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New Study Predicts Murky Future for Global Water Quality
While California’s four-year drought is forcing the most severe mandatory water restrictions in the state’s history, another water crisis is brewing that will affect far more people and a much greater territory – the planet at large.
According to a global study by the International Food Policy Research Institute (IFPRI) and Veolia, the world is on a path toward rapidly deteriorating water quality in many countries. The first-of-its-kind study indicates that up to 1 in 3 people will be exposed to a high risk of water pollution in 2050 from increased amounts of nitrogen and phosphorous. Up to 1 in 5 people will be exposed to a high risk of water pollution reflected by increased levels of biochemical oxygen demand (BOD).
“The global water crisis is not science fiction,” notes Ed Pinero, senior vice president, sustainability, Veolia North America. “The evidence of drought in the United States and in many parts of the world – lack of rain or snowfall, drying rivers and lakes, water shortages, and water restrictions – is real enough. Now we’re seeing how the impacts of high levels of organic pollutants can affect our health and society.”
Even using the most optimistic socio-economic models, water quality is projected to rapidly deteriorate over the next several decades which, in turn, will increase risks to human health, economic development and thousands of aquatic ecosystems in developed and developing economies alike. The new study follows previous substantial research conducted by the two organizations indicating that half of world’s population (52 percent of the global population or 4.8 billion people), approximately half (49 percent) of global grain production and 45 percent of total GDP ($63 trillion) will be at risk due to water stress by 2050 unless more sustainable water resource management practices are adopted.
“Globally, more people will be living in areas at a high risk of water pollution in 2050 due to increased loadings of pollutants,” explains Claudia Ringler, deputy division director of IFPRI’s Environment and Production Technology Division. “Our study examined the effects of increased nitrogen, phosphorous and BOD as human population, agriculture activity and economic development accelerates. We also examined potential impacts through the lens of established climate change models. While these nutrients occur naturally in the environment and, in fact, help sustain aquatic life, too much of a good thing is bad. The study’s results should be alarming to scientists, policy makers and citizens alike. Already, too many people are exposed to high risks associated with these pollutants.”
A major consequence of excessive nitrogen and phosphorous in water bodies is eutrophication, when algae grow faster than normal, killing other aquatic life by depleting oxygen. In addition, the presence of nitrogen-based compounds in drinking water can be harmful to human health. High levels of nitrates can have particularly harmful effects on infants through the so-called “blue-baby” syndrome. Prolonged intake of high levels of nitrates by adults can also lead to gastric problems.
Ringler says the study also demonstrates how water quality issues compound water quantity problems and amplify the need to simultaneously address both issues.
The global study uniquely links and layers socio-economic projections, climate change predictions, and projections for agricultural production with biophysical water quality modeling developed by IFPRI and Veolia, the world’s largest environmental and water company. Regions most affected by the studied pollutants (BOD, nitrogen and phosphorous) are densely populated, large agricultural production centers.
“The massive algal bloom in Lake Erie that triggered serious health concerns last year over safe drinking water is a very real example,” says Pinero. “When both water quantity and water quality are at risk, it’s a recipe for even greater challenges because poor water quality further reduces the amount of available water.”
Pinero points out that while nitrogen and phosphorous are already a serious problem in many waterways, the study indicates nitrogen and phosphorous loadings will increase substantially through 2050.
Nitrogen and phosphorous are naturally occurring nutrients that support the growth of algae and aquatic plants. When their levels are too high, both become pollutants and deplete oxygen from water, causing algae to grow faster than an ecosystem can handle, which produces elevated toxins and bacteria in water and creates compounds in drinking water that can be harmful to human health. A wide range of human activities, ranging from farming to wastewater treatment, contribute to the growing problem.
Biochemical oxygen demand is the amount of dissolved oxygen required by microorganisms to break down organic material in water. It measures the level of organic pollutants in water
“Most of us think that water pollution is the result of chemicals,” Pinero explains. “In the case of nitrogen and phosphorous, both are naturally occurring and appear to be almost harmless until there’s a shock to the system.”
Pinero says that as population grows and the quality of life improves, demand for water, food and sanitation will increase.
“These demands, especially with growing urbanization, will lead to increased discharges of nitrogen, phosphorus and elevated levels of BOD. A polluted water source is almost like having no water resource due to the high chemical, energy and treatment costs associated with making that water available and useable again. The good news is that there are many solutions stemming from technology, best practices and social behavior that give hope to minimizing the adverse impacts,” Pinero says.
Key findings include:
- Regions most affected include densely populated, large agricultural production centers. The largest levels of these pollutants are discharged in northern and eastern China, and parts of India, Pakistan and Bangladesh. The Midwestern United States, central Europe and central-eastern South America also generate high levels of nitrogen and phosphorous loads.
- The most rapid increases in exposure to pollutants will occur in low- and lower-middle income countries due to higher population and economic growth.
- By 2050, a drier climate change scenario – coupled with medium levels of income and population growth – projects that 1 in 3 people will be at high risk of nitrogen pollution (2.6 billion people or an increase of 172 percent); 1 in 3 people will be at high risk of phosphorous pollution (2.9 billion people or an increase of 129 percent); and 1 in 5 people will be at high risk of water pollution from BOD (1.6 billion people or an increase of 144 percent).
- Using the same data under a wetter climate change scenario produces similar results, with 1 in 4 people at high risk of nitrogen pollution, 1 in 3 people at high risk of phosphorous pollution, and 1 in 6 people at high risk of water pollution from BOD.
Solutions exist that can improve both social and ecological resilience. Greater adoption of sustainable agricultural methods can help – including enhanced nutrient use efficiency, phased out fertilizer subsidies, no-till or reduced tillage and other conservation measures, and closing the nutrient cycle.
Sustainable solutions also exist for cities and industry, including more aggressive investment in wastewater treatment, increased recycling and reuse, green infrastructure, the establishment of markets for nutrient credit trading, governance models based more on watersheds and less on traditional political borders, and improved home design to minimize pollution.