Global Environmental Change


Water is among the most valuable natural resource found on the earth. The human body can survive for a number of days without food, but its systems will fail without water. The ecosystem requires water in order to supply human beings with food, energy and other resources essential for survival (Miller and Spoolman 312).

Similarly, water is critical for transforming the earth’s surface. Furthermore, water is a key component used in moderating and controlling the weather patterns (Maxwell 3). In this case, it purifies the environment by removing and adulterating impurities and wastes. On an economic perspective, water is a critical resource because it determines the poverty rate. Water supply problems affect health and food production (Saddleback 15).

This paper examines how population growth affects the water system and concerns related to drinking fresh water. The paper further looks into the shortage of clean water, and how the second law of thermodynamics can be used in explaining energy conservation in a source- separation designing program.

What role does population growth play in water supply problems?

Population growth is a key element determining water supply problems. As the population increase, demand for water also increase. This is because water is required for; household, agriculture and industrial use. Miller and Spoolman (313) illustrate that excessive use of water leads to low water tables, dwindling lakes and dying wetlands. In addition, the amount of waste-water discharged increases pollution. This ultimately threatens the ecosystem because the hazardous waste finds their way back to water.

Urbanization is a consequence of population growth. The growth of large cities subsequently affects the climate and hydrological system. Urbanization requires using resource like; timber, wood, paper and water in building houses, offices and schools. Besides building, more than two billion people use firewood and charcoal for cooking and heating (Millennium Ecosystem Assessment 26).

The demand for timber has contributed to deforestation, reducing the vegetative cover. Since the ecosystem of the natural forests determines the hydrological cycle, deforestation has led to water supply problems. It has created a ‘heat island’ due to reduced evapotranspiration.

Gupta asserts the human settlement pattern due to population growth is not in tandem with the hydrological cycle (399). It is based on water catchment areas. Also, Gupta cites urbanization has a phenomenon creating an impervious cover on underground water and watersheds (399). The Impervious cover leads to impervious upsurge which modifies the drainage system and changes the microclimate. Furthermore, urban settlement affects water supply through water distribution and sewer systems.

Identify three ways in which humans are negatively impacting the water cycle

Human beings have negatively affected the water cycle through various activities. Gupta indicates pollution as a serious consequence brought about by human activities (248). Human beings pollute water at a point or non point sources. According to Gupta (346), it is easy to monitor point source pollution.

However, non point pollution originates from diverse sources making it difficult to track. In less developed countries, pollution is on the rise because they do not have resources to build effective waste management systems. Moreover, developed countries lack policies that regulate pollution (Gupta 535).

The water cycle is polluted by industrial, agricultural and household wastes released to water. Agricultural pollutants include; pesticides, herbicides, insecticides, and fertilizers. When these chemicals are washed down by rain or irrigation water, they end up in lakes, rivers or other water sources. The first impact is that pollutants can disrupt the life system of organisms living in water (Maxwell 3). Secondly, the chemicals used have a high percentage of phosphorus which alters the nutrient content of water.

When the water system is loaded with nutrients eutrophication occurs (Gupta 399). In hot weather, the excess nutrients promote the growth of bloom, duck weed or water hyacinth. Hence, their increase hinders the growth of useful water life such as fish. Industrial pollutants also contain harmful substances, for example, coal ash, which is produced in power plants. When coal ash is dumped in water, it causes contamination.

Most containers are made of plastics. The polymers used to produce plastics take years to decompose. When disposed carelessly, plastics pollute waterways and systems. Apart from pollution, humans affect the water cycle through wastage. If people would use water efficiently, there would be no need for excessive withdrawal of water. The other activity that negatively impacts the hydrological cycle is mining. Mining contaminates and destroy underground resources.

Summarize the public health concerns related to fresh drinking water worldwide

The lack of fresh drinking water appears to be a critical environmental challenge worldwide. Franks, in his book Water: A Matrix of Life claims that diarrhea, schistosomiasis, and cholera claim about three million lives every year (197). Statistics from the World Health Organization show there are about 3-5 million cases of cholera reported annually (World Health Organization). Miller and Spoolman also claim that 3900 children under the age of five years die daily from waterborne diseases (World Health Organization).

