5.0: ENVIRONMENTAL ISSUES AND MANAGEMENT

 

5.0: ENVIRONMENTAL ISSUES AND MANAGEMENT

5.1: The concept of environment

Concept from this subtopic

a.    Meaning of environment

 Environment refers to all external conditions surrounding an organism and which have influence over its behaviour and activities.

Or

 are all things that sounding us (human beings)

5.2: Importance of environment

Concept from this subtopic

a.         To explain the importance of environment

Importance of environment

I.To support the life of living organisms

II. Enhance tourism due to presence of attractive features such as Mount Kilimanjaro.

III.It is a source of natural resources: for example, animals, vegetation and minerals

IV.Environment sustains food chain. 

V.provides cultural services: for example, nyumbanity forest in Njombe

VI. It provides socio-economic services to the societies. For example, medicine, water and fuel.

5.3: Environment problems

Concept from this subtopic

a.         Identify environmental problems

b.         Analyses causes, extent and effect of the loss of biodiversity

c.         Analyses causes, extent and effect of pollution and waste management

d.         Explain the causes, extent and effect of fast rate of population and urban growth on environment

e.         Examine causes, extent, effect and impact of desertification

f.          Impact of poverty on the environment

g.         Analyses the causes and consequences of global climatic change on environment

ENVIRONMENTAL PROBLEMS

Environment problems these are hazard, disasters or calamities that result into destruction of environment

Or

are the harmful aspects of human activity on the biophysical environment.

The following are environmental problems

i.Environmental pollution

ii.Loss of biodiversity.  

iii.Soil erosion and land degradation

iv.Desertification.

v.Flooding.

vi.Acid rain.

vii.Harmful radiation.

viii.Drought

causes, extent and effect of the loss of biodiversity

 Biodiversity refers to the variety of species of organisms on the Earth's surface or its variety and variability of life on Earth.

Causes loss of biodiversity

i.Natural causes

i.Floods

ii.Drought

iii.Lighting

iv.Windstorms

v.pests and diseases

vi.Landslides

vii.earthquakes 

viii.volcanic eruptions

2. Human activities

i. roads, railway and airport construction

ii.Poaching

iii. pollution

iv.draining of wetlands

v.climate change.

vi.Clearing of land for construction activities

vii.crop production and animal keeping

viii.Introduction of exotic species or invasive species

ix.Overfishing

The extent of loss of biodiversity

It is estimated that the current rate of species extinction to be 100 to 1000 times higher than natural background extinction rate. In the 20th Century alone, 477 vertebrates became extinct. The population of fresh water species have been lost by 83 percent since 1970. Also, out of 96 500 species, 27 percent are threatened by extinction globally.

Effect of loss of biodiversity

i.Environmental degradation

ii.hunger or famine due to the failure of the land to produce enough food

iii.increase in poverty among the people due to failure in agricultural productivity

iv.Drought. This is caused by intensive deforestation.

v.it affects tourism sector. This is caused by death of wild animals

vi.Change of climate

Measures to reduce loss of biodiversity

 (i)Establishment of protected areas

Protected areas such as game reserves prevent people from utilising the areas without permission from the government. These areas include Usangu, Rukwa, Moyowosi, Maswa game reserves and Ngorongoro conservation areas.

(ii)Control environmental pollution: Environmental pollution may affect the survival of various species. Control of environmental pollution is a key to safeguarding aquatic and terrestrial species.

(iii) Provision of environmental education: This is important in influencing human behaviour towards conserving nature and biodiversity protection.

(iv) Control poaching and illegal harvesting: Controlling poaching and illegal harvesting, especially of sensitive species such as rhinos and elephants.

(v) Enacting restricted laws

 

Environmental pollution

Pollution is the release of harmful substances into the environment that can harm living organisms.

Pollutants are harmful substances added to water, air or soil.

Pollutants can be classified as primary and secondary

 i.     Primary pollutants are emitted from the source such as vehicles and industries

ii.     Secondary pollutants are not emitted directly but from the air such as ozone layer.

Causes of environmental pollution

i.Population growth

ii.Industrial activities

iii.Mining activities

iv.Agriculture activities

v.Trnasportation

vi.Uses of bombs and nuclear weapons

CLASSIFICATION OF ENVIRONMENTAL POLLUTION

i.Air pollution

ii.Water pollution

iii.Noise pollution

iv.Land pollution

AIR POLLUTION

Is an addition of waste material into air

Causes of air pollution

Natural causes 

i.Volcanic eruption. That gives out dust ashes and gaseous like sulphur and carbon dioxide.

ii.Wind, storms that raise the dust and pollen to a certain levels. Dust has chemical that are toxic and hence harmful to the living organism both flora and fauna.

