By Christian Mey-Boudoug
Global terrestrial water storage is estimated to have an annual variation capacity of around 1,000 cubic kilometers. This capacity, influenced by aggregated factors like precipitation, groundwater usage, and seasonal water fluctuations, globally varies as we stand on a side or another of the globe from areas of high concentrations to zones of lower concentration.
Fig.: Global Terrestrial Water Storage Trend
The map highlights global water changes observed by GRACE satellites from 2002 to 2016. Climate change drives ice-sheet loss in Greenland and glacier melt in Patagonia. Human activities, such as over-extraction of groundwater for agriculture, are depleting water resources in India, the Middle East, and Central Asia, including the Aral and Caspian Seas. Some regions, like South America and parts of Africa, display natural variability, with cycles of drought and recovery. Other areas show mixed impacts, with precipitation changes affected by both human activity and natural shifts.
Data from the Gravity Recovery and Climate Experiment (GRACE) and other climate projects have been crucial for monitoring these dynamics, particularly in predicting flood potential and understanding regional water stress levels over time. As a matter of fact, things like climatic variation and changes, added to huge human extractive activities, have over the years, significantly impacted terrestrial water storage and availability on the planet.
Fig.: Status and Evolution of Planetary Freshwater Boundaries
The map shows a significant regression in storage, as the world faces a water crisis, with the hydrological cycle disrupted, threatening sustainable development, climate stability, and ecosystems. This situation urges collective action to restore balance, ensure food security, and achieve the Sustainable Development Goals (SDGs). Decades of poor management have led to water scarcity, contamination, and overlooked “green water” – soil moisture crucial for rainfall – contributing to climate change, biodiversity loss, and human insecurity. The Global Commission on the Economics of Water (GCEW) calls for a new water economy, recognizing the hydrological cycle as a global common good. This involves valuing water, reforming policies, and preventing misuse. Inaction could severely impact human and economic health, with potential GDP losses of 8-15% by 2050 in water-stressed regions.
Solutioning global water risks also includes, not only efficient, equitable, and sustainable water management requires correct pricing, eliminating harmful subsidies, and proactive policies, but also integrating blue and green water governance, mobilizing sectors, and adopting a mission-driven approach are essential. The development of a Circular Water Economy would invite a revolution in the Food Systems, by enhancing water productivity and soil conservation, and adopting regenerative farming and plant-based diets. Other relevant solutions, including conserving green water and habitats, by protecting 30% of ecosystems and restoring 30% by 2030 would play in favor of a change of the current trend, and stabilize the water cycle.
Finally, thinking about a Global Water Pact to unify efforts, addressing the water crisis through multilateral cooperation and building on existing conventions. Inclusive dialogue with marginalized communities is crucial for sustainable outcomes. It would in the same run, be crucial to support more initiatives such as the “Fast Track Water Security” program, mobilizing resources for universal water access, irrigation, and climate resilience, and aiming to promote solutions for effective water management, transforming challenges into opportunities for growth, and a social contract centered on justice, equity and a resilient and sustainable future for all.