Read the following passage carefully and answer the questions that follow.
Water covers more than two-thirds of the planet, largely in the form of oceans, seas, lakes and ice. The majority of this water is salty and cannot be used for human consumption or for irrigating plants.
Less than one per cent of the earth’s water is unsalty and available for human consumption. In theory, this amount could support four times the present human population, but in reality water supplies are spread unevenly around the world. About two billion people in 80 countries live in areas of chronic water shortage – a situation that will worsen as human and animal populations grow. Particularly affected are most of Africa, the Middle East, north Asia, and Australia. Many countries are draining water from aquifers (an underground level of the earth or porous rock which contains water) faster than those aquifers can replenish themselves.
Due to population growth alone, water demand is expected to double in more than half of the world’s countries. Most of this increasing demand is for irrigation and industrial uses. About 69 per cent of the world’s fresh water goes for irrigation, about 23 per cent for industry and 8 per cent for household use. In many arid and semi-arid areas, population growth has raised food demand to a level that can be met only through irrigation. Some countries lie within climatic zones most prone to drought and other water problems. Unfortunately, some of these countries have high rates of population growth. For example, the populations of Kenya, Ethiopia and Iran may well double within 25 years, yet the amount of water available to these countries will remain the same.
Even with efficient irrigation and other water-use methods, many countries in the Middle East and Africa may not be able to meet their water needs by 2025 if population growth continues at present levels. By that date, some believe that as many as 25 developing countries may have reached the water barrier, which is the minimum amount of water needed by each person, assuming access to advanced technology to maximize water conservation. Another 24 countries may experience seasonal shortages and problems with water quality.