UNIT 9: Environmental Management and Population Dynamics
Key unit competence: To be able to overcome environmentaldegradation.
Introduction
Environmental management is an issue many governments in the world
are grappling with. Environment refers to the surrounding or conditions
in which a person, animal or plant lives. There are six key elements of
natural environment that are significant when talking about environmentaldegradation. These are:
1) Atmosphere
2) Water resources
3) Soil
4) Oceans
5) Forests6) Living species
Many international fora have been held to discuss ways of conserving the
environment. Population increase has been blamed for many environmental
problems. In this unit, we will study in depth environmental managementand population dynamics.
9.1 Rwandan and global environmental degradation
Activity 1
1. What do you think are the causes of environmental degradation?
Environmental degradation is the deterioration of the environment through
depletion of resources such as air, water and soil. There are many causes ofenvironmental degradation. The following are some of the causes:
1. High population growth
2. Deforestation
3. Wetlands encroachment
4. Overstocking
5. Monoculture
6. Pollution
7. Landfills8. Natural causes
1. High population growth: Rapid population growth puts strain on
natural resources which results in degradation of our environment. More
population means more demand for basic needs. Most of these basic needs
such as food, clothes and shelter are obtained from the natural resources.
As the population increases, more space to grow food and build homes is
needed. This leads to other factors of environmental degradation: wetlandencroachment and deforestation.
2. Deforestation: Deforestation involvesthe cutting down of trees. Trees can be
felled for various reasons. The most
common reasons are:
i. To use of forest land for agriculture or
animal grazing
ii. To harvest wood for fuel and house
construction
iii. Logging to make way for more homes and industries
3. Wetlands encroachment: Wetlands are places where there is shallow
water or very soggy soil at least part of the time. They include marshes
and swamps. Wetland encroachment involves intrusion of humans into such
natural areas either for farming or settlement. Wetlands play a vital role in
conservation of the environment. They cleanse and rejuvenate rivers. They
also prevent flooding by holding water. In this way, wetlands help keep river
levels normal and filter and purify the surface water. During storms, and
whenever water levels are high wetlands accept water. When water levels are
low, they slowly release water.
4. Overstocking: Overstocking of grazing animals has impact on the
environment in two major ways. First, there is the physical impact of the
animal on soil as they move around. Secondly, there is the chemical and
biological impact of the faeces and urine that the animals deposit to soil.
Physically damaged soil can be even more susceptible to the chemical and
biological impact of faeces and urine.
5. Monoculture: Monoculture, also known as monocropping, is where
farmers opt to specialise in farming only one type of crop year after year.
This practice has severe implications on the environment as it depletes
nutrients from the earth and weakens the soil making it unable to support
healthy farming. Once the soil weakens, farmers are forced to use chemical
fertilizers to encourage plant growth and fruit production. These chemicals
in turn disrupt the natural make-up of the soil and contribute further to
nutrient depletion. Monocropping also contributes to the spread of pests and
diseases. These are further treated with chemicals. When these chemicals
reach ground water or become airborne, pollution results.
6. Pollution: This is the contamination of air, soil, or water by the discharge
of harmful substances. Pollution can be on air, water or land.
7. Landfills: A landfill is a place where refuse and other waste material are
buried and covered with soil. They come from the large amount of waste that
gets generated by households, industries, factories and hospitals.
8. Natural causes: Things like avalanches, quakes, tidal waves, storms, and
wildfires can totally crush nearby animal and plant groups to the point wherethey can no longer survive in those areas.
Exercise 1
Discuss with a friend the constituents of the environment and showhuman dependence on the environment.
Effects of environmental degradation
Activity 2
What effects of environmental degradation do you see around yourschool?
1. Impact on human health: Air pollution from toxic gases coming from
industrial exhaustion can cause respiratory problems like pneumonia and
asthma. Millions of people are known to have died due to indirect effects
of air pollution. Noise pollution can cause irreparable damage to our ears
when exposed to continuous high sounds like honking of vehicles on a
busy road or machines producing a lot of noise in a factory or a mill.
2. Global warming: This is the gradual increase in the overall temperature
of the earth’s atmosphere. It is generally attributed to the greenhouse
effect caused by increased levels of carbon dioxide and other pollutants.
3. Loss of biodiversity: Biodiversity is the variety of life in the world or
in a particular habitat or ecosystem. Pollution leads to loss of various
kinds of life right from small organisms, to aquatic life to human life.
