Feeling thirsty?
You’re not the only one…
The world is becoming more concerned around its supply of water and the possibility of draught as a combination of a hotter climate and a growing global population
But how much water is there on Earth?
There is actually A LOT of water on this planet
71% of the Earth’s surface is made up of water, 96.5% of this being held in Oceans. The remainder is found in water vapor, rivers, lakes, icecaps, glaciers, in the ground as soil moisture, aquifers, reservoirs and even in all living things
There is 1.35 billion cubic kilometres (km³) of water on Earth (including Oceans), however of this:
- only 2.5% of this is fresh water (35 million km³) and can be used for human consumption
- and of this 35m km³, 69% is stored in glaciers and the ice caps and so not easily accessible (24m km³)
- plus, a further 30% of this fresh water is stored underground and not used directly by humans¹ (10.5m km³)
- overall, only 0.3% of global fresh water (93k km³) is surface water - fresh water such as in rivers and lakes, which are immediately available for human consumption
Despite 71% of the Earth’s surface being water, only 3.5% of this is fresh water and 0.3% of fresh water is immediately available for human consumption
So how much water do people use?
Global human consumption of fresh water is 4.3 billion km³ per year (4.3 e²¹ litres) - with the 93 km³ of fresh water mentioned above being re-used multiple times over the course of a year²
At least 70% of this used for Agriculture, including drinking water for animals and the water required to grow crops and animal feed, for example:
- Over 100 litres of water is required per dairy cow per day (a figure that can rise to 170 litres in hotter climates) - bear in mind that an average dairy cow will produce 36 litres of milk per day and live up to 6 years
- Although the amount of water required for cows not producing milk is much lower at between 24-50 litres per day
- Pigs require between 1-23 litres of water per day, depending on the stage in their development, while poultry needs up to 0.5 litres of water per day
- Cotton requires c. 22.5k litres of water for 1kg of output, while wheat and soybeans need just under 1k litres to produce 1kg of output
An average person needs 5 litres of drinking water per day to survive in a moderate climate with little activity
However, we use a lot more water on top of this. In Britain, the average household in 2021 used 335 litres per day (or 153 litres per person). Despite this, respondents to a 2020 survey thought they consumed less than 20 litres per day with only c. 10% believing they consumed over 140 litres - closer to the correct amount
And the British government now has set a target of reducing water consumption per person to 110 litres by 2030
And what is the impact of using too much water?
Droughts are becoming more common in the world because of climate change and wasted water is only going to exacerbate the issue:
- Back in 2018, the WHO estimated that 55 million people each year are affected by drought
- Since 2020, two thirds of India has experienced some form of drought (a landmass that covers 50 million people)
- The New Scientist Journal, Europe is currently experiencing its worst drought in 500 years
- Today, half of the US and England are both in drought
- The UN estimates that, by 2025, 30% of the world’s population will face water-related shortages and, by 2030, 700 million individuals will be displaced because of a lack of usable water
There are also a number of negative side effects of this water crisis:
- Water quality in developing countries is generally worse than elsewhere. As a result, 80% of all diseases in the developing world are water-related
- Plastic waters are often used as an efficient way to distribute better quality drinking water. However, it’s estimated that 500 million plastic water bottles are sold each year (which also has an environmental impact)
And while more needs to be done, there are some things that humans are doing to improve the situation. For example, there are at least 16,000 desalinisation plants that are active, or under construction, globally which gives humanity one additional option in providing more water for society³
Check out more of our GoodStats on the Environment and our planet:
Note¹: natural processes, including Agriculture will benefit from water underground
Note²: while most water consumption will come from these surface water sources, not all will. Plus there are other ways of storing and producing water such as reservoirs and de-salinisation plants
Note³: desalinisation plants are not without their problems. They produce a lot of brine as well as drinkable water, and require considerable electricity per gallon produced which is also harmful for the environment if not produced from renewable sources
Source: Economist; US Geological Survey; The World Counts; Comfy Living; EnviroTech; Claro Energy; Human League; Silver Lake Farms; World Health Organisation; Drought.gov; US Environmental Protection Agency; News Bigly; National Geographic
