A new global study warns that Earth is undergoing unprecedented freshwater loss. This endangers billions of people worldwide. Scientists analyzed over 22 years of satellite data from NASA and German missions GRACE and GRACE-FO. Findings revealed that terrestrial water storage is decreasing rapidly. The rate of loss also accelerated after a particular period. This indicates that there was a critical shift in global water balance trends.
Global Assessment of Freshwater Decline: Two-Decade Satellite Observations Reveal Accelerated Loss and Emerging Mega-Drying Regions
Researchers. H. A. Chandanpurkar et al. used satellite gravimetry data from 2022 to 2024 from the Gravity Recovery and Climate Experiment or GRACE and GRACE-FO missions. These satellites measure slight variations in the gravity field caused by changes in mass. The approach enabled the researchers to track terrestrial water storage from groundwater, rivers and lakes, soil moisture, and snow. The following are the important findings:
• Accelerating Freshwater Loss: Global terrestrial water storage has declined steadily since 2002. A major acceleration began around 2014-2015. This marks a hydrological tipping point where drying continents now outpace regions gaining water. It also demonstrates both climate-driven droughts and intensified human extraction.
•Formation of Mega-Drying Regions: Four vast mega-drying zones have emerged in the Northern Hemisphere. It expands each year by more than 800,000 square kilometers. These regions are continental in scale and have ecological and human impacts. They signify a shift from localized water issues to planet-wide hydrological imbalances.
•Groundwater as the Primary Driver: Around 68 percent of global freshwater loss stems from groundwater depletion. Excessive pumping for agriculture and urban needs depletes aquifers that took millennia to form. This water eventually flows to oceans, becomes unavailable for human use, and contributes to sea level rise.
•Contribution to Sea Level Rise: Groundwater loss contributes more to sea level rise than melting ice sheets from Greenland or Antarctica. Pumped and extracted freshwater entering the oceans accelerates the rise of sea levels across the globe. This finding essentially links land-based water depletion directly to coastal flooding risks.
•Substantial Impact to Humans: Nearly 75 percent of the global population, or around six billion people, lives in areas experiencing net freshwater loss. This scarcity threatens food production, public health, and livelihoods. Major river basins, including the Amazon, Ganges, and Mekong, are facing reduced flows, imperiling millions.
•Notable Geopolitical and Social Risks: Freshwater loss intensifies existing conflicts and may spark new geopolitical tensions. Historical examples show water shortages have contributed to crises in Syria, Ghana, and Ukraine. Similar patterns may emerge elsewhere as freshwater becomes a contested strategic resource.
Estimates suggest that hundreds of millions more could face severe scarcity by 2100. This could compound issues like climate adaptation and food security. Experts underscore that climate-driven changes are challenging to reverse, but groundwater overuse is addressable with immediate reforms. Recommendations include adopting efficient irrigation technologies, implementing strict governance frameworks, and promoting large-scale water recycling initiatives.
FURTHER READING AND REFERENCE
- Chandanpurkar, H. A., Famiglietti, J. S., Gopalan, K., Wiese, D. N., Wada, Y., Kakinuma, K., Reager, J. T., and Zhang, F. 2025. “Unprecedented Continental Drying, Shrinking Freshwater Availability, and Increasing Land Contributions to Sea Level Rise.” Science Advances. 11(30). DOI: 1126/sciadv.adx0298