Two billion people live in water scarcity countries, and 1.6 billion people do not have access to it due to a lack of infrastructure. Changing this situation requires an investment of approximately $ 1.7 trillion, according to the authors of the UN report published on the occasion of World Water Day celebrated on Monday.
Worldwide, 12 percent. fresh water is used for municipal purposes, 19 percent. is used in industry, and 69 percent. in agriculture. Global consumption has increased sixfold in the last 100 years due to population growth, economic development and changing consumption patterns, and continues to grow at around 1%. annually.
According to the United Nations, which recognized access to water as a human right in 2010, one of the most important changes required is to rationalize the way water is used to produce food. One of the problems with this is that currently 30 percent. of the largest groundwater systems are depleted, incl. in India, Pakistan, the Arabian Peninsula and North Africa, mainly by abstraction of irrigation water.
Inefficiency in agricultural water use is also causing environmental degradation, reduced river flows, degradation of wildlife habitats and environmental pollution.
Another required change is the rationalization of daily consumption. An example is the consequence of the drought-induced water crisis in Cape Town, South Africa in 2017-2018. When the authorities of a city with 4 million inhabitants announced the closing date of water supply stations due to lack of water, its consumption dropped by more than half in a few months: from 1.2 billion to 516 million liters per day. This effect was achieved thanks to the introduction of consumption restrictions, reducing the pressure in taps or the ban on using water to wash cars or fill pools.
There is still much work to be done in the area of wastewater treatment. Ok. 60 percent Domestic wastewater (from households) is safely treated, but only in high and middle income countries. It is estimated that only 8 percent. Industrial and municipal wastewater in low-income countries undergoes any treatment. Worldwide, about 80 percent. all industrial and municipal wastewater is released into the environment without prior treatment, with detrimental effects on human health and ecosystems.
The UN report also highlights the role of diet, as meat production uses the most water of any commonly consumed food. In the case of beef, it is even 15 thousand. liters per kilogram, compared to 4.5 thousand. liters needed to produce the same amount of legumes. The problem is more and more important as meat consumption increases with the increasing wealth of the world's societies.
The Food and Agriculture Organization of the United Nations (FAO) recommends the introduction of the so-called sustainable diets, that is, diets that are healthy, have low environmental impact, are affordable and culturally acceptable. At the same time, they assume a limited consumption of meat, sugars and highly processed products, which could reduce the use of water for food production by about 20%. compared to the currently popular diets.
An alternative method of obtaining water is desalination of water, mainly sea water, but also groundwater with increased salinity, which doubled in the years 2007-2017. Approximately 100 million cubic meters of desalinated water are currently produced daily, a quarter of which is for Saudi Arabia and the United Arab Emirates, and half for the entire Middle East and North Africa.
However, this method has three main disadvantages: it is expensive, energy-consuming and has a negative impact on the environment. For every liter of desalinated water, about one and a half liters of highly concentrated brine is produced, which is discharged back into the seas and oceans, which disturbs the balance of the ecosystem.
Israel is an often cited example of dealing with water scarcity, which has caused severe economic losses in the past.
Currently, almost 90 percent. The country's wastewater is treated (four times more than any other country) and reused for irrigation of the fields. In addition, several private desalination plants sell water to the government, which supplies about a quarter of the demand for drinking water.
Experts emphasize that the expenditure on new technologies for purification and desalination was preceded by decades of educating the public on water saving, which only increases the efficiency of the entire system compared to other countries.
The UN report published on Monday repeatedly emphasizes that, unlike most natural resources, determining the "true" value of water is extremely difficult and therefore its importance is not adequately reflected in political discourse and financial investment in many parts of the world. This leads not only to inequalities in access to water resources and water services, but also to inefficient and unsustainable use and degradation of water resources.
"Water has infinite value because without it there is no life and cannot be replaced. The effort and expense made in finding water beyond the Earth and the recent joy of finding it on the Moon and Mars are examples of this. It is a pity that it is so often regarded as something obvious on Earth, "conclude the authors of the report.
Joanna Baczała (PAP)