its water systems. Manifestations are already visible and deadly: Scorching temperatures reaching 48.5°C in Pakistan’s Gilgit-Baltistan, followed by cloudbursts and flashfloods that have claimed more than 700 lives in the last three months in Pakistan. In India, extreme weather events have taken a toll in all parts of the country, from the mountains to the coasts and the plains. Hundreds of unstable glacial lakes are threatening millions downstream. The stakes could not be higher: By 2030, 90 per cent of South Asia’s population will face extreme heat exposure, while 20 per cent will confront severe flooding.
The Hindu Kush Himalayan region, often called the “Third Pole,” is experiencing catastrophic transformation at a pace that has left climate scientists reeling. The latest assessment from the International Centre for Integrated Mountain Development reveals that glaciers in this critical region disappeared 65 per cent faster in 2011-2020 compared to the previous decade and could lose up to 80 per cent by century’s end. The Hindu Kush Himalayan glaciers feed 12 rivers flowing through 16 countries, providing freshwater to 240 million mountain dwellers and 1.65 billion people downstream.
Accelerated glacial melt has created hundreds of unstable glacial lakes across the region. Over 200 glacier lakes are deemed dangerous, with glacial lake outburst floods (GLOFs) posing imminent threats. The 2023 GLOF in Sikkim demonstrated the devastating potential, while Pakistan’s recent deadly flooding from rapid glacier melt killed many people and destroyed critical infrastructure.
South Asia’s monsoon system, once a reliable seasonal rhythm, has transformed into an unpredictable force of destruction. The World Meteorological Organisation forecasts continued hefty rainfall across the region from 2025 to 2029, alongside rising global temperatures and increased extreme events. It’s a fundamental shift in how water moves through the region.
The consequences are deadly. Intense rainfall events followed by prolonged dry spells have become the new normal, disrupting agricultural cycles and overwhelming water infrastructure. The monsoon’s increasing volatility particularly affects the region’s agricultural communities, creating cascading effects on food security and rural livelihoods.
Snow cover is projected to fall by up to 25 per cent under high emissions scenarios, drastically reducing freshwater for major rivers that depend heavily on snow and glacier melt. The Amu Darya relies on it for up to 74 per cent of its flow, the Indus for 40 per cent, and the Helmand for 77 per cent. This dramatic reduction in water availability will fundamentally reshape human settlement patterns and economic activity across the subcontinent.
While surface water challenges dominate headlines, an invisible crisis unfolds beneath South Asia’s feet. Groundwater tables are falling rapidly, more than one metre per year in dry areas, due to over-extraction and changing recharge patterns. This groundwater depletion has decoupled from rainfall patterns, creating a dangerous dependence on depleting aquifers.
India’s per capita freshwater availability is projected to drop below 1,000 cubic meters by 2025, officially classifying it as water-scarce. The situation is particularly acute in urban areas where rapid, unplanned growth has overwhelmed infrastructure. Cities like Mumbai face a double threat: Intensified heatwaves due to urban heat islands and increased flood risk from compromised drainage systems and encroached floodplains.
By 2050, millions in South Asia, especially in urban poor communities, could face increased water scarcity unless urban planning and governance improve dramatically. The need for better groundwater governance and community engagement has never been more urgent.
Perhaps the most troubling aspect of South Asia’s water crisis is the breakdown of cooperative frameworks precisely when they’re needed most. The Indus Waters Treaty, a cornerstone of regional water management, is under unprecedented strain. India’s suspension of the treaty raises fears for Pakistan’s downstream water security, especially as climate change already reduces flows. Millions lost water access during the 2022 floods.
South Asia’s transboundary water-sharing mechanisms are fundamentally outdated, unable to address climate-induced variability driving new geopolitical pressures. Over 90 per cent of the region’s surface water crosses international borders, yet existing treaties remain largely divorced from climate realities. This governance gap creates a dangerous vacuum where water scarcity becomes a driver of conflict rather than cooperation.
The situation exemplifies a broader problem: Most South Asian countries maintain separate climate and water strategies with minimal institutional coordination. This fragmentation results in duplicated efforts, conflicting objectives, and missed opportunities for synergistic solutions that could address both climate adaptation and water security simultaneously.
The human costs extend far beyond statistics. By 2025, 1.3 million people in Nepal are estimated to be displaced by climate-related disasters. Coastal regions like Bangladesh’s Sundarbans face salinity intrusion, threatening freshwater systems and traditional livelihoods. Vulnerable mountain communities are already experiencing adverse impacts, with disasters causing loss of life, property, heritage, and infrastructure, driving displacement and leaving lasting psychological scars. The effects cascade through fragile mountain ecosystems, with species decline and extinction already reported. With 67 per cent of the Hindu Kush Himalayan ecoregions remaining outside protected areas, nature is particularly vulnerable to accelerating climate impacts.
The “missing link” isn’t just about connecting climate and water policies; it’s about recognising that water security underpins all other development goals. Current funding flows to the region are woefully insufficient for the scale of challenges ahead. Scientists predict devastating consequences for water and food security, energy sources, ecosystems, and the lives of hundreds of millions of people, many of which will exceed the limits of adaptation.
The time for incremental change has passed. South Asia needs urgent international support, regional cooperation, and transformative approaches that acknowledge the unprecedented nature of the crisis. Every increment of warming matters to glaciers and the hundreds of millions who depend on them. The choice is stark: transform or face catastrophe. The glaciers won’t wait for political convenience, and the monsoons won’t align with bureaucratic timelines. South Asia must forge the missing link between climate action and water security now, before the window for meaningful action closes forever. The clock is ticking.
The writer is Senior Director of the international think tank IPAG India, which also has a presence in Dhaka, Melbourne, Dubai and Vienna
Two separate cloudbursts at Jodh Ghati and in the Janglote area of Kathua district had claimed seven lives, including five children, on Sunday. 
Share
