Impact Of Population Growth On The Environment Environmental Sciences Essay

The world has been experiencing a rapid increase in human population for the past 10, 000 years. According to the most recent U.N. statistics, population has grown from several millions back in the B.C. to over 6.6 billion in the 21st century. Even though the growth rate is gradually slowing, the U.N. population Division still expect the worldwide population to very much hit 9.1 billion by 2050.

We have all known for long that the human population is no doubt the chief contributor to environmental woes. The humans are the one demanding fossil fuels to power their tech-savvy lifestyles, clearing forests for agricultural use, and polluting the environment with their industrial activities. More people means more demand for natural resources either mined or drilled from below the Earth’s surface to be burned for energy. Assuming that each person contributes to a certain amount of the total demand, one could very much imagine the kind of strain that this 2.5 billion of additional population is going to cause to the Earth.

With the population expected to rise by that phenomenal amount, environmentalist and the others are getting more concerned with whether the Earth is still able to withstand that loads of demand. We also being concerned aims to examine the causes and impacts of this issue in the report, so that solutions could be proposed to alleviate it.

1.3 Focus

In our opinion, we feel that if we can solve the problem of the rising human population growth, we can also solve the environmental problems that is likely to stem from it. The explaination for this reasoning is simple and rather fundamental. The problems merely justify the need to do something about it, whereas the causes is the one that set off the problems.

As mentioned earlier on, the crux to the solutions lies very much with the causes itself. Therefore, one could very well expect us to first introduce the problems in the report, before moving on to the more crucial part, its causes and solutions.

1.4 Methodology

Information used for this study was mainly obtained from secondary sources such as books, online databases, U.N. publications, and other useful websites. A listing of these useful sources of information can be found at the Appendix 1 as attached in the report.

Human population

The world population refers to the total number of living humans on Earth at a given time. For the past 10, 000 years, the world has been experiencing a rapid increase in human population. According to the most recent U.N. statistics, population has grown from several millions back in the B.C. to over 6.6 billion in the 21st century.

Even though the growth rate is gradually slowing, the U.N. Population Division still expect the worldwide population to very much hit 9.1 billion by 2050. With most of the increase in Asia and Africa, in particular, the poorer nations that have no access to proper family-planning programmes.

An alarming issue – Rising human population

We have all known for long that the human population is no doubt the chief contributor to environmental woes. However, what little know of is that the human population is only one of the several factors that affect the environment. The extent to which population increase can be considered a problem is still reliant on other factors.

One widely used formula that could help us understand what factors could actually interplayed to cause that significant impact, would be the IPAT model that John Holdren from Harvard University came up with. This model represents how the total impact on the enviroment results from the interaction among population, affluence and technoloy.

An Increased population intensifies impact on the environment as more individuals take up space, use resources, and generate waste. As the population gets older it gets more affluent too, thereby demanding higher living standards to satisfy their ‘wants’. To meet the human’s instatiable ‘wants’, better technology would have to be developed to better mine fossil fuels, clear old-growth forests, or fish.

Assuming that everybody has to be fed, clothed, housed and hopefully supported by gainful employment. An increased population would actually means the intensification of the impact that the human population has on the Ecosystem. Hence, the problem is not only that the population is burgeoning. It is also that the usage of the resources, and environmental damages are also increasing at a phenomenol speed.

Approach

All of us would have known by now that a rising global population has devasting impacts on the Earth. It not only erodes the living standards of the world population, results in poverty in already poor countries, affect a country’s economy, but most importantly has a negative impact on the Ecosystem. We will in this chapter, look in depth how the rising global human population develops into a problem, and the various environmental impacts it has on the Earth.

The Problem of Rising Global Human Population

Urbanisation is being defined as the physical growth of urban areas as a result of global change. Moreover, It can also be interpreted as the movement of people from rural to urban areas with population growth equating to urban migration. The United Nations’ project suggested that 60% of the world’s population would live in urban areas at the end of 2030.

An increased in the population residing there would lead to an increase in consumption of energy, food, water, domestic goods, and land.

