The State of the Cryosphere 2025 Report by the International Cryosphere Climate Initiative (ICCI) warns that global ice loss is accelerating at an alarming rate, threatening catastrophic sea-level rise and water crises in Himalayan regions. 

• The report coincides with COP30 (Belém, Brazil, 2025).

Key Highlights of State of the Cryosphere 2025 Report

• Ice Sheets: Losses from the Greenland and Antarctic ice sheets have quadrupled since the 1990s, bringing them close to irreversible thresholds.
  • Impact: Several meters of sea-level rise over coming centuries are now likely inevitable. High emissions (warming ≥2°C) lock in >10 meters of unstoppable sea-level rise, threatening global coastal infrastructure, farmland, homes, and livelihoods.
• Polar Oceans: Rising greenhouse gases are severely damaging polar ocean functions like heat/carbon absorption, marine food webs, and global ocean circulation. 

• • Ocean acidification already reaches potentially lethal levels for shelled marine life at >430 ppm CO₂.
  • Impact: Two major circulation systems (Antarctic Overturning Circulation (AOC) and the Atlantic Meridional Overturning Circulation (AMOC)) have slowed substantially, likely due to freshwater melt and warming surface waters. 
    • At 2°C (≈500+ ppm CO₂), the risk of abrupt, irreversible circulation collapse and widespread species loss increases sharply, threatening global food security.
• Mountain Glaciers and Snow: Global glacier ice loss is increasing exponentially (273 gigatons per year from 2000–2023) with a 36% increase in the latter half. Snowpack thickness and duration are declining globally.
  • Impact: Heightened risks to water supply, agriculture, economies, and political stability for billions. Even under 1.5°C, High Mountain Asia could lose 60% of its ice; at 3°C, only 15% would remain.
• Sea Ice: Sea ice extent and thickness at both poles have declined 40–60% since 1979. Record lows occurred in 2023–2025 at both poles. Multi-year Arctic ice (4–7 years old) has nearly vanished.
  • Impact: Loss of polar sea ice accelerates Greenland/Antarctic melt, destabilizes weather patterns and ocean circulation, and threatens ice-dependent species. At ≥2°C warming, the Arctic becomes ice-free every summer, triggering high-risk global impacts.
• Permafrost: Over 210,000 km² of permafrost has thawed per decade for a century, accelerating since the 1990s.
  • Impact: Releases 0.3–0.6 Gt CO₂-eq per year, already equal to a top-10 emitter. 
    • Under 1.5°C warming, emissions reach ~India’s current level (~2.5 Gt/yr). 
    • At 3–4°C, permafrost emissions match the US/China (~5+ Gt/yr) for centuries, making carbon neutrality far harder and causing widespread infrastructure failure across the Arctic.

Factors Contributing to Cryosphere Melting

• Rising Greenhouse Gas Concentrations: Increasing CO₂, methane, and other greenhouse gases trap more heat in the atmosphere, rapidly warming polar and mountain regions
  • The cryosphere is extremely sensitive to even small temperature increases, making warming of 1°C–2°C enough to trigger massive ice loss.
• Accelerated Atmospheric Warming in the Arctic (Arctic Amplification): Loss of reflective snow and ice exposes darker land and ocean surfaces, causing them to absorb more heat and accelerate local melt.
• Ocean Warming and Freshwater Influx: Warm ocean waters melt ice shelves from below, especially in Antarctica and Greenland.
  • Freshwater from melting ice dilutes and lightens ocean surface waters, disrupting deep-water formation and slowing major currents like AMOC and AOC, further reducing the cryosphere’s resilience.
  • Thinning of Protective Ice Shelves: Ice shelves act as “barriers” holding back inland glaciers. Ocean warming is thinning these shelves, speeding the flow of land ice into the ocean and causing irreversible ice-sheet loss.
• Marine Heatwaves: Intense heatwaves in polar oceans melt sea ice rapidly and stress ecosystems.
  • Increase in warm-water intrusions accelerates breakup of sea ice and ice shelves 
• Black Carbon & Soot Deposition: Airborne pollutants from vehicles, crop burning, industry, and wildfires settle on snow and glaciers.
  • These dark particles reduce albedo (Surface Reflectivity), causing snow and ice to absorb more heat and melt significantly faster—especially in the Himalayas.
• Changes in Snowfall and Precipitation Patterns: Warming reduces overall snowfall and shifts precipitation from snow to rain in many regions.
  • Less winter snowpack exposes glacier ice earlier in the year, increasing melt duration.
• Human Land Use & Local Warming in Mountain Regions: Road construction, tourism infrastructure, and deforestation in high-altitude zones disturb glacier stability
  • Such activities contribute to local warming, dust deposition, and faster retreat in regions like the Himalayas and Andes.

