Securing the world’s water supply is a significant challenge, and a new study from Stockholm University offers a unique perspective on quantifying the global risk of water scarcity. The traditional approach to water security focuses on rain falling on the earth’s surface and being stored in aquifers, lakes, and rivers. However, the study highlights the importance of considering the environmental conditions and governability of the areas where rain is produced. By examining the upwind origin of water, the researchers found that water risks are higher than previously expected.
Water supply is not just about what falls on the earth’s surface but also about the moisture evaporated from land or in the ocean traveling in the atmosphere before falling as rain. This upwind moisture, often overlooked in water availability assessments, plays a crucial role in water supply. The study looked at 379 hydrological basins worldwide and found that risks to water security significantly increase when considering the upwind origin of water. This approach revealed a near 50 percent increase in water requirements facing very high risk compared to the more traditional upstream focus.
Changes in land use can have significant impacts on downwind water availability, primarily due to a large amount of water being evaporated from plants. Agricultural development and deforestation in upwind areas can reduce the moisture vegetation provides, leading to decreased rainfall downwind and increased water security risks. For instance, countries like the Philippines, where most of the rain comes from the sea, may be less affected by land-use changes compared to inland countries like Niger, which rely on neighboring countries for moisture. Political factors such as environmental management and regulations in upwind areas can affect water safety in downwind regions.
The study emphasizes the importance of environmental regulation from an upwind perspective, as the lack of governability and environmental performance in a country upwind can impact the water supply of countries downstream. This highlights the codependence between upstream/downwind and downstream/upwind countries, emphasizing the interconnectedness of all water sources. It is crucial for countries to not only focus on managing their water resources internally but also consider how neighboring countries’ actions can affect their water supply.
The researchers hope that their findings can guide cooperation strategies and efforts to mitigate water-related tensions caused by atmospheric water flows in transboundary decision-making and water governance frameworks. International cooperation is essential to effectively manage upwind moisture sources and address the interconnected nature of water supply. By understanding the dependency between countries and the impact of environmental conditions and governability on water security, countries can work together to secure the world’s water supply and ensure sustainable management of this critical resource.