To accommodate to this increase in demand, more resource extraction, manufacturing, and agricultural production will have to take place. Considering the limited existing resources of an urban city, an expansion of the city would be needed for the above mentioned activities to take place.

This expansion of urban areas across the landscape is something also being defined as urban sprawl. In order for urban sprawl to take place, surrounding areas adjoining the edge of the urban cities will have to be made ready. This is usually done through habitat alteration such as, deforestation for urban cities surrounded by forest/mangroves, or land reclaimation for cities corteminous with islands.

Environmental Impacts

From the above illustration, we can see that a rising population will not only highten the rate of human activites but will also give rise to newer problems such as urban sprawl. All of these problems will then contribute to certain environmental woes which would interplay and lead to further consequences.

The following are some environmental issues that are either the direct or indirect impact of a rising global population:

Depletion of natural resources

Global climate change

Loss of biodiversity

Depletion of natural resources

Depletion of natural resources refers to the over exploitation of the exhaustible group of natural resources. This group of resources comes in the form of renewable and non-renewable resources. Renewable natural resources are those that can replenish themselves in a resonable amount of time, however, it can also be depleted should the rate of usage exceed the rate of regeneration. Whereas, non-renewable resources are those that only exist in a fixed quality, and either takes up to millions of year to replace themselves or does not possess the ability to recyle themselves.

As the human population rises, human activities such as urban sprawl, resource extraction, manufacturing, and agricultural production are expected to increase too. As all of these activities each demand a certain type of natural resources and energy to support them, an increase in human activities would equate to an increase in demand for these natural resources.

Some of the resources that are affected as a result of them are namely, fossil fuels, land, water, and minerals.

Fossil Fuels

Alongside the increasing demand for petrol and diesel to power transportation, industries and farming, huge quantities of fossil fuel such as crude oil is also needed in the manufacturing of plastic-made products.

With oil production likely to increase by nearly 40% from 2006 to 2030; as a result of only the increasing world energy demand of 60%. The real demand for oil is believed to be much more higher. According to British Petroleum the current world oil reserves stand at 1238 billion barrels. And present yearly world oil production stands at 31 billion barrels. If the current rate of oil discoverage were to remain stagnant or low, oil, the primary source of fossil fuel used to produce energy might very well be depleted before 40 years (The figure as calculated with current consumption rate and the level of reserves).

The following is a graph (Figure 1.0) that highlighted the increasing gap between the production rate and discoverage rate of oil supplies.

Figure 1.0 (adapted……………..)

Land and Water

Land degradation refers to deterioration or loss of fertility or productive capacity of the soil. Urban sprawl can dramatically transform the properties of soil, causing it to lose its water permeability and ability to perform essential duties. These duties include the loss of ability to sustain soil biodiversity, crop cultivation, and the reduced effectiveness as a carbon sink.

The following graph (Figure 1.1) showed the amount and types of land loss in various European cities that were the result of urban sprawl.

Figure 1.1 (adapted……)

On top of all that, rainwater which falls on areas with deterioted land will also be heavily polluted by tire abrasion, dust and high concentrations of heavy metals, which when washed into rivers will degrade the hydrological system. To add insult to injury, the level of water table will also decline as deterioted land can no longer allow water to penetrate throught it. According to the Organisation for Economic Co-operation and Development,  If current trends continue, 90 percent of freshwater supplies will disappear by 2030.

Setting all that aside, one still has to take into consideration the soaring increase in use of water for crop cultivation and human consumption. With the supply of water on the shorter end and demand for it on the rise, the UN Millenium Project, 2008a estimated that 3 billion people might face water scarcity by 2025. A remarkable increase from the current figure of 700 millions people.

If nothing done about this, the Earth will very soon run out of arable land to support crop cultivation and no longer have enough safe drinking water to support the rising global human population.

Minerals

Minerals are the backbone of the human civilisation, they are needed in almost all sectors of industries. If we were to look into the manufacturing sector and bulding sector, some minerals used by them would be gold, silver, iron, cemet, and copper. Since there is a direct relationship between the human population and the industries, a booming population will also lead to an increase in the consumption of minerals.

