Countries in Asia will face severe water shortages by 2050 if current environmental, demographic and economic trends remain unchanged. This is the conclusion that MIT scientists have reached, after running different simulations of future climatic scenarios in the region.
Published in the journal PLOS One, their study points out that water shortages are not simply the results of climate change and environmental stress. Other factors should be taken into account, if people are to have the best possible access to the precious natural resource.
"It's not just a climate change issue," co-author Adam Schlosser emphasises. "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."
The extent of the damages in Asia could indeed be very important. The scientists find that median amounts of projected growth and climate change in the next 35 years would lead to roughly 1 billion more people becoming "water-stressed", compared to today.
Different possible scenarios
To better understand how population growth and economic development interact with climate change, leading to water stress, the scientists used a model previously developed by the MIT, the Integrated Global Systems Model (IGSM).
The IGSM is based on projections of population growth, economic expansion, climate, and carbon emissions due to human activity. Keeping some variables constant, the scientists looked at different possible scenarios for 2050, in different Asian nations, including India and China.
They called one of their proposed scenarios the 'Just Growth' model, because they held climatic conditions constant and only evaluated the effects of economic and population growth. In the 'Just Climate' model, the researchers reversed the experiment, keeping growth constant. Finally, a model called 'Climate and Growth' completed the research, by looking at the impact of all factors taken together.
"This model gave us a unique ability to tease out the human and environmental factors leading to water shortages and to assess their relative significance", Schlosser says. He points out that a combination of all these factors can lead to the most severe water shortages, impacting millions of people.
Particularities between countries
The IGSM model allows researchers 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," lead author Charle Fant explains. "In India, population growth has a huge effect. It varies by region."
Study's authors say other variables should be examined, such as water supply networks into and out of the different areas, and the way population is distributed around said supplies. Further research by the team will also investigate to what extent changing water-use practices can have.
"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 concludes.