Economists and governments recognise that water is the one natural resource that can stop cities expanding and halt population growth in any given area. There is only a finite amount of fresh water on the planet, so just how much does it take to produce food, and what could happen if countries start to run out?
Imagine going to the store and facing sky high prices for basic fruit and vegetables, and not being able to buy the groceries you normally enjoy on a weekly basis. Looking at data from waterfootprint.org, fruits like tomatoes require 180 litres of water to produce a 1kg yield, whereas mangos use almost 10 times as much with a whopping 1,600 litres. Apples and pears sit down the middle using 700 and 860 litres respectively. Basics such as rice consumes 3,400 litres of water per kg, and daily stables like bread (from wheat) and milk (1 litre) use 1,300 and 1,000 litres of water respectively.
Although roughly 70% of the Earth’s surface is comprised of water, 96% is salt water held in the oceans. In fact, only 1% of the fresh water on earth is available for use. Waterfootprint.org report that many countries experience water shortages, including the driest on earth – Australia.
Water consumption by Australian agriculture
Australians are no strangers to water restrictions, but food demand will always remain, regardless of conditions. So, which crops use the most water in Australia? Here’s the top 10.
- Wheat – 44 x109: That’s 44,000,000,000m3 of water, which is 44% of the total water used in agriculture in Australia.
- Fodder crops – 12 x109 (12%)
- Barley – 12 x109 (12%)
- Sugar cane – 5.1 x109 (5%)
- Cotton – 4 x109 (4%)
- Rapeseed – 3.7 x109 (4%)
- Oats – 3 x109 (3%)
- Sorghum – 3 x109 (3%)
- Lupins (legumes) – 2.4 x109(2%)
- Rice – 4.1 x109 (1%)
These 10 crops use 90% of all the water used in agriculture in Australia. Most of the east coast receives enough rainfall in a given year to meet this demand, with the main problems to crop production being destruction from extreme weather. However, key systems across the country – such as the Eyre Lake River, the De Grey, Ashburton and Murchison River basins – all experience severe water shortages annually.
Why our water doesn’t always stay in the country
We may think that water can only move across the globe with the weather, but another powerful force is the import and export of crops. Let’s take the humble tomato – One Australian farm can produce over 250,000 tonnes of tomatoes per year. If they export 25% overseas, that’s 62,500 tonnes of tomatoes heading away from Aussie shores to countries like India, China and Japan. If 1kg of tomatoes is 94% water, that’s 58,750 tonnes of water leaving Australian shores from one farm in one year.
Importing and exporting water
Extrapolating this for all Australian farms would depend on the crop type, production amounts and how much was being exported. In 2012-2013 Australia exported $31.8 billion of food overseas.
Similarly, Australia imports some foodstuffs, the value of which was around $11.6 billion in 2012-2013. New Zealand is our largest provider of foodstuffs at 17.8% of all imports, meaning lots of fresh water is making the relatively short journey across the Tasman Sea.
Australians don’t only consume Australian grown food
As mentioned above, Australia imports over $11 billion in food from overseas per year, a figure that has grown by around $2.6 billion since 2007. Australia ranks 15th for global water use, the list below takes a look at the world’s top water consumers.
Top 10 water using countries (m3 of water per year)
- India – 1000×109 that’s 1,000,000,000,000 m3 of water per year
- China – 960×109
- North America – 800×109
- Brazil – 320 x109
- Indonesia – 310 x109
- Russia – 310 x109
- Nigeria – 190 x109
- Argentina – 170 x109
- Canada – 140 x109
- Thailand – 130 x109
Around 38% of the global water food print is accounted for by the top 3 countries. It’s also worth noting that Australia is 15th on the above list, using 99 x109 m3 of water per year.
What if these countries cannot produce the foods we rely on?
