The Global Challenges of Desalination - Thesis Example

Download file to see previous pages A global outlook of the global freshwater situation by Few Resources (2016) reveals that only 2.5 percent of the entire water on the Earth's surface is could be considered to be freshwater. Few Resources (2016) further reveals that a majority of the amount of water is saline water, which is in the oceans. Some 30.1 percent of the 2.5 percent of the freshwater is groundwater found in aquifers. An additional 68.6% of the freshwater is from polar caps and glaciers, while a mere 1.3 percent originates from rivers and lakes (See Figure 1) (Few Resources 2016). This implies that humans face significant freshwater scarcity, as they mostly rely on groundwater and surface water from rivers and lakes.

In another study by Unesco (2015) of the distribution of water resources globally, it was concluded that runoff water and water from precipitation is unpredictable, as different regions of the earth receive diverse quantities of freshwater annually. Unesco further revealed that the increasing climate change was actually exacerbating the risks linked to the disparities in freshwater resource distribution and accessibility.

The increased water temperatures because of warmer climates that result from climate change and increased release of waste heat is also projected to reduce accessibility to freshwater by increased forms of water pollution, including the release of salts and pesticides, nutrients, dissolved sediments, and thermal pollution. Greater focus has, therefore, been on groundwater as it has a significant function in diversifying freshwater supply. According to UNESCO (2015), of the overall global population, some 2.5 billion people are wholly dependent on groundwater resources for use.

Despite this, there is a concern that the currently available groundwater resources are becoming increasingly depleted because of the increased human population and their reduced rate of replenishment rates (El-Shamy & Said 2014). The depletion rate of the groundwater is estimated to be at least 20 percent due to over-exploitation. This has led to severe implications, including intrusion into saltwater and subsidence of land. There is a significant decline in the levels of groundwater globally. For instance, the withdrawal of fresh water in the Arabian Peninsula, for instance, is was approximated to be 505%, as a fraction of renewable water resources internally. Unesco (2015) also estimated that the overall quantity of groundwater footprint is nearly 3.5 times the size of aquifers, while some 1.7 billion people currently reside in regions where they are at risk of freshwater scarcity because of depleted groundwater resources. On the other hand, some 80% of aquifers contain groundwater footprint estimated to be less than their regions. This implies that the net global value is dependent on the few available yet immensely overused aquifers.

An additional major challenge to freshwater is increased human interference. As found by Unesco (2015), the manner in which humans have interfered with nitrogen and phosphorus cycles has surpassed safe levels. For this reason, an increase in surface water eutrophication is projected to increase globally, at least until 2030 before it could reach stable levels in the developed nations, despite worsening in developing nations. This portends a further threat to freshwater accessibility in developing nations.

According to Unesco (2015), the number of lakes containing detrimental algal blooms may rise by nearly 20 percent, until 2050. At the same time, discharge of phosphorus would rise in a more rapid manner compared to silicon and nitrogen, aggravated by the rapidly growing amounts of dams globally. ...Download file to see next pages Read More