Biodiversity is important for maintaining balance of the ecosystem. This
happens through combating pollution, restoring nutrients, protecting
water sources and stabilising climate. When any kind of life in the
ecosystem is lost, one of these elements is affected. Deforestation, global
warming, overpopulation and pollution are few of the major causes ofloss of biodiversity.
4. Ozone layer depletion: Some air pollutants lead to depletion of the
ozone layer which is responsible for protecting the earth from harmful
ultraviolet rays. Its depletion leads to emission of harmful radiations back
to the earth.
5. Effects on tourism industry: When there is water pollution and the
green cover is replaced by plastic waste and other landfills, the natural
environment that constitutes tourist attraction sites such as waterfalls,
wetlands and wildlife are destroyed. This will definitely affect the tourism
industry. Landfills are also known to produce foul smell when burned and
they pollute the environment and destroy the beauty of the city. This can
be a setback to tourism.
6. Droughts: Depletion of natural resources such as forests due to
deforestation interferes with climatic conditions such as rainfall as the
water catchment areas are interfered with in the process. Intrusion inwetlands is another cause of lack of rainfall.
7. Desertification: Cutting down of trees can lead to desertification.
9.2 Conservation of the environment
Activity 3
In what ways do you think we can conserve the environment in Rwanda?
Rwanda has done a lot towards the conservation of nature. It’s a national
policy for all citizens to plant trees. The ‘cut one, plant two’ policy has almost
become a common practice though it’s still challenged by the unsensitised
members of the society. This is aimed at averting environmental degradation,
adverse climatic changes and the sustainability of the natural environment.
Environmental conservation is a gradual process of small changes that are
more sustainable and can improve life. The following are ways of conserving
and protecting our environment:
1. Planting trees
2. Conserving water
3. Ensuring proper disposal of waste
4. Using less fossil fuel-based products
5. Buying recycled products
6. Protecting wildlife
7. Educating others on environment friendly habits
Exercise 2
With a reference to your own home as a Rwandan, explain some of
the activities you have tried to do in order to be identified as a natureconservationist.
9.3 The relationship between economic growth, social development
and environmental protection
Activity 4
In groups, choose representatives and help them prepare a 5-minutes talk on
the impact of war on the environment.
The three concepts are closely linked in that economic growth ensures the
satisfaction of material human needs and aspirations. This leads to social
development.
All human activities that are designed and implemented for the economic
growth of a country and the social needs may impact on the environment
either directly or indirectly.
However, in as much as human beings strive to achieve social development,
environmental conservation should be observed. Economic development
is associated with technological and industrial advancement. If people are
not sensitive to the environment, so much can go wrong in matters of the
environment while pursuing economic growth.
Some economic activities can be destructive to the environment even though
they are income generating. For example, in commercial agriculture, farmers
may have to use fertilisers and pesticides in order to have higher produce
that maximises profits. The practice can lead to economic growth but at the
same time the chemicals are likely to destroy the natural resources such as
the soil and water.
Other human activities that can have adverse effects on the environment
include: diversion of water courses, the extraction of minerals, emission of
heat and gases into the atmosphere due to industrial processes, deforestation
as a result of people using trees as raw materials to make commercial
products and genetic manipulation of natural plants to have more produce
at lower costs.
It is also important to note that environmental degradation can be quite
costly to a country. The cost of land reclamation is high. These may involve
restoration of green cover, cleaning up of landfills and protection of
endangered species.
The economic impact can also be in terms of loss of tourism industry. When
the natural resources that serve as tourists’ attraction sites are polluted and
diminished, this impacts negatively on the tourism sector. When there are
fewer tourists visiting a country, the revenue also goes down and as a result
the socio- economic development of that country is affected.
Another way in which environmental protection is related to socio- economic
development is that pollution can cause diseases on the population. Disease
is an economic aspect in the society because it means incurring costs in
medical procedures and incapacitating a part of the population since when
people get sick, they are less productive.
Therefore, even as we strive for economic growth and social development,
we should avoid over-exploitation of natural resources to avoid depletion. We
should pursue development that encourages environmental sustainability.
Exercise 3
Discuss how man’s desire to achieve economic growth and social
development has impacted on the environment.
9.4 The benefits of renewable energy resources in comparison
with unsustainable finite resources
Activity 5
Give the types and examples of energy resources that are used in Rwanda
An energy resource is something that can provide energy. Energy can be
in the form of heat, light, a force that moves objects, electricity etc. Energy
consumption among human beings has increased over time.