Impact of Cryosphere Melting on the Ecosystem

• Permafrost Thaw Releases Methane & CO₂: Thawing permafrost releases massive amounts of ancient carbon (CO₂ and methane) previously locked in frozen soils.
  • Methane is 80× more potent than CO₂ over a 20 years period, accelerating global warming and creating dangerous climate feedback loops.
  • Permafrost regions also destabilize physically, altering tundra, forests, and wetland ecosystems.
• Loss of Sea Ice Disrupts Marine Food Webs: Sea ice supports algae that form the base of Arctic and Antarctic food chains.
  • Its decline reduces food availability for krill, fish, seabirds, penguins, seals, and whales, triggering collapse across entire ecosystems.
• Rising Sea Levels Flood Islands & Coastal Ecosystems: Melting glaciers and ice sheets contribute to rapid sea-level rise, submerging low-lying islands, mangroves, coral reefs, and coastal wetlands.
  • Saltwater intrusion damages freshwater ecosystems and erodes critical coastal habitats.
  • Entire island nations (Kiribati, Maldives, Tuvalu) face existential threats.
• Increasing Ocean Salinity in Some Regions, Freshening in Others: Melting ice adds freshwater to oceans, especially near Greenland and Antarctica, reducing salinity and altering nutrient distribution.
  • In tropical/subtropical regions, warming-driven evaporation increases salinity, stressing marine organisms.
  • These changes disrupt species distribution, breeding cycles, and food availability.
• Decrease in Albedo (Reflectivity): Loss of bright, reflective snow and ice exposes darker land and ocean surfaces.
  • Feedback Loop: This increases heat absorption, warming the planet further, an amplifying cycle known as the albedo feedback effect.
  • Lower albedo accelerates melt, expands ice-free regions, and disrupts temperature-sensitive ecosystems.
• Emergence of Dormant Diseases: Melting glaciers and thawing permafrost can expose long-buried viruses, bacteria, and spores.
  • These microorganisms, preserved for centuries or millennia, may re-enter ecosystems and infect wildlife and humans.
  • Example: The 2016 Siberian anthrax outbreak occurred when thawing permafrost exposed a decaying reindeer carcass, releasing spores that infected people and animals.
• Habitat Loss for Ice-Dependent Species: Polar bears, walruses, penguins, and seals depend on stable sea ice for hunting, breeding, and migration.
  • Melting ice forces species to travel farther for food, leading to starvation, reduced reproduction, and increased mortality.
• Ocean Circulation Disruption Alters Global Climate Patterns: Freshwater from melting ice weakens major ocean currents (e.g., AMOC, AOC).
• • These currents regulate temperature, nutrient cycling, and marine oxygenation, the disruption can collapse fisheries and oxygen-rich zones.
• Impact on Human Livelihoods & Nature-Based Livelihoods: Melting glaciers increase sediment load temporarily, damaging fish habitats. Communities depending on fishing, tourism, herding, and agriculture face economic decline due to environmental changes.
  • Melting glaciers reduce water availability for farming; coastal communities lose land; Arctic Indigenous groups lose hunting grounds.
  • Livestock, fisheries, and mountain agriculture are all under threat, destabilizing local economies.
• Loss of Snow Cover Disrupts Seasonal Ecosystems: Earlier snowmelt affects plant cycles, insect emergence, and animal migration
  • Snow-dependent species (snow leopards, mountain hares) lose protective camouflage and habitats.

