There's no life without water, from elephants and humans to bacteria. We must consume 2.5 liters of water from food and beverage to remain healthy. Water is also necessary for livestock and farming, the means for producing our food. Our planet could be covered by a global ocean 2.5 km (1.5 mi) deep if even. But most of it is salty seawater. A human drinking seawater would die from dehydration. Crops cannot be irrigated with this water and if used in industry, it quickly oxidizes any machinery. Only 3% of the Earth's water is freshwater, but 99% of it is stored in ice. Even this 1%, if uniformly distributed and rationally used, would be enough to sustain a human population two-three times larger than the current one.
In US, the consumption is over 350 liters of water daily, as much as for filling 2.5 bath tubs, used for showering, in water taps or flushing toilets. In developed countries, water is at the reach of a tap and always available, while in most Africa, the closest water source can be a river kilometers away and coming back with a big recipient of water can take an entire morning. This water must be filtered to eliminate parasites and used for drinking, domestic use, and bathing. Clothes are washed in the river. While Asia contains 36% of the world's lakes and rivers, it harbors 60% of the world's population. Instead, the Amazon river detains 15% of the water contained by the world's rivers, still only 0.4% of the world's population use its waters.
Earth's climates also have variable dry periods and people can "work" on it. Deforestation, excessive agriculture and grazing provoke desertification. The light reflected into the atmosphere increases and more heat disperses the rain-bringing clouds. That's why 84% of the Greek territory is now menaced by desertification and 8% of it is already
dry. A great part of the forests' rainfall is water evaporated from the vegetation. When trees and bushes are cut, water amounts forming the clouds decrease.
The naval traffic can influence weather on coastal areas. The cloud layer has turned thinner on coastal areas and thicker above the densely navigated maritime ways. The ash particles from the smoke of the ships act like condensation nuclei, leading to the formation of more water droplets. And in the 50 years, the fuel burned by the ships has increased four times.
Indeed, the water crisis is getting more and more severe. The lack of water menaces the economy and people's health in 80 countries.
Developed countries can build dams, use expensive technologies to recycle water or even desalinize seawater, while poor countries must choose between rationalizing water, thus impeding economical development and decreasing food production and reusing the untreated water, which increases disease spread. And water requirements are increasing everywhere, also connected with the growth of the population. By 1990, 1.2 billion people were exposed to disease contaminated water and annually 3.4 million persons die because of these diseases. In the last 100 years, the water consumption doubled per capita and in ten years it could be doubled again, whilst the available water amount per capita is twice smaller than 50 years ago.
Today, 20 % of the world's population does not have access to drinking water and 40 % does not have access to sanitation.
By 2050, developing countries could move world's population to the number of 9.3 billion. 4.2 billion people won't reach their water and food requirements. Already 2.1 billion people experience this. What's worse, people from poor countries are more directly connected to the natural sources of land, wood and water. 1.2 billion people worldwide suffer from malnutrition: they get enough calories, but lack essential vitamins and minerals. Megacities growth in the developing countries occurred explosively and in a chaotic manner, crowding poor people in huts lacking paid salubrization and hygienic conditions. These people must buy water, often dirty and always expensive.
More people need more food and more water to agriculture competes with the requirements of the industry and people. Moreover, the demographic boom occurs in the developing countries, where in most cases, water is also scarce. Over 50% of the world's rivers are now drought or polluted. One factor is the wrong use of water and soil. The wastewater from industrial and municipal use, damped in the rivers worldwide represents over 450 cubic kilometers. Many rivers are contaminated from springs to mouth. In developing countries, the drain off of the untreated waste waters contaminates almost all rivers. 80% of the Russian rivers present risky levels of bacterial and viral load.
Today, the healthiest rivers are considered Amazon and Congo (the world's largest) because of the very few industrial centers located on their banks. The table waters and rivers in developed countries are often poisoned with toxic chemicals coming from farm fertilizers. Almost all coastal countries discharge in shallow waters untreated waste water, polluting severely the beaches. All that is thrown, washed or swept in the coastal cities goes directly into the sea, untreated, like oils and car liquids, as well as pet feces. Bathing close to those sewage channels increases the risk of fever, vomits, respiratory infections and ear pain by 50% as compared to those doing it at least 360 m (1,200 ft) away.
The reverse too can be harmful. A healthy beach accumulates daily twice as many organic marine remains, like wood, algae, grass, and even dead animals. Small crustaceans decompose these dead organic materials, which after that work as a binding material for the sand. Cleaning the beach leads to the decrease in the number of crustaceans, and shorebirds feeding on them are this way gone. Experiments revealed that estrogen mimicking chemicals from wastewater cause reproductive issues in fish and amphibians. At each 8 seconds, a child dies because of a disease transmitted through the infected water.
In developing countries, 80% of the infections are spread through water. Water transmitted pathogens like those causing amoeba-linked diarrhea, cholera and typhoid fever (mostly on the tropics) kill 25 million persons each year. But in 1993, 400,000 persons from Milwaukee (Wisconsin, US) got sick after consuming tap water contaminated with a microbe resistant to chlorine. In the same year, in the sewers of Washington, New York and Cabool (Missouri) dangerous microbes were found. The water crisis leads to tensioned situations and conflicts. A major issue is the distribution of water coming from the great rivers. 40% of the world population lives on rivers crossing several countries, like Brahmaputra, Indus, Mekong, Niger, Nile and Tiger and each country wants to exploit at maximum their water.
The water crisis affects also the wildlife. In Somalia, baboons and hyenas attack villages affected by drought. In the scrimmages for water, many baboons died and shepherds were hurt. These large monkeys position themselves at road crosses or bridges to attack trucks loaded with foods for the local markets, being able to steal water melons or clusters of bananas.