2025年世界水资源发展报告_174页_12mb

Summary of the United Nations World Water Development Report 2025 – Mountains and glaciers: Water towers

Core Content

The United Nations World Water Development Report 2025 – Mountains and glaciers: Water towers is a comprehensive assessment of the role of mountain and glacial systems in global water security. It emphasizes the critical importance of these "water towers" in providing fresh water to billions of people and ecosystems, and highlights the growing threats they face due to climate change and unsustainable human activities.

Main Points

• Mountains as Water Towers:
  Mountains cover 33 million km² and are home to over 1.1 billion people. Additionally, 2 billion people downstream rely on mountain-derived water resources for their freshwater supply. Mountains are crucial for water supply, sanitation, food and energy security, and ecosystem protection.

• Cryosphere Vulnerability:
  The mountain cryosphere, including glaciers, is one of the most sensitive components of the Earth system to climate change. Glaciers are melting at an increasing rate, leading to changes in water availability, timing, and quality. These changes are affecting the natural water cycle, increasing the risk of extreme weather events, and threatening both human and ecological systems.

• Global Water Stress:
  Up to 60% of the world's fresh water originates from mountain regions. However, 25 countries, home to one-quarter of the global population, face "extremely high" water stress annually. Over 4 billion people experience severe water scarcity for at least part of the year, with the greatest impact on rural populations.

• Climate Change Impacts:
  Climate change is causing increased seasonal variability, decreased snow cover, and more extreme rainfall events. These factors are contributing to the risk of floods, droughts, landslides, and sea-level rise, which have significant implications for downstream communities and ecosystems.

• Water Management Challenges:
  The report underscores the need for improved water management strategies, including climate change mitigation and adaptation, disaster risk reduction, and sustainable industrial and agricultural practices. It calls for a multilateral approach to address transnational issues related to water governance.

• Policy and Governance:
  Effective governance of mountain water resources requires international, regional, and local collaboration. The report highlights the importance of transboundary cooperation, especially in regions like the Hindu Kush-Himalaya, where water systems cross national borders.

• Sustainable Development Goals (SDGs):
  Progress towards SDG 6 (Clean Water and Sanitation) is off track. In 2022, 2.2 billion people lacked access to safely managed drinking water, and 3.5 billion lacked access to safely managed sanitation. The report stresses the need for better data collection, monitoring, and policy implementation to meet these goals.

Key Information

• Water Withdrawal by Sector:
  Agriculture accounts for 72% of global freshwater withdrawals, followed by industry (15%) and domestic use (13%). Lower-income countries use a larger proportion of their water for agricultural purposes.

• Glacier Retreat:
  The Andes have lost 30–50% of their glaciers since the 1980s. If no action is taken, glaciers in Mount Kenya, Rwenzori, and Kilimanjaro could disappear by 2040. The Hindu Kush-Karakoram-Himalayan system, known as the "Third Pole," could lose 50% of its glacier volume by 2100.

• Transboundary Cooperation:
  The Transboundary Water Cooperation Coalition was launched in 2022 to foster international collaboration in managing shared water resources such as aquifers, lakes, and river basins.

• Cryospheric Science Decade:
  2025 has been declared the International Year of Glaciers' Preservation, marking the start of the Decade of Action for Cryospheric Sciences (2025–2034), with UNESCO as the lead agency.

• Regional Perspectives:
  The report includes detailed analyses of mountain regions across Sub-Saharan Africa, Europe and Central Asia, Latin America and the Caribbean, Asia and the Pacific, and the Arab region, highlighting the unique challenges and opportunities in each area.

• Knowledge and Capacity Building:
  There are significant data and knowledge gaps in mountain regions, especially regarding the cryosphere. The report advocates for the integration of Indigenous, gendered, and local knowledge into scientific research and policy development. It also emphasizes the importance of enhancing local capacity and improving information-sharing systems.

• Solutions and Responses:
  The report outlines various responses, including sustainable agriculture practices, hydropower development, disaster risk reduction strategies, and ecosystem restoration projects. Examples include the Honghe Hani rice terraces system, Glacier Lake Outburst Flood (GLOF) management in Peru, and community-based water supply systems.

Conclusion

The report concludes that mountains are not only essential for water supply but also for the broader achievement of the 2030 Agenda for Sustainable Development. It calls for collective and rapid action at all levels – local, national, and international – to protect these fragile water systems and ensure sustainable water management. The UNESCO World Water Assessment Programme (UNESCO WWAP) plays a central role in coordinating these efforts, providing scientific knowledge, and promoting international cooperation.

Key Recommendations

• Strengthen transboundary water governance.
• Invest in cryospheric science and data collection.
• Promote inclusive and sustainable industrial development.
• Enhance capacity-building and local knowledge integration.
• Improve monitoring and reporting systems for water-related data.
• Support ecosystem protection and land degradation neutrality initiatives in mountain regions.