New York: Asia, the continent that houses roughly half the world's population, will face a "high risk of severe water stress" by 2050 if the current environmental, economical and population growth persists, warns a new study.
The study points out that water shortages are not simply the results of climate change and environmental stress.
"It's not just a climate change issue. 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," said one of the researchers Adam Schlosser, a senior research scientist at Massachusetts Institute of Technology (MIT) in US.
"And climate, on top of that, can lead to substantial magnifications to those stresses," Schlosser added.
The findings, published in the journal PLOS One, showed that the median amounts of projected growth and climate change in the next 35 years in Asia would lead to about 1 billion more people becoming "water-stressed" compared to the present time.
To conduct the study, the scientists built upon an existing model developed previously at MIT, the Integrated Global Systems Model (IGSM), which contains probabilistic projections of population growth, economic expansion, climate, and carbon emissions from human activity.
They then linked the IGSM 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.
The study 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.
The IGSM model also allowed the team to look at how, under the same variables, scenarios change according to countries. This is particularly useful to come up with country-specific strategies, in order to avoid water stress.
"For China, it looks like industrial growth (has the greatest impact) as people get wealthier. In India, population growth has a huge effect. It varies by region," explained lead author Charle Fant, researcher at MIT.
Other variables, such as water supply networks into and out of the different areas, and the way population is distributed around said supplies should be examined, the researchers said.
"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," Schlosser said.