Where does it come from and where does it go?

 It takes 150 gallons of water to produce a single loaf of bread and almost 40,000 gallons to produce a car. In short, fresh water is essential to life on Earth, with agricultural, industrial and public use the three main areas of consumption. Looking at a simple map of the Earth it is clear that water is an abundant resource although only 2.5% of this is fresh water (fresh water is defined as water with less than 500 parts per million of dissolved salts) and fit for use in the previously mentioned activities. Most fresh water exists as glaciers and ice caps in the Antarctic and Arctic circles meaning it is unable to be exploited. Another 30% occurs as groundwater which is often hard to access. That means only roughly a quarter of fresh water used on Earth comes from groundwater sources. This leaves around 0.03% of the total global water supply available to humans at the surface. Of that number 69% of this exists as snow, ice and permafrost meaning only around 21% remains as lakes and rivers, the most obvious source of fresh water.

Currently, around 70% of globally accessible water is used for agriculture, although this increases in more arid areas, or countries where agriculture makes up a more significant proportion of the economy. The figure stands at around 20% for industry, although that rises to over 50% in industrialised nations.

The UN predicts a global population of 9.7 billion people by 2050. This, in turn will bring about a huge increase in demand for food, general products such as cars and clothes, and energy, all of which use vast amounts of water. However we are already exploiting our fresh water resources at a rate many may conceive as unsustainable, as it was shown in 2015 that 21 of the world’s largest 37 aquifers (a body of permeable rock that stores groundwater) were being depleted faster than they were naturally refilled by the hydrological cycle (Richey et al., 2015). Likewise, numerous large rivers such as the Colorado River and the Amu Darya (which used to feed the Aral Sea – now 10% of its original size) are no longer reaching the sea because their flow levels have been reduced so severely due to being over tapped.

Earth’s freshwater resources are unevenly distributed and currently almost one in 10 people ‘lack access to improved drinking water sources’. As the Earth's population increases and climate change continues to take effect, we can expect a growing challenge to humanity to ensure that developing countries and arid regions, where fresh water is economically and physically sparse, are able to access clean and safe water. 

This blog will aim to explore various issues regarding water scarcity, and the varying consequences of this problem as well as how it is tackled.