Of late, news of water shortage and depletion has been on the rise all across the world. The water crisis has been gripping many countries in Africa, South America, Asia and North America. Climate change is one of the major factors for our water woes. The frequent period of drought, fluctuating precipitation patterns and skyrocketing demand for water have been driving this water crisis. Additionally, burgeoning population, poor irrigation and agricultural land management practices have declined the water table in many cities. Shrinking Lake Chad, drying lakes of California and Cape Town coming close to Day Zero are some of the instances in recent years which highlight how grim the water crisis has become in the modern world. While at an individual level, we would need more awareness of the water management systems to tackle our water problems, at a larger scale, oceans can offer a possible solution in the form of water desalination.
Oceans account for 97 per cent of total water present on the earth and the remaining three per cent is freshwater. 90 per cent of the freshwater is used for agricultural purposes and the rest is used for drinking and industrial purposes. Such a huge amount of water in the oceans and seas can support humans for many years if the salt is removed. The process of water desalination — which is the removal of salt from saltwater with the help of technology to create drinking water — has emerged as a blessing for many countries which do not have sufficient sources of freshwater.
In countries such as Saudi Arabia, the US, Australia and Israel, water desalination plants have been generating potable water at a large scale catering to the water needs of millions. Israel depends on desalination for forty per cent of its domestic water. With reverse osmosis being the core process of water filtration, water desalination makes tens of thousands of gallons of freshwater accessible to the most water-deprived households in the world, each day.
The technology is still at its nascent stage and as the water crisis hit new areas, new cities and regions, its adoption has been increasing day by day. Currently, just 1 per cent of the world relies on desalination; as per a United Nations report, by 2025, 14 per cent of the world is expected to depend on this process. The investments in water desalination technologies have been increasing over the years. However, for a lot of poorer nations hit hard by the water crisis, water desalination plants are just not affordable owing to their high energy requirement to run these plants. Barring the economic reasons, there are several environmental concerns too which have been affecting marine life negatively. As the salt water from the oceans goes straight to these desalination plants, the process harms and kills many fish and other marine animals, which can disturb the entire marine ecosystem. Further, the salt concentration in oceans will only grow in years to come, which means more energy would be needed to filter the extra salt from the water, making the process more expensive. However, the process could be made affordable if the plants use renewable sources of energy such as solar and wind energy to run them. Further, the introduction of better environmental protection laws which could safeguard marine and other affected ecosystems can make water desalination much more scalable.