Aridity in Asia-Pacific: A Silent Slow Burn, Rising Visible Losses

December 8, 2025

Author

Nazneen Ahmed

UNDP Policy Advisor, UNDP Regional Bureau of Asia and the Pacific

Aridity is a long-term climatic condition of persistent dryness and it doesn’t make headlines the way cyclones or floods do. It creeps in quietly- less rain each season, drying soils, shrinking rivers, and landscapes losing their resilience year by year. It is measured by the Aridity Index (the ratio of rainfall to evaporation), with drylands defined as areas below a certain moisture threshold. Over 77% of Earth’s land became drier from 1991 to 2020 compared to the previous 30 years. Even places not traditionally seen as “dry” are beginning to show clear signs of moisture stress. Drylands already cover about 40.6% of the world’s land. The population living in drylands has doubled in the past three decades, to 2.3 billion, and projections show this could rise to 5 billion (nearly 40% of the global population) by 2100.

Aridity poses greater challenges than drought, leading to agriculture being undermined, land degradation, and increased insecurity. Unlike drought, which is temporary, aridity represents a long-term shift in the water balance, making recovery increasingly difficult. In Mongolia, for instance, rangelands that once supported nomadic herders are degrading at a rate far faster than in most other regions, with nearly three-quarters of the land now affected. Across northern China, vast dryland belts are expanding, contributing to more frequent sand and dust storms that cross provinces and borders. In Iran, the slow drying of wetlands like Hamoun has turned once-productive plains into major dust sources. These examples may seem different, but together they reveal a common story: aridity magnifies existing vulnerabilities, and when left unmanaged, it accelerates a cycle of land degradation, rural poverty, and environmental risk.

Countries in the region are responding with approaches, in many cases with UNDP’s active role. Mongolia is experimenting with community-led pasture management and large-scale tree planting to restore rangelands and stabilise soils. China is combining traditional land knowledge with innovation, such as using drought-resistant vegetation like liquorice to fix sand dunes while reducing water use. Iran is restoring wetlands and strengthening local governance so that communities can adapt to dwindling water sources.

Crucially, regional cooperation is emerging as a cornerstone of aridity response. Sandstorms do not stop at borders. In 2023, with UNDP facilitation, China and Mongolia inaugurated a joint Desertification Prevention and Control Centre in Ulaanbaatar. In West Asia, Iran is collaborating with Iraq and Afghanistan to restore shared wetlands and reduce dust pollution, demonstrating how common threats can foster South–South cooperation. And across the wider Asia-Pacific, countries are contributing to regional initiatives (such as the proposed Global Coalition on Rangelands and Pastoralists) to pool resources and advocate for the often-overlooked needs of dryland communities.

Technology is adding a new layer of complexity to aridity. On the one hand, the rapid growth of artificial intelligence and cloud services is creating water-intensive infrastructure, data centres that demand huge volumes of cooling water in places already facing scarcity. Today’s data centers consume an estimated 560 billion liters of water per year (a figure that could double by 2030). Much of this demand is concentrated in already water-scarce areas. On the other hand, technology is also giving countries new tools to manage aridity. AI-driven drought prediction models, remote sensing systems that track land degradation in real time, and precision irrigation that reduces water wastage all offer powerful ways to stay ahead of change. Enhanced remote sensing and machine learning models now predict sand and dust storms with over 80% accuracy a day in advance. In agriculture, which uses 70% of global freshwater, AI-driven precision irrigation is a game changer: by delivering the right amount of water exactly when and where needed, farmers have cut water usage by up to 30% while boosting yields by 20% in some pilots. The challenge is to ensure that technological progress alleviates pressure on water systems instead of intensifying it. Without careful planning for the expansion of AI, even cities that are traditionally rich in water could experience strained supplies.

This is why the upcoming UNCCD COP17 in 2026 in Mongolia is an important moment for the region. It offers a platform for Asia-Pacific countries to bring these experiences together, learn from one another, and shape a collective response. Mongolia’s presidency is already steering global attention toward rangelands, drylands, and the communities that depend on them. For countries that are only beginning to see the signs of aridity, COP17 is an opportunity to take stock of emerging risks, embed aridity into national plans, and secure the partnerships and financing needed to act early. For those already living with advanced aridity, it is a chance to share lessons, scale what works, and call for stronger regional cooperation on sand and dust storms, water governance, and land restoration.

Addressing aridity is ultimately about changing the rhythm of how we plan. Instead of responding to crises after they unfold, countries need to anticipate the slow changes beneath the surface, changes in soil structure, groundwater recharge, vegetation cover, and seasonal rainfall patterns. Early action, smarter use of technology, and a stronger role for nature-based solutions can help break the cycle of degradation. But no country can do this alone. Aridity crosses borders, and so must the solutions.