NASA study finds freshwater depletion is 33% more severe than previously estimated

A study conducted by NASA and the University of Maryland reveals that the depletion of global freshwater reserves, particularly underground aquifers, is 33% more severe than previously estimated. Published in the ‘Proceedings of the National Academy of Sciences’, the research utilized advanced satellite gravity data from the GRACE and GRACE-FO missions to analyze terrestrial water storage trends between 2002 and 2025.

By employing higher spatial resolution through inter-satellite range data regressions, researchers identified 40 global hotspots where human activities significantly alter the hydrological cycle. Key drivers include agricultural irrigation, dam construction, deforestation, and rainwater use. During the study period, net water storage losses at these hotspots reached 3,122 gigatonnes, surpassing net gains of 2,432 gigatonnes.

The findings highlight that human activities represent a significant portion of large-scale water storage trends across five continents. Notable regions experiencing major losses include northern India, due to Himalayan glacier retreat and aquifer overexploitation, and the Brazilian highlands, impacted by extreme droughts.