Water shortage has been a worrisome problem facing the world. We mostly live in water-rich countries washing dishes, watering plants and taking a shower, it’s hard to imagine or realize there will be inadequate water supply for the world one day. Water is a finite resource such that the amount of fresh water supply provided by the hydrological cycle will not increase. Water occupies 71% of the world’s surface and is an integral part of the global hydrologic cycle which includes like precipitation, evaporation and soil moisture. Without this hydrologic cycle, even a human being cannot live for more than 3 days. It is easy to predict how the world will look like without water. So, water shortage, a life-or-death issue, demands immediate attention from every members of the planet.
a. Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans. People generally think global warming lead to ice melting and there will be more sufficient water supply. However, according to a study carried by the journal Nature, if the Earth warms just a degree or two Celsius in coming decades, regions that depend on runoff from mountain snows for drinking water and farming will face shortages. Actually water shortage caused by global warming is due to the increase in demand for water but not a drop in water supply. When there is global warming, the rise in earth’s temperature will lead to an increase in the evaporation rate of the moisture in soils, thus increasing the demands on irrigation in agricultural activities. Moreover, higher temperature will speed up the water cycle as water evaporates at a faster rate and rain more often and plants will benefit less. There will be the depletion of water tables and lead to water shortage. Therefore, although the amount of water available in the world does not change when there is global warming, the rise in demand for water can still trigger the problem of water shortage.
b. Increasing population
The world population increase by 1%-3% annually and more people results in a need for more water. Industrial, agricultural and economic activities increase its water demand too. In some regions of even the most developed countries, people consume about 80% of their available fresh water supply at any given point in time. Problem exists when the increasing demand of water cannot keep pace with the limited supply of water. There is a report called “More people, Less Water” commissioned by Population Matters from an LSE graduate student which reviewed that people will need between 1.5 and 4.9 million more tonnes of water (cubic metres) per day if the population keep on rising. These are worrying figures implying the danger of water shortage and a rise in the cost of building new pipelines, sewage treatment and more long-distance pumping etc. This problem will keep on worsening if we do not take any actions to conserve water properly and gradually lead to water shortage which affects everyone’s life.
Polluting water will reduce the water supply and lead to the problem of water shortage. Pesticides and fertilizers used in agriculture, sewer overflows and oil and grease from roads are examples of pollutants which will eventually run off into the water systems. Other sources of excess nutrients include lawn fertilizers, pet and farm animal waste, decaying plant material, failing septic tanks, and inefficient sewage treatment plants. Besides, industry such as industrial plants and municipal wastewater treatment plants is also the leading producer of sewage which will enter streams and rivers and ultimately lakes, estuaries and coastal waters. According to the statistical study carried by the Shanghai Star magazine, producing one ton of steel requires 20 to 60 cubic metres of...