A new study shows how water pollution from intensified agriculture and untreated sewage could limit clean water supply
In the 2050s, one-third of the world’s rivers could be affected by water scarcity or be polluted by nitrogen, a new study by an international team of scientists has said.
The researchers, including from the Germany based Potsdam Institute for Climate Impact Research, assessed the scarcity of clean water under ongoing climate change and showed how water pollution from intensified agriculture and untreated sewage could limit clean water supply.
“While water scarcity is widely studied, the impact of future water pollution from human activities on the water supply is not yet fully understood,” the scientists who focused on nitrogen as a pollutant have said, in their study, published in Nature Communications.
Using a newly introduced Clean-Water Scarcity indicator, the scientists assessed future water quantity and quality in more than 10,000 global river sub-basins.
“In 2010, about 10% of the world’s sub-basins were classified as water-scarce when considering only water quantity, while 25% of the world’s sub-basins are affected by quantity & quality-induced scarcity,” the study said.
“The scenarios for 2050 show that pollution is disturbing the world’s clean water supply: In the worst-case scenario, about 30% of the world’s sub-basins could be affected by shortage of clean water in the year 2050, either in terms of having not enough water or the water being polluted,” the report said, adding that nutrients, such as “nitrogen and phosphorus, are vital for plant and animal growth, but their overabundance in water can lead to serious ecological damages.”
“When nitrogen concentrations in rivers are high, harmful algal blooms can disturb ecosystems and lead to clean-water scarcity in the future,” the scientist said.
In the study, the researchers say that increasing water scarcity could be stopped and the availability of clean water could be maintained and even reversed to some extent if more efficient fertilization practices as well as a more plant-based diet were introduced. The researchers have recommended connecting a larger share of the world population to sewage treatment.