Is global water scarcity the next major humanitarian crisis?

How many people are already affected by water scarcity?

Water scarcity is not a future threat—it is a present crisis affecting billions. When only the amount of available water (quantity) is considered, about 30% of the world's population experiences severe water scarcity each year. But once water quality is factored in—things like pollution from sewage, industrial waste, and agricultural runoff—that figure jumps to 40% [1]. That means roughly 3.2 billion people currently live with water that is either too scarce or too contaminated to meet their needs. The problem is especially acute in eastern China and India, where polluted return flows from farms and factories make a bad situation worse [1].

The crisis is not limited to developing nations. A 2024 analysis notes that almost four billion people face severe water scarcity worldwide, and this cuts across rich and poor countries alike [2]. In the United States, Brazil, and North and North-Central Africa, water shortages are already causing economic and social strain. India serves as a stark example: its per-capita water availability has dropped nearly fourfold since 1951, even as its population quadrupled to 1.46 billion [2]. The country now withdraws more freshwater than any other nation—2.5 trillion cubic meters per year—and its aquifers are dangerously depleted.

Will water scarcity get worse by 2050?

Yes, and the numbers are sobering. A 2021 study projected that the global urban population facing water scarcity will increase from 933 million in 2016 to between 1.7 and 2.4 billion by 2050—that is one-third to nearly half of all city dwellers [7]. The number of large cities exposed to water scarcity is expected to grow from 193 to as many as 284, including 10 to 20 megacities. India will be hit hardest: its water-scarce urban population could swell by 153 to 422 million people [7].

Climate change is a major driver. It degrades rainfall patterns, melts glaciers that feed rivers, and increases evaporation from reservoirs [2]. At the same time, population growth and rising living standards push demand higher. In agriculture, which uses the bulk of freshwater, a 2021 study found that 22% of the world's river basins already face agricultural water scarcity when both rainwater (green water) and surface/groundwater (blue water) are accounted for—nearly three times the 8% identified when only blue water is considered [8]. This scarcity has been intensifying over the past four decades, especially in Asia and Africa, due to expanding cropland and competing water withdrawals by other sectors.

What does water scarcity actually mean for people's lives?

Water scarcity is not just about dry taps—it is a direct threat to health, security, and stability. When clean water is unavailable, people turn to contaminated sources, and waterborne diseases explode. In Afghanistan, a 2022 cholera outbreak linked to poor water and sanitation infrastructure caused over 150,000 suspected cases and 55 deaths in just a few months [3]. The World Health Organization reported that cholera outbreaks occurred in 26 countries in 2022, the highest number on record, with Afghanistan bearing the heaviest burden in Asia [3]. The disease thrives in warm, polluted water—conditions that become more common as droughts and floods intensify.

Groundwater quality is also deteriorating. In the Horn of Africa, a 2023 study found that about 11.6 million people—7% of the region's population—rely on groundwater with hazardous salinity levels (above 1500 microsiemens per centimeter) [4]. This includes 400,000 infants and half a million pregnant women. In Somalia, the situation is dire: roughly 50% of the population (5 million people) may be drinking water with unsafe salt levels [4]. High salinity in drinking water is linked to infant mortality and infrastructure damage.

Water scarcity can also fuel conflict. A 2022 analysis of left-wing terrorist groups in Colombia, Peru, and India found that climate-driven hazards like drought, famine, and water scarcity are exploited by organizations to recruit members and incite violence [6]. Competition over shrinking resources creates grievances that extremist groups weaponize, turning an environmental crisis into a security crisis.

Can technology and policy turn the tide?

Technology can help, but it is not a silver bullet. Expanding desalination and treated wastewater reuse could significantly reduce water scarcity. A 2021 study estimated that increasing global desalination capacity from 2.9 to 13.6 billion cubic meters per month, and treated wastewater reuse from 1.6 to 4.0 billion cubic meters per month, would strongly reduce water scarcity levels, especially in Asia [1]. However, these solutions come with trade-offs: desalination produces brine waste, consumes large amounts of energy, and is expensive. Newer technologies like capacitive deionization using carbon nanofoam electrodes show promise for smaller-scale, energy-efficient desalination of brackish water, but are still at the bench-top stage [5].

Policy changes are equally critical. In India, steps like interlinking rivers, harvesting rainwater, improving irrigation methods, and changing crop patterns could reduce groundwater depletion [2]. But the key factors, as one 2024 analysis bluntly states, are 'political will and economic realities' [2]. Without them, even the best technologies will not reach the people who need them most. The good news is that more than two-thirds of water-scarce cities could relieve their shortages through infrastructure investment—but the environmental costs of large-scale projects must be carefully managed [7].

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