More than half the world’s population lives under conditions of severe water scarcity, according to a research published Friday in Science Advances.
The paper states that four billion people around the globe face this problem, at least, one month of the year, including 1 billion living in India and 0.9 billion living in China.
The Earth has enough total water for all needs. However, scientists involved in the research explained that the main problem is that freshwater is not always available in every region where it is needed, when it is needed, because of disadvantaged physical location or deficiencies in water use in terms of social or economic implications.
Water consumption is highest when its availability is lowest. Scarcity tends to be most severe in areas with either high population density, such as Great London area, or the existence of an intensely irrigated agriculture, such as High Plains in the United States, India, and eastern China.
One might think that water is obviously scarce in every desert, but study authors wrote that the problem is worse in the Arabian Desert because of the irrigation intensity and higher population density.
The research was conducted by Mesfin Mekonnen and Arjen Hoekstra of the University of Twente in the Netherlands. They used a very detailed global model to study the availability of “blue water”, which includes surface and underground freshwater, compared with the demand for it from agriculture, businesses and individual home needs.
Hoekstra said that agriculture is the leading source of human water demand, followed by industry. Human household’s needs are the lowest, with about 1 to 4 percent of the total, the author stated.
The model involves climatic and ecological factors, as well as others that could cause the depletion of rivers and lakes. The authors remarked that previous studies had not deeply examined the phenomenon, since they only examined it on an annual basis and did not take into account the variation of water scarcity levels within months.
Those prior studies had found that 1.7 to 3.1 billion people around the world face severe water scarcity, compared with the current 4, which includes 120 living in the United States, particularly in California and other western states.
When talking about water scarcity, it is important to emphasize that people will not suddenly go without drinking water, Hoekstra stressed. He said that the main impact of water shortages go upon agricultural systems and farmers, meaning that food security results threatened.
The study points at which regions are most likely to face food crisis if they get alarmingly low amounts of rainfall, entering into a long period of drought. Should this happen, people living under extreme poverty would be the most affected because rich societies would be able to buy their vital resources from elsewhere. “If it’s a poor country, then the country will be really in trouble, and people will have no food,” Hoekstra commented.
Source: Science Advances