Water Scarcity Could Affect Three Billion More People, Global Warming And Rising Demand Risk To Global Supply

Water scarcity may affect three billion more people than previously thought by mid-century, as growing pollution and global warming are making river supplies "unsafe" for humans and wildlife.

Nitrogen Pollution

Water scarcity is a circumstance in which there is insufficient water to meet the demands of nature and society. Water scarcity is anticipated to worsen in the future, due in large part to climate and socioeconomic changes.

The new study, published in the journal Nature Communications, examined river basins all around the world, which are important sources of drinking water and hubs for urban and commercial activity.

According to the authors' computer modeling, the number of sub-basins-smaller units in river basins-facing acute water scarcity was twice as high as previously estimated in 2010, and the situation could worsen significantly in the future decades.

They estimate that 2,517 sub-basins around the world faced water scarcity in 2010, when nitrogen pollution's influence on water quality was taken into account, compared to only 984 in conventional quantity calculations.

That figure might climb to 3,061 by 2050, they discovered, affecting around 6.8 to 7.8 billion people-nearly three billion more than traditional projections.

According to co-author Benjamin Bodirsky, senior scientist at the Potsdam Institute for Climate Impact Research, the modeling of three distinct scenarios that changed pollution levels demonstrated that "we do have choices and can improve the situation".

However, he stated that even with the most optimistic projections, nitrogen pollution would remain at "substantial levels" in key agricultural regions such as Europe, China, and India.

"The deterioration of water access can be halted, and to some extent even reversed, by adopting more efficient fertilizer use as well as more vegetarian diets, and by connecting a larger proportion of the global population to water treatment facilities," Bodirsky said.

Human Activities

Water quality degradation caused by growing and newly developing pollutants has also become a major reason for limiting water's safe usage by nature and humans, exacerbating water scarcity issues.

For example, agricultural intensification and urbanization have introduced excessive contaminants into water bodies, including fertilizers, pathogens, plastics, and other chemicals.

Excess nitrogen inputs to aquatic ecosystems can have negative repercussions such as hazardous algal blooms, hypoxia, and fish mortality, complicating their usage for drinking water.

The UN's climate science panel has stated that around half of the world's population currently confronts acute water scarcity for at least one month per year and has warned that global warming consequences and rising demand are major threats to global supplies.

New research from scientists in Germany and the Netherlands has discovered that when dangerous nitrogen pollution is included, the number of regions classified as water-limited grows considerably.

"But I also see that water pollution is really becoming a more and more important issue that makes water unsafe to be used by nature and humans," lead author Mengru Wang, of Wageningen University & Research.

Human activities release significant amounts of nitrogen, bacteria, chemicals, and plastics into water systems.

Nitrogen from agricultural fertilizers, in particular, contributes to algae growth, which can clog waterways, endanger marine life, and degrade water quality.

The findings highlight the critical necessity of improving water quality in future water management plans for the Sustainable Development Goals.