A good example to substantiate the direct impact a growing population would have on minerals would be the example on Spain. For years, the efforts to support the growing population in Spain, have resulted in major expansion of construction activities, mainly along the coast and around major cities. As a result, the consumption of concrete has also increased by a wide margin of 120 % since 1996, reaching a level of 51.5 million tons in 2005.

Taking into account the non-renewable characteristic of minerals and the direct relationship it has with the human population. A surge in the human population might cause the limited stock of minerals to undergo depletion in the near future.

Loss of biodiveristy

Biodiversity may be defined as the variation of life forms within a given ecosystem, biome or the entire Earth. Biodiversity is earth’s primary life support system and is a pre-condition for human survival. As population grow, develop and modify their environment, their activities inevitably affect biodiversity.

To understand the impacts of human population growth on biodiversity, a study into it had been carried out in Canada. The findings reveal that human activities such as agricultural activities, urbanisation, and manufacturing are the primary causes of the decline of biodiversity in Canada.

Agricultural activities

Agricultural is the production of goods and food through farming. It is reported that Agriculture has had a significant effect on biodiversity because of its prevalence over the landscape.

Loss of native habitat in Canada due to farming has been significant. As a result of agricultural activities, Canada lost more than 85% of shortgrass prairie, 80% of mixed-grass prairie, 85% of aspen parkland and almost its entire native tallgrass prairie. Loss of habitat, coupled with farming practises of using only a few strains genetically-engineered crop, has resulted in the endangerment of a disproportionately large number of plants and animal species in Canada.

To prepare a piece of land for agricultural activities, the natural vegetation has to be first removed from it. Without the natural vegetation’s protection, the topsoil, a surface layer of soil that is rich in nutrients and beneficial microorganisms, can be easily eroded away by surface water, or winds. In Quebec, it is estimated that 3.4 million tonnes of soil per year are eroded by water. Soil erosion renders an area barren and unsuitable for plants that were initially growing there. To add on to that, soil that has been washed away and deposited in waterways, also destroys the fragile life forms in it.

If water can carry away soil, it can also cause the runoff of pesticides and fertilizers that are applied in abundance to commercial crops, and of course the wastes of cattle and livestock. In Quebec, between 1990 and 1991, an impressive amount of 190 000 tonnes of nitrogen and 120 000 tonnes of phosphorus were applied to agricultural lands in the form fertilizers, or were present as livestock wastes. As these excess nutrients enter the lakes and rivers, Eutrophication of aquatic environment can occur; altering and degrading the biodiversity of aquatic ecosystems.

With 64 out of 105 developing countries studied by the UN Food and Agriculture Ogranisation seeing their population growing at a speed faster than the food supplies, the increase in agricultural activities worldwide is imminent. Therefore, one should expect the loss of biodiversity as a result of pollutants coming from agricultural activities to swell around the globe.

Urbanisation

It is estimated that between 1871 and 1991, the Canadian population living in urban centers have increased from19% to 77%. To accommodate to this increase, the initial urban centres that stand on 0.7% of Canada’s total area, have been expanding over the last few decades.

In the twenty years spanning 1971 to 1991, the total area of the Montreal Urban Community increased from 2674 km2 in 1971 to 3509 km2, the Quebec City area increased from 907 km2 to 3150 km2, and the Sherbrooke and Trois-Rivieres became classified as urban centers. With the majority of large cities located within the St. Lawrence lowlands, a ecozone that is very biologically rich. An expanding city is bound to displace the many species that depend on that ecozone as habitat.

Manufacturing

In Cananda, manufacturing is the main economy in Quebec, it not only employs the most number of people, but also contribute the highest proportion of Quebec’s GDP. Due to the unique nature of this sector of industry, many harmful pollutants are constantly being emited from its operations.

Water-borne pollutants include metals, organic chemicals, and suspended sediments that are usually found in industrial discharges. These toxic discharges when flow into the water, can inversely affect the biota in an ecosystem by killing them, weakening them, or deterioting their ability to reproduce. As mentioned earlier on, the majority of large cities are concentrated within the St. Lawrence watershed. Therefore, any harmful discharges from the industries can quickly reach and harm the living organisms in it.