 Human causes 

i.Industrial activities and automobile. 

ii.The uses of charcoal, coal, firewood and fuel oil for difference purpose like cooking, lighting, smelting

iii.Construction activities. The construction of project like road construction, salting up buildings and etc. lead to introduction of dust into the air.

iv.Agricultural activities pollute the air through; - Digging in the soil that raises dust into air. -Spraying some chemicals like insecticides.

v. Mining activities: this in also led to the introduction of dust and some gases into the atmosphere.

vi. Military activities such as testing of explosives 

Effects of Air pollution

i. Reduction in amount of solar energy because of being blocked by the layer of dusts or fumes hanging in the atmosphere leading to problems in photosynthesis.

ii. Occurrence of global warming as the result of trapping of heat energy from the sun by the green houses gases. Destruction of Ozone layer.

iii. Death of plants and animals due to poisonous gases.

iv. Climatic change 

v. Occurrence of acidic rainfall when gases like carbon dioxide and Sulphur dioxide mix with rainfall.

vi.It can cause bad and irritating smell keeping people in residence area uncomfortable.

vii. Dangerous disease like Tuberculosis (T.B), or any other respiratory diseases skin cancer due to ozone layer destruction.

Measures towards reducing Air pollution

i. Planting trees which absorb gases like carbon dioxide and prevent fast movement of air that lead to the introduction of dust into the atmosphere and destruction of Ozone layer.

ii. Improving the combination system in the engines so that fuel can burn easily.

iii. Reducing number of small cars or industries.

iv. Finding out alternative sources of energy instead of depending on the charcoal, fire wood, and fuel wood.

v. Government policies should be active and strict laws should be passed to ensure proper management of resources.

vi. Land filling when dumping the wastes so that when they decompose they cannot lead to the emission of gases like methane into the Atmosphere

SOIL POLLUTION (LAND POLLUTION) 

Soil pollution is the process of introducing or adding any unwanted material in the soil.

Causes of soil pollution

i. From the atmosphere: the pollutants are introduced into the soil through the acidic rain. Acid rain leads to the increase of acidity into the soil which later on destroy the soil structure. Acidic rain is predominant in the industrialized countries like Germany Eastern Canada and USA.

ii.From the industries: Some chemical such as radioactive material and metals can be introduced into the soil and render the soil units for Agriculture.

ii. From the home steeds: Some waste from homes like bottles, metallic material plastics. which are dumped into the soil they lead to soil pollution.

iii. From the farms: There are chemicals which include pesticides like DDT crop remains and fertilizers when all these chemicals get into the soil they lead to the soil pollution. Likewise, irrigation activities can lead to soil pollution especially when applied in steep slope areas for a long period of time, the use of Agro chemical.

iv. Mining activities: On the other hands mining activities can lead to the introduction of some rocks. Fragments into the upper layer of the soil which then leads to the soil pollution

Effects of Soil pollution

i.Death of animals (Biota) since some chemicals affect plant and animal cell for instance organism like bacteria which are mainly used for decomposition of some materials to form Humus. (Loss of biodiversity.)

ii.Decline in Agriculture as a results of poor production caused by poor plant growth. Poor plant growth takes place due to the decline in soil fertility in turn to the occurrence of famine which leads to the poor health and death of people.

iii.It can lead to water logging and flooding because of poor drainage caused by the soil pollution which tends to create an impermeable layer of substance in the soil.

iv.Change in soil structure as some of the mineral and nutrients are dissolved by acidic materials.

v.Migration of people to other areas which have not been affected by soil erosion.

vi.Change in soil color which causes problems in the soil classification and determination of land uses.

vii.Decline in other economic activities such as Tourism as it ruin the attractiveness of an area.

viii.Some waste may cause wounding of children by metal and glass broken in the damps. 

ix.Land pollution may lead to diseases as accumulation of wastes on the land may provide habitat to different dangerous organism that cause diseases such as housefly, cockroach, rats.

Measures to be taken in order to reduce the rate of Soil pollution

i. Reducing or stopping the uses of chemicals in agriculture like DDT and used killers.

ii. Increase of manure instead of industrial fertilizers. Method like crops rotation use of organic manure and switch the traditional system like shifting cultivation.

iii. Recycling of wastes rather than dumping them in the soil.

iv. Launching afforestation and reforestation programmers which can reduce soil erosion.

v. Control of population so as to reduce the rate of production of wastes that lead to the pollution of soil. Population control can be done through family planning.

vi. Educating people on how to undertake their activities properly.

vii. Radioactive materials should be dumped so deep in the ground. 

viii. Formulating strict policies that govern on how to dump the wastes. Fines and punishment should be impressed those who dump the waste randomly.

