There is approximately 1,385 billion cubic metres of water on planet Earth, of which only 2.5%, or 35 billion cubic metres, is fresh water.
In 2000, the annual global water usage was approximately 4,430,000 cubic metres, where roughly 2,100,000 cubic metres was used as potable water. With an annual growth rate of approximately 80 million people on Earth, scientists estimate that global water usage will be set to rise to 5,240,000 cubic metres by the year 2025.
When looking at which countries use the most water per capita, USA, Canada, Australia and various Middle East countries rank amongst the highest with an average consumption of between 1,000-5,000 cubic metres of water per person, per year.
Human consumption and potable water only account for roughly 8% of the annual usage, while industrial use accounts for 22% and Agriculture for a whopping 70%.
To put things in perspective over why agriculture utilises such a high rate of annual fresh water, we can look at the following stats supplied by Waterfootprint.org:
- 2,500 litres of water = 1kg rice
- 10,000 litres of water = 1kg cotton
- 1,800 litres of water = 1kg of sugar cane
- 300 litres of water = 1 litre of beer
- 15,400 litres of water = 1kg of beef
- 1,600 litres of water = 1kg of wheat bread
It’s evident from the statistics above that one of the greatest influences on the overall usage of water is human consumption, where the production of meat products and clothing rank amongst the highest of water-reliant agricultural industries.
In 2003, the two global regions with the highest expanse of irrigated land were Asia and the North + Central Americas with 193,890 and 31,264 thousand hectares respectively.
One of the reasons for the high level of irrigation used in Central Asia is due to the type of land being cultured, along with the main agricultural focus. The 3 largest types of agriculture are Wheat, Cotton and Livestock and the land is mostly arid and mountainous, which calls for a higher degree of irrigation in order to affect suitable output.
Given the high degree of people who live in primarily rural settings across Asia (Upwards of 60% in all the former Soviet Central Asian states), their agrarian nature means that there is, besides commercial farming, also a high dependence on subsistence farming, which of course exacerbates the demand for water.
In order to balance out the scale between the global supply and demand of water, there needs to be an effective change in strategy when it comes to farming methods specifically. A type of futuristic farming method which has been proposed for urban areas is that of Vertical Farming. Not only does this ensure that natural land masses and forests can be maintained, it could also provide an inherent solution to over-irrigation as it is a controlled ecological system.
Image supplied by Jenn Durfey
- A reference source to the idea of using Vertical Farming as means to replace current farming methods and using farming in urban settings.
This article was written by ScribeZA. When looking at conservation of water in the home, you may be surprised to know that with good quality plumbed water coolers, you will be drinking less water than you would if it was straight from the tap, and it is chilled and filtered too!