Three large countries we import goods from – India, Thailand, and China – currently experience water scarcity. If they were no longer able to supply Australia with these water intensive foods, it’s likely the prices of these goods would increase dramatically in Australian stores. This effect was seen at a local level when the price of bananas was expected to triple after cyclone Yasi in 2011. The supply of the product decreased, but demand was the same, driving prices up. Similarly, across the pond the UK saw prices rise by 30% in 2008 because droughts and high oil prices affected water-poor countries ability to produce food for export. Let’s take a closer look at these countries.
India is Australia’s 12th largest food supplier and the highest global user of water; each year areas of India have water shortages. River basins such as the Ganges to the north, and Krishna to the south average a significant water shortage throughout the year, with the Penner river basin being rated ‘severe’ by waterfootprint.org’s interactive water mapping tool.
Total food import value: $202.2 million USD, including:
- $37.2m rice
- $20.9m tea
- $16.5m coffee
- $ 2.21 m of coconuts, brazil nuts and cashews
China is our 3rd largest importer of foods, and ranks second when comparing global water use. However, there are water shortages to the west in the Tarm river basin, and to the north in the Yellow river basin. The Yongding He river basin suffers severe water shortages as a yearly average.
Total food import value: $750 million USD, including:
- $23.7m USD frozen vegetables
- $19.8m nuts
- $6.43m grapes
- $11.7m onions
- $2.43m apples and pears
- $10m processed tomatoes
Thailand is our 5th largest food importer, and the 10th largest user of water globally, but there are often water shortages to the north east of the country.
In 2013 Australia imported a total of $778 million USD, including:
- $74.2m of rice
- $5.36m of coconuts, brazil nuts and cashews
- $4.76m of frozen fruits and nuts
- $844k of bananas
- $1.64m of tropical fruits
With global populations expected to grow by 1 billion people by 2050 to reach 9.6 billion, water resources will only be put under increasing strain. So what would happen if countries were no longer able to produce the rice, apples, tomatoes and other staple goods to ship to Australia?
Projected outcomes of water shortages
Governments have predicted a range of outcomes should countries begin to suffer severe water shortages. The movement of goods aside, if a country cannot feed its own people due to a lack of water, social and economic problems could lie ahead. Disease from poor drinking water and famine from failing crops could cause social unrest, and neighboring countries that share a river basin could find themselves fighting over one of the world’s most basic, yet essential resources.
What could happen in Australia?
Assuming global warming doesn’t change the climate in Australia too severely and limit growing capabilities, the main change to food availability will likely come from the countries that already encounter water shortages, such as China, Thailand and India. Australian exports would likely increase to nations such as this, and imports could decrease. This would likely affect prices on Australian shores, pushing up the cost of food as demand outstrips supply.
How the global community could tackle this
One technology being developed is vapor compression distillation, that heats the water until it becomes vapor, then condenses it back into clean drinking water. However, the energy to heat the water needs to come from somewhere and heating water is one of the most power hungry activities we can perform.
Furthermore, the globe is commonly recorded as being 96.5% salt water, so turning some of this into fresh water through a desalination process is where most scientists hinge their hopes. This process forces the water through a membrane, splitting the water from the salt. Almost 16,000 desalination places are operating globally, turning 66.5 million cubic metres of salt water into fresh water for 300million people per day. However, the desalination process requires a lot of pressure, and is therefore a power hungry process that is expensive to run. Click here to watch a video on how desalination works.
What can be done now?
The BBC reports that in developing nation’s, 45 million cubic metres of fresh water is wasted through underground leaks every day. Closer to home, Australians use 99,000 gigalitres of water per year, which is the equivalent of 176.8 Sydney Harbour’s. Sensibly (and sustainably) managing our water use can be as simple as teaching others the importance of conserving one of earth’s most valuable resources.
The future of food production is an uncertain one. We may very well find that high water use crops, such as the humble tomato, may be affected early on. Let’s hope the price of a jar of salsa doesn’t one day equal a jar of caviar.