Indian Government Initiatives for Cryosphere Preservation

• National Mission for Sustaining the Himalayan Ecosystem (NMSHE): A sub-mission under the National Action Plan on Climate Change (NAPCC).
  • Focuses on understanding climate impacts on the Himalayan cryosphere, promoting conservation, and building resilience of mountain communities.
• Centre for Cryosphere and Climate Change Studies: Established to promote advanced research on glacier dynamics, glacial lakes, and permafrost in the Indian Himalayan Region.
  • Supports real-time data collection, modelling, and risk forecasting.
• Use of Remote Sensing and GIS by ISRO: ISRO uses satellite-based glacier monitoring to track changes in glacier area, mass, and movement.
  • Enables early warning of glacial lake outbursts (GLOFs) and supports long-term climate modelling.
• Glacial Lake Outburst Flood (GLOF) Risk Mapping by NDMA: The National Disaster Management Authority has initiated zoning of GLOF-prone areas and the creation of early warning systems.
  • Aims to reduce disaster risk in high-altitude vulnerable zones.
• Research by National Institutes: Multiple institutions support India’s glaciology efforts:

• • National Centre for Polar and Ocean Research (NCPOR): Polar and high-altitude research.
  • NIH (Roorkee): Studies on hydrology and glacier melt contribution to rivers.
  • Wadia Institute of Himalayan Geology and G.B. Pant Institute: Cryosphere studies and ecological monitoring.
• International Cooperation & Climate Diplomacy: India reaffirmed its commitment to glacier preservation at the 2025 Dushanbe International Conference.
  • Emphasized the need for equity, CBDR-RC, and enhanced technology and finance flows to developing countries.

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Measures to Tackle Cryosphere Melting

• Accelerate Global Climate Action: Fast-tracking emission cuts under the Paris Agreement is essential to slow glacier retreat.
  • Studies show that limiting warming to 1.5°C could preserve ~50% of current glacier mass by 2100.
  • Achieve Net-Zero CO₂ by ~2045 and Net-Zero GHG by the 2060s: Reaching net-zero CO₂ around 2045 is essential to slow ice-sheet and glacier loss.
  • Net-zero all GHGs by the 2060s is required to stabilize temperatures and avoid runaway ice melt.
• Rapid Phaseout of Fossil Fuels: The report states about “There may be no negotiating with the melting point of ice.”
  • It emphasises phasing out coal in the 2040s, gas in the 2050s, and oil in the 2060s, with >95% elimination in each phase.
• Scale Up GLOF Early Warning Systems: Invest in predictive modelling, siren networks, and community-led disaster response drills.
  • NDMA’s efforts should be extended to all high-risk Himalayan glacial lakes, not just select zones.
• Reduce Methane, Black Carbon & Short-Lived Climate Forcers (SLCFs): Methane accelerates warming; black carbon directly accelerates glacier melt, especially in the Himalayas.
  • Reducing these pollutants limits overshoot and suppresses feedback loops like permafrost thaw.
• Accelerate Renewable Energy Expansion: The report requires tripling renewables by 2030, 6× by 2035, and 15× by 2050 to meet energy demand without fossil fuels.
• Scale Up Carbon Dioxide Removal (CDR) for Actual Temperature Decline: After reaching net-zero, temperatures fall only when CO₂ concentrations fall.
  • The report calls for large-scale afforestation and technological CDR (direct air capture, BECCS) to remove ~220 Gt CO₂ per 0.1°C of overshoot.
• Strengthen Adaptation: Prepare for Unavoidable Sea-Level Rise & Water Loss. Even with action, overshoot to 1.7–1.8°C is now unavoidable, demanding strong adaptation:
  • Strengthen coastal defenses
  • Plan for managed retreat
  • Improve water storage for glacier-fed basins
  • Protect infrastructure from permafrost thaw
    • The report warns the effectiveness of adaptation strategies will decline as warming escalates, so action must be early and proactive.
• Institutionalize Transboundary Cooperation: Foster Himalayan climate diplomacy for data sharing, joint risk mapping, and ecosystem management.
  • Platforms like ICIMOD should be empowered for coordinated regional glacier governance.
• Ensure Climate Finance and Tech Transfer: Push for equitable funding and technology sharing to build glacier adaptation capacity in the Global South.
  • India’s call at Dushanbe 2025 emphasized Common But Differentiated Responsibilities (CBDR-RC) for glacier protection.
• Promote Eco-sensitive Development and Tourism: Enforce environmental clearances for infrastructure and regulate tourism in fragile glacial zones.
  • Avoid construction near retreating glaciers and vulnerable valleys, as in the case of Kedarnath and Joshimath.

Conclusion 

Cryosphere preservation is now a global survival imperative, only deep, urgent, and sustained emission cuts can prevent irreversible planetary-scale damage.

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