Most of the energy we use today comes from fossil fuels. These have
consequences on the environment. This is because, they are non- renewable
and when burnt, they produce emissions that pollute the environment. Fossil
energy sources include oil, coal and natural gas. Fossil fuel industries drill or
mine these energy sources, burn them to produce electricity, or refine them
for use as fuel, for heating or transportation. A high percentage of human
emissions come from burning fossil fuel.
Energy sources can be classified into two types: non-renewable andrenewable.
1. Non-renewable energy resources are the resources that can be exhausted
by use. Examples of these are the fossil fuels which include coal, gas, oil
etc. They are also referred to as unsustainable finite resources.
2. Renewable energy resources are those that regenerate as fast as they are
consumed and are continually available. Examples are: wind, water, solar
and geothermal.
There are many forms of renewable energy. Most of these renewable
energies depend in one way or another on sunlight. Solar energy is the directconversion of sunlight using panels or collectors.
9.4.1 The advantages and disadvantages of renewable energy
resources
Advantages
1. They are renewable and therefore sustainable. They will never run out.
2. Renewable energy facilities generally require less maintenance than
traditional generations. Their fuel is generated from natural and available
resources which reduces the costs of operation.
3. Renewable resources produce little or no waste products, hence they
have minimal impact on the environment.
4. Renewable energy projects can extend economic benefits to many
geographical areas since most projects are located away form large urban
centers and suburbs of capital cities. These economic benefits may befrom the increased use of local services as well as tourism.
Disadvantages
1. It’s difficult to generate the quantities of electricity that are as large as
those produced by non-renewable fuel generations. This implies that
we may need to reduce the amount of energy facilities or if not, have a
balance of many different power sources.
2. There is unreliability of supply because renewable energy relies on the
weather for its source of power. Hydro generations need rain to fill dams
to supply flowing water. This causes unpredictability and inconsistence.
3. The current cost of renewable energy technology is by far higher than
the fossil fuel generation. This is because it is a new technology and assuch it has a large capital investment.
9.4.2 Advantages and disadvantages of non-renewable energy
resources
Advantages
1. They seem abundant e.g. oil, gas and coal. It is believed that if channelled
correctly, the supplies will be safe for the future generations.
2. They seem widely available and affordable e.g. oil and diesel are still good
choices for powering vehicles. They are cost effective and much easy to
produce and use. They have market value e.g. the produce makes money
and pays workers. This boosts the economy.
3. The non-renewable energy sources base can help the governments
to possess bargaining tool to help their economy stay afloat despite
struggling with their trade practices
.
Disadvantages
1. Because they come from sources on earth, once they are used up, they
can’t be replaced or revitalised.
2. Pollution through the products they leave behind and mining causes
damages to the environment. Fossil fuels contribute to global warming
through the high levels of emissions that they produce.
In conclusion, renewable energy resources, unlike the non-renewable
resources, are sustainable. They can never run out and hence the futuregeneration can also use them.
Exercise 4
a) Identify some of the key resources that man harvests from nature for
survival but must be consumed sustainably.
b) Explain the merits and demerits of the different types of energyresources used in Rwanda.
9.5 Extended Work
a) In your groups, you have about 3 weeks to research information about an
energy saving stove, write detailed notes on how it is constructed.
b) You are then advised to use local raw materials to construct an energysaving stove which you will share with your parents.
9.6 Unit summary
Causes of global degradation
1. High population growth
2. Deforestation
3. Wetlands encroachment
4. Overstocking
5. Monoculture
6. Pollution
7. Landfills8. Natural causes
Effects of environmental degradation
1. Ill health
2. Global warming
3. Loss of biodiversity
4. Ozone layer depletion
5. Desertification
6. Decreased earnings from tourism
7. Drought
How to conserve the environment
1. Planting trees
2. Conserving water
3. Ensuring proper disposal of waste
4. Using less fossil fuel-based products
5. Buying recycled products
6. Protecting wildlife7. Educating others on environment friendly habits
9.7 Test your competence
Read the case study below and then answer the question that follows.
Charles lived on the slopes of a mountain. He kept so many cattle in his
small piece of land. Because they destroyed all the vegetation in his land, soil
erosion became a problem to him. Gulleys cut across his farm. His animals
could not cross from one side of the farm to the other. Soon, they had littleto eat. To reclaim the land, Charles started building gabions.
Question
Write an essay showing the environmental degradation that Charles faced
and the approaches he used to conserve his farm. Suggest other possibleconservation methods that Charles could use.