Air-borne pollutants include carbon dioxide, sulfur dioxide, and acid precipiation that can usually be found in the smoke fumes from factories and motor vehicles. It had been found out that air emissions from the Inco steel smelter in Sudbury, Ontario were directly responsible for a significant portion of the acid rain in eastern North America. Consequently, the surrounding lakes, which is home to fish, mollusk and other amphibian populations, were acidified. Since these amphibian species will not be able to survive in acidic condition, a lake hit by acid rain will result in the death of them.

Furthermore, air-borne pollutants such as carbon dioxide and methane also give rise to a whole new environmental problem, which is being known as Global Climate Change. We will in the following paragraphs look into what this is all about.

Global Climate Changes

Global climate change refers to the change in global temperatures and precipitation over time due to natural variability or to human activity. Climate change may be limited to a specific region, or may occur across the whole Earth.

According to the Intergovernmental Panel on Climate Change (IPPC), ever since the start of the industrial revolution, atmospheric carbon dioxide levels have rose from 280 parts per million to 379 parts per million in the last 150 years. Furthermore, findings also concluded that there is a higher than 90 percent probability that human-produced greenhouse gases such as carbon dioxide, methane and nitrous oxide have caused much of the observed increase in Earth’s temperatures over the past 50 years.

While we all know that human activities were the cause of global climate changes, the main causes of the current global warming trend is actually the result of human expansion of “greenhouse effect” – a process in which the heat leaving the Earth is being trapped by the “greenhouse gases”.

Greenhouse gases include, water vapour, carbon dioxide, methane, nitirious oxide, and chlorofluorocarbons. On Earth, the composition of natural greenhouse has been constantly altered by human activities. Over the years, the burning of fossil fuels like coal and oil has increased the concentration of atmospheric carbon dioxide. On a smaller scale, the clearing of forests for agriculture, industry, and other human activities, have also resulted in an increase in the concentrations of greenhouse gases.

From the relationship between the human population and human’s industrial activities, it is undisputed that any increase in the human population will lead to an increase of greenhouse emissions, which will eventually accelerates the rate of global climate change.

The following table summarises the regional impacts of global climate change by the IPPC:

Region

Impacts

North America

Decreasing snowpack in the western mountains; 5-20 percent increase in yields of rain-fed agriculture in some regions; increased frequency, intensity and duration of heat waves in cities that currently experience them.

Latin America

Gradual replacement of tropical forest by savannah in eastern Amazonia; risk of significant biodiversity loss through species extinction in many tropical areas; significant changes in water availability for human consumption, agriculture and energy generation.

Europe

Increased risk of inland flash floods; more frequent coastal flooding and increased erosion from storms and sea level rise; glacial retreat in mountainous areas; reduced snow cover and winter tourism; extensive species losses; reductions of crop productivity in southern Europe.

Africa

By 2020, between 75 and 250 million people are projected to be exposed to increased water stress; yields from rain-fed agriculture could be reduced by up to 50 percent in some regions by 2020; agricultural production, including access to food, may be severely compromised.

Asia

Freshwater availability projected to decrease in Central, South, East and Southeast Asia by the 2050s; coastal areas will be at risk due to increased flooding; death rate from disease associated with floods and droughts expected to rise in some regions.

Figure 1.2 (Adapted from: http://climate.nasa.gov/effects/)

On top of all that, the global climate change also indirectly resulted in the loss of biodiversity. As the global temperature rises, crop that used to grow best at certain temperature, will not be able to adapt, and will die off eventually. On the other hand, the higher temperature will also melt the glaciers and the artic sea ice, a habitat to animals such as, polar bears and penguins.

Conclusion

According to U.N. population division, the worldwide population has a high likelihood of hitting 9.1 billion by 2050. From this figure, it is easy to see that even if the current world population of 6.6 billion does not increase it consumtion per capita, we will still have to use up more resources to support this higher number of population. Hence, there is an urgent need to do something about the rising global huamn population, as the devasting envrionmental effects we discussed earlier on have a direct relationship with it.