 

WATER POLLUTION

Water pollution; Refers to the addition or introduction of unwanted materials or substances in the water which has negative effect of animal and plant. Polluted water is not fit for human consumption like drinking unit treated first.             

Ways through which Water can be polluted

i. Disposal of untreated sewage into the water bodies. The sewage can be form homestead, Institution like schools, hotels and hospitals.

ii. Dumping of wastes from industries into the water bodies these can be either liquid or solid form.

iii. Some chemicals and other wastes from the farms ear get into the water bodies through the surface turn off or by deliberate dumping by human being leading to water contamination.

iv. Oil spills from the leaking oil containers or pipes. This happened in the Indian Ocean where there are some oil spills from TIPPER in Dar es Salaam in 1990s oil forms a uniform over on the surface of water.

v. Fishing activities, some fishermen tend to use harmful chemicals in fishing which lead to water pollution.

vi. Breaking of rocks along the coastal areas or near other sources of water using explosives like dynamite which in turns leads to the dying of marine organisms including fish.

vii. Introduction of dust into the water sources mainly due to wind action. This is also another way into which water can be polluted.

Effects of Water pollution

  i.          Water pollution can lead to the death of plants and animals if the pollutants and poisonous or causes the rise of temperature to extreme levels.

ii.          Spread of disease like cholera, diarrhea, dysentery and typhoid.

iii.          Oil spills kills aquatic organisms because it prevents oxygen from penetrating into water, organisms die because of lacking oxygen.

iv.          Water pollution leads to the emission of soil smells that causes discomfort to the people round the water body. The soil smell is caused by decomposition of the organic matter introduced into the water body.

v.          Decline of tourist activities due to the fact that tourist who depends on water bodies for swimming will find difficult due to the fact that water bodies has been polluted for example presence of toxic chemicals. ­ The color of water changes. The water becomes under due to the presence of impurities.

vi.          Multiplication of sea weeds as a result of the increase in nutritious from the wastes in water.

vii.          The death of fish leads to the loss of valuable sources of protein to human being (loss of biodiversity).

 

Measures towards Water pollution control

i.Encourage the proper use of fishing methods rather than using chemicals, since chemicals end up killing different fish, animal and plant species.

ii.The oil container and pipes should be kept properly and frequently inspected so as to avoid the problem of soil spiller

iii.Population controlling the population number of people will reduce the amount of water produced.

iv.Reduction in the uses of fertilizers and chemicals in agriculture organic agriculture should be encouraged in which manure is used

ii.The government and the NGO‘S should cooperate in educating people on how to use water, conserve it and where possible they should assist financial in trying to prevent the problem of water pollution.

iii.Water should be kept in a clean containers or reservoirs and be covered flighty to avoid contamination ü Breaking of rocks using dynamite should be discouraged and hence alternative ways should be applied.

iv.Dumping of wastes on the land should be hand in hand with land filling method since random throwing of it leads to water pollution

v.There should be recycling of wastes rather than throwing them into the water bodies.

NOISE POLLUTION

This refers to the disorganized sound produced from different activities.  

 Causes of Noise pollution

i.Transportation activities such as noise from Motor vehicles, motor cycles, trains, aircrafts etc 

ii.Construction activities such as construction of buildings and roads 

iii.Bombing activities (military activities such as explosives and gun fire) 

iv.Machines in factories or industries that disturb neighbors

v.Recreation activities such as night clubs, bars, live concerts, dancing hall.

 

Effects of Noise pollution

i.Mental and physical illness such as deafness

ii.High blood Pressure problem

iii.Death on organism

iv.It distorts sleep and rest 

v.It disrupts daily activities and prevent people from carrying out the works that need concentration

Measures to reduce noise pollution

i.The use of sound-proof facilities

ii.fitting silencers to the exhaust pipes of aircraft and motor-vehicles

iii.applying lubricants to parts of machines

iv.Avoiding unnecessary use of explosives

v.staying away from railway lines, airports as well as roads.

vi.recreational centres should be walled using sound-proof materials.

DESERTIFICATION

Desertification; is the process in which the fertile land is demanded and degraded to produce or initiate desert.

      Causes of Desertification

Human causes

