Water stress evolution and redistribution pathways under global inequality in consumption

Area of Science:

• Environmental science
• Economics
• Global sustainability

Background:

• Global water stress is intensifying with rising consumption.
• Economic growth is strongly coupled with water consumption.
• Income inequality exacerbates water consumption imbalances and stress distribution.

Purpose of the Study:

• To analyze the relationship between consumption, economic growth, and water stress.
• To project future global water demand and stress.
• To identify water risk and redistribution potential using a dual indicator framework.

Main Methods:

• Consumption-based water footprint (CWF) accounting for 188 countries (1990-2020).
• Machine learning for future water demand and deficit projections.
• Weighted transfer contribution ratio (WTCR) and consumption-based water stress index (CWSI) framework.

Main Results:

• High-income countries reduce local water stress, while low-income countries face depletion and poverty.
• By 2090, global water demand may reach 10,653 km³ with a deficit of 5887 km³.
• >53% of the global population, primarily in Asia and Africa, will face high water stress.
• Redistribution capacity declines by 2090, threatening global water security.

Conclusions:

• Equitable burden sharing and trade restructuring are crucial for global water governance.
• High-income countries must increase environmental responsibility to achieve SDGs.
• Urgent action is needed to address structural imbalances in water consumption and stress.