United Nations reported that waterborne disease lead to more deaths compared to war and violent acts (Miller and Spoolman 532). Other statistics from the World Health Organization reveals that more than one billion people have no accessibility to clean water and sanitation.

In countries facing drought or famine, people have no option, but to drink the available water. To access drinking water, they probably have to walk for a long distance. In less development countries, fuel is a scarce resource. Most people cannot afford to waste this precious commodity to boil drinking water.

Why is there a shortage of clean water for the world’s population to consume?

According to Miller and Spoolman, fresh water is being used unsustainably. The population is either wasting it or polluting it (123). Additionally, water management authorities are charging the citizens too little for the valuable resource. With the increase in population, more water is required for economic activities such as irrigation and industrial use.

These activities in turn contribute to waste production, hence, contaminating water resources. Furthermore, the lack of clean water is caused by an imbalance of water use and resources (World Water Council). The imbalance created contributes to water stress. Consequently, the quality and quantity of water deteriorates because of overexploitation and eutrophication respectively. The Millennium Ecosystem Assessment Forest and mountain ecosystem supply the largest quantity of fresh water (World Water Council).

The increase in human population endangers these ecosystems due to urbanization an economic development. The effluents and emissions from industries cause acidic depositions in the air. Acidity alters the pH levels of water which consequently impairs water resources (Maxwell 3).

Water wastage also contributes to the shortage of clean water. Water is wasted by luxuries such as showers and sprinklers. Miller and Spoolman assert that the low cost of water promotes wastage (328). The low cost water leaves consumers with no incentive to conserve water or invest in technology that saves water.

The appropriateness of the second law of thermodynamics, and why a well-designed source-separation recycling program use less energy and produces less pollution than a centralized program that collects mixed waste over a large area and hauls it to a centralized facility where workers or machinery separates the waste for recycling.

The second law of thermodynamics describes the loss of heat during energy transformation. Buckingham and Turner 69 allege that ‘When energy changes from one state to another, heat is lost’. The transformation of energy moves from order to disorder, a state known as entropy.

Therefore, thermodynamics nullifies perfect recycling due to degradation of quality. Through recycling, waste products lose energy or heat. A properly designed source- separation recycling system, use less energy. This is because human populations are engaged in the process of separation (Last). The garbage is sorted in different categories before the waste is collected. Compared to source separation systems, centralized systems use machinery which requires fossil fuel (Buckingham and Turner 69).

The fossil fuel used in these systems emits hazardous chemicals. Thus, the chemicals emitted pollute the air affecting the ecosystem. However, despite this effect, centralized systems play a critical role in reducing environmental waste at the cost of pollution. This means centralized system move from a source of order to disorder (Buckingham and Turner 69). In addition, it is expensive to buy the equipments required to sort waste in a centralized system.

The other challenge of a centralized waste separation facility is the use of machinery to separate the different components. A machine may not be successful because it lacks the ability to separate component like plastics such as hard and soft plastic. Moreover, some of the waste components may be contaminated and, therefore, may not meet recycling specifications. When the users of these materials discover that the specifications have not been met, they have to return the products. This action is uneconomical as it wastes time and resources in the process.

Works Cited

Buckingham, Susan and Mike Turner. Understanding Environmental Issues. Los Angeles: SAGE Publications, 2008. Print.

Franks, Felix. Water: A Matrix of Life. Cambridge: Royal Society of Chemistry, 2000. Print.

Gupta, Sushil K. Modern Hydrology and Sustainable Water Development. Chichester, West Sussex, UK: Wiley-Blackwell, 2011. Print.

Last, Steven. , 2007.

Maxwell, Steve. Business of Water: A Concise Overview of Challenges and Opportunities in the Water Market : a Compilation of Recent Articles from Journal Awwa. Denver, CO: American Water Works Association, 2008. Print.

Miller, G T, and Scott Spoolman. Living in the Environment. Pacific Grove, CA: Brooks/Cole, 2012. Print.

Millennium Ecosystem Assessment. Ecosystem and Human Well- being: Our Human Planet: Summary for Decision-Makers. Washington, DC : Island Press, 2005. Print.

Saddleback.Water Conservation. Irvine, CA: Saddleback Educational Publishing, 2009. Print.

. Water crisis. 2010.

World Health Organization. . 2011.

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