Water scarcity is entering a more dangerous phase—one in which the problem is no longer defined simply by how much water exists, but by whether that water is clean and cool enough for the people, farms, factories and power plants that depend on it. A new global assessment led by researchers at Utrecht University warns that, if current policies remain unchanged, almost two-thirds of the world’s population could face either insufficient water supplies or water that is too polluted to serve its intended purpose by the end of this century.
The study, published in npj Clean Water, is among the first to examine future water scarcity separately for major economic sectors while also accounting for water quality. Conventional assessments often compare water demand with the volume of water available in rivers, lakes and groundwater. But that approach can conceal a critical reality: a river may contain enough water in total, yet still fail to provide water suitable for drinking, irrigation, industrial processes or cooling power stations. The researchers therefore evaluated both water quantity and quality, revealing shortages that can be missed when the two are considered independently.
“Water scarcity involves so much more than just a shortage of water,” said principal investigator Gabriel Cárdenas Belleza. Different sectors operate with different water-quality requirements. Households generally need water that meets strict safety standards, while agriculture can sometimes use lower-quality water, depending on the crop and the contaminants involved. Industry may require water with specific chemical properties, and power plants need sufficiently cool water to remove heat from their systems. As climate change alters river temperatures and pollution levels, the same water source can become unusable for one sector while remaining technically available to another.
Climate change is expected to intensify these pressures through several interacting mechanisms. Rising temperatures increase evaporation from soils and reservoirs, alter rainfall patterns and make droughts more severe in many regions. At the same time, heat waves can warm rivers beyond the limits required for industrial and electricity-generation cooling. When river water becomes too warm, power plants and factories may be forced to reduce output or suspend operations, even if the river’s flow remains adequate. This creates a form of scarcity driven not by an empty waterway, but by water that no longer performs the function required of it.
The researchers also considered global socioeconomic trends, including population growth and economic development. These factors can increase demand for household water, food production, manufacturing and energy. Higher withdrawals can further degrade water quality because a smaller volume of water receives the same pollutant load. In a river with less flow, nutrients, chemicals and other contaminants become more concentrated. The result is a feedback loop: growing demand reduces available water, reduced flows worsen pollution concentrations, and deteriorating quality increases competition for the remaining clean supplies.
That competition is likely to become especially intense among households, agriculture, industry and energy producers. Agriculture is highly dependent on reliable water during growing seasons, but irrigation can also place heavy pressure on rivers and aquifers. Domestic users require safe supplies for drinking and sanitation, while industrial facilities may need water with carefully controlled temperatures and chemical characteristics. Power plants, meanwhile, can compete for the same rivers needed by other sectors, particularly during hot and dry periods when electricity demand rises because of cooling needs.
The most severe outlooks identified by the study are concentrated in sub-Saharan Africa and the Middle East. These regions already face limited access to clean water in many areas and are projected to experience substantial population growth. Under the researchers’ modeled scenarios, demand for domestic water in these regions could increase by as much as 1,225 percent. When the additional effects of declining water quality are included, the study estimates that the effective water shortage could rise to nearly 2,000 percent. These figures represent projected changes relative to the study’s baseline conditions, rather than a literal loss of 2,000 percent of today’s water supply, but they illustrate how quickly demand and quality pressures can amplify one another.
The picture is more complicated in wealthier regions such as the United States and Europe, where population growth is expected to level off over the long term. Slower population growth could limit or even reduce household water demand, potentially easing one component of scarcity. Yet the researchers caution that this does not make these regions immune. More frequent heat waves, lower freshwater availability and rising river temperatures could threaten power generation and industrial production. A region may therefore appear secure when judged by household demand alone while facing serious operational risks in its energy and manufacturing sectors.
The findings point toward a broad policy overhaul rather than isolated conservation campaigns. Governments may need to coordinate water management across borders, because rivers and aquifers frequently cross national boundaries and pollution can move downstream. Policies could include stronger controls on contaminants, investment in wastewater treatment and water reuse, improved monitoring of river temperatures, and planning systems that allocate water according to sector-specific quality requirements. The study also raises questions about whether industrial processes and energy systems should be redesigned to use less freshwater or tolerate warmer and lower-quality supplies. Without faster action, the researchers warn, future water crises will be determined not only by how much water remains, but by who can use it—and whether it is clean and cool enough when they need it.
Subject of Research: Not applicable
Article Title: Sector-specific clean water scarcity and competition under global change
News Publication Date: 10-Aug-2026
Web References: https://doi.org/10.1038/s41545-026-00608-0
References: Cárdenas Belleza et al., “Sector-specific clean water scarcity and competition under global change,” npj Clean Water, DOI: 10.1038/s41545-026-00608-0
Image Credits: Utrecht University/npj Clean Water
Keywords: water scarcity, water quality, climate change, clean water, global warming, drought, freshwater, agriculture, energy production, industrial water use, population growth, water policy, Utrecht University
