How do people live?
The population of the earth has increased exponentially over the past centuries due to the medical and technical progress brought about by industrialisation. Prior to the massive implementation of technology and innovation, people had to make a living from primary production or craftsmanship and trade. Due to the low standard of hygienic and medical knowledge, people rarely reached a great age. It was only with the increase in living standards, part of which was due to access to flowing fresh water, that the life expectancy and thus the population size was able to increase massively.
First of all, it was the cities which grew into metropolitan areas during the industrialization period providing new jobs in the cities. Improved medical care, and access to education became easier. Nowadays, cities are connected with rural areas via a solid infrastructural network, and education, streets, water and electricity reach the entire population.
What do we need water for?
The increase in life expectancy and the strong population growth since the end of the 18th century was due in large part to access to fresh water. This is because water plays an important role for humans: it is used for producing energy, for watering fields and for transportation. The most important function of water is, however, that it quenches our thirst and that it facilitates hygiene.
We have to drink around 2.5 litres of fluid a day to ensure that we stay hydrated. This drinking water is taken from our natural water cycle. In Germany, around two thirds of our drinking water comes from groundwater. The rest originates from springs, rivers, and lakes. In areas of the world with lower rainfall, groundwater is often not regenerated as fast as it is used up for drinking water. In these places, people suffer from water shortages and have to develop new methods of producing water. One of these methods is the desalination of seawater, which is very costly. The water which we use in our homes and industries eventually ends up back in the water cycle through the sewage system.
Water is also used for recreation: many people spend time relaxing at the coast and on the beach, or at lakes and other bodies of water. Water seems to have a relaxing effect on us and can even benefit our health – after all, many health resorts are situated near bodies of water.
How does water usage put people and the environment to the test?
Rivers slowly dry out when large amounts of water are taken from them for water provision in areas of low rainfall. An example of this is the Dead Sea: it receives its freshwater from the Jordan, a large river in Jordan. As many people use the water from the Jordan for drinking water and for the watering of farmland and fields, the Jordan has been dried up almost completely. The reduced freshwater influx and the high precipitation in this arid region resulted in a slat contents of the Dead Sea which is almost ten times higher than other seas. These changes represent a challenge not just for people, but also for plants and animals. The people in the region are arguing about the low water supplies of the Jordan, while the creatures living in the water have to adapt to the high concentrations of salt in the Dead Sea in order to survive.
At the same time, many bodies of water are heavily polluted. The waste water from sewage treatment plants shows traces of medications and household chemicals, which are then washed into the rivers. Rubbish also often manages to find its way into our waterbodies. Special wastes such as medication, chemical wastes but even wastewater from sewage treatment plants affect the health of water organisms. Among the pollutants, even plastic, while being inert, is dangerous for water dwellers, as it can take up to 400 years to completely degrade. In this time, many animals suffocate, either when they accidentally swallow small pieces of plastic, or when they get caught in or on them. The more people live together, the more rubbish they create. To make sure that rubbish and its by-products does not end up in our waterways, it is important to dispose it properly and to limit our use of its origins.