In view of Jersey's ongoing water shortages it was interesting to read an article on the ongoing problem of water shortages around the globe.
The study, by Dutch researchers was published this week in the journal "Proceedings of the National Academy of Sciences". The study calculates the water footprint of each country from the perspective of consumption and production, based on information collected between 1996 and 2005.The study, from the University of Twente, analyzes the water footprint of all countries from the perspective of consumption and production.
This research is one of the first papers that analyzes the availability and use of water resources from a global perspective and international levels. So far these issues have been studied from a local or national view and may help better manage our limited water resources. This study calculates the water footprint of each nation, a measure that estimates the total volume of water consumed by man to produce goods and services.
Just three countries consume 38% of available water resources on the planet between them; China, India and the U.S. Consumption by these three countries amounts to 38% of total global water resources.
The authors conclude that the water footprint of a country is determined mainly by the different types of products consumed and the water footprint of those products. 92% of water goes to agriculture, with cereals, meat and milk production requiring the largest share of water. 27% of the total water used in the cultivation of food was used to cultivate cereals, 22% in meat production and 7% to produce milk.
They also measured the water footprint per capita. Although China and India are countries with a high total water footprint, spending per capita is lower than some other countries. In the case of Spain, each person uses an average of 2,461 cubic meters per year. In the U.S., a country with 289 million every citizen consumes each year 2,842 cubic meters. In India per capita consumption is 1,089 cubic meters while a Chinese citizen uses just cubic 1,071 meters.
The study identifies three components in the water footprint: blue, green and grey. The blue component refers to the consumption of water available on Earth's surface. The green, the consumption of water from the rain, which is particularly relevant in the production of crops. Finally, the grey trace is an indicator of water pollution. According to this study, China generates the most contaminated water.
The study also notes that during the period 1996-2005, approximately one fifth of the total water footprint is not related to domestic consumption but for export, which shows the importance of addressing the management of water resources from a global perspective .
Although at present the water footprint of China is largely domestic, rapid development and increased water consumption, suggest that it is likely that more and more dependent on external water resources.
The authors of this study say it is crucial that countries where water is scarce recognize the dependence on external sources and make their plans accordingly.
