AsianScientist (Apr. 5, 2016) – Economic and population growth on top of climate change could lead to serious water shortages across a broad swath of Asia by the year 2050, according to a study by scientists at Massachusetts Institute of Technology (MIT). Their paper was published in PLOS ONE.
The study deploys detailed modeling to produce what the researchers believe is a full range of scenarios involving water availability and use in the future. The authors conclude there is a “high risk of severe water stress” in much of an area that is home to roughly half the world’s population.
Having run a large number of simulations of future scenarios, the researchers find that the median amounts of projected growth and climate change in the next 35 years in Asia would lead to about one billion more people becoming ‘water-stressed’ compared to today.
And while climate change is expected to have serious effects on the water supply in many parts of the world, the study underscores the extent to which industrial expansion and population growth may by themselves exacerbate water-access problems.
“It’s not just a climate change issue,” says Dr. Adam Schlosser, a senior research scientist and co-author of the study.
“We simply cannot ignore that economic and population growth in society can have a very strong influence on our demand for resources and how we manage them. And climate, on top of that, can lead to substantial magnifications to those stresses.”
To conduct the study, the scientists built upon an existing model which contains probabilistic projections of population growth, economic expansion, climate, and carbon emissions from human activity. They then linked the model to detailed models of water use for a large portion of Asia encompassing China, India and many smaller nations.
The scientists then ran an extensive series of repeated projections using varying conditions. In what they call the “Just Growth” scenario, they held climate conditions constant and evaluated the effects of economic and population growth on the water supply.
In an alternate “Just Climate” scenario, the scientists held growth constant and evaluated climate-change effects alone. And in a “Climate and Growth” scenario, they studied the impact of rising economic activity, growing populations and climate change.
Approaching it this way gave the researchers a “unique ability to tease out the human [economic] and environmental” factors leading to water shortages and to assess their relative significance, Schlosser said.
This kind of modeling also allowed the group to assess some of the particular factors that affect the different countries in the region to varying extents.
“For China, it looks like industrial growth [has the greatest impact] as people get wealthier,” said lead author, Dr. Charles Fant. “In India, population growth has a huge effect. It varies by region.”
The researchers also emphasize that evaluating the future of any area’s water supply is not as simple as adding the effects of economic growth and climate change, and it depends on the networked water supply into and out of that area.
Building on this work, the research team is continuing to work on related projects, including one on the effects of mitigation on water shortages. While those studies are as yet incomplete, the researchers say that changing water-use practices can have significant effects.
“We are assessing the extent to which climate mitigation and adaptation practices—such as more efficient irrigation technologies—can reduce the future risk of nations under high water stress,” said Schlosser. “Our preliminary findings indicate strong cases for effective actions and measures to reduce risk.”
The article can be found at: Fant et al. (2016) Projections of Water Stress Based on an Ensemble of Socioeconomic Growth and Climate Change Scenarios: A Case Study in Asia.
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Source: MIT; Photo: Shutterstock.
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