A vast amount of water is found on the earth, which is why it is also called ‘Water Planet’.
However, due to its uneven distribution, all the living organisms on earth are not able to get water resources in equal proportion.
Out of a total quantity of 1.5 billion cubic km in nature, only 12,500 to 14,000 billion liter water is available annually for use by human beings.
Thus, whereas about one-third population of the world at present is not able to get fresh water, a population of 2.8 billion of 48 countries up to 2025, and a population of 4 billion of 54 countries up to 2050, may face water crisis. These figures are 40 per cent of the projected population of the world.
The present water crisis scenario has clarified that 1.1 billion population of the world does not get sufficient fresh water, or one out of every six persons faces water crisis. Apart from supply of fresh water, from the qualitative point of view also it is clear that 2.5 billion population of the world does not get sanitary facilities and 20,000 children die every year of water-borne diseases.
In India, 170 million people do not get fresh water in sufficient quantity. Water crisis started in the beginning due to unevenness of distribution and increasing demand of the population, but in present times the qualitative aspect has also been added to the quantitative aspect.
If the total quantity of water available in India is made pollution-free, it is sufficient for the existing population, but along with rivers and lakes, even groundwater is becoming polluted. In the beginning, pollution was considered as limited up to ground and oceans only but now atmospheric water (vapour) is also taking the form of acid rain. Thus, all living organisms are suffering from the problem of water crisis.
The seemingly vast amount of water on earth is thus, finding itself unable to quench the thirst of the inhabitants. The layer of white sheet (snow) spread on the earth, which is a huge reservoir of fresh water, is slowly melting away. Along with it, changes in quantity and nature of rain are taking place. All these changes have been made by the human community demanding water.
On one side, there was uneven distribution of water in nature since the very beginning, and on the other side, man has made this invaluable gift of nature beyond the reach of living organisms by his selfish behaviour. Hence, due to water crisis, some day, man too would also face extinction like some animals.