The study by Hoekstra et al. (2012) addresses the growing concern of freshwater scarcity by developing a more accurate assessment of global water scarcity using blue water footprints (consumptive use of ground- and surface water flows) and monthly rather than annual values. The authors analyzed 405 river basins from 1996 to 2005, finding that 201 basins with 2.67 billion inhabitants experienced severe water scarcity at least one month per year. The ecological and economic impacts of increasing water scarcity are highlighted, such as complete desiccation, aquatic biodiversity loss, and economic disruption in basins like the Rio Grande, Indus, and Murray-Darling. The study defines blue water scarcity as the ratio of the blue water footprint to the blue water available, accounting for environmental flow requirements. It provides a detailed monthly assessment of water scarcity, which is crucial for understanding when and where water consumption exceeds availability. The findings underscore the critical nature of water shortages globally and suggest that investments in water efficiency and productivity are necessary to prevent severe water stress.The study by Hoekstra et al. (2012) addresses the growing concern of freshwater scarcity by developing a more accurate assessment of global water scarcity using blue water footprints (consumptive use of ground- and surface water flows) and monthly rather than annual values. The authors analyzed 405 river basins from 1996 to 2005, finding that 201 basins with 2.67 billion inhabitants experienced severe water scarcity at least one month per year. The ecological and economic impacts of increasing water scarcity are highlighted, such as complete desiccation, aquatic biodiversity loss, and economic disruption in basins like the Rio Grande, Indus, and Murray-Darling. The study defines blue water scarcity as the ratio of the blue water footprint to the blue water available, accounting for environmental flow requirements. It provides a detailed monthly assessment of water scarcity, which is crucial for understanding when and where water consumption exceeds availability. The findings underscore the critical nature of water shortages globally and suggest that investments in water efficiency and productivity are necessary to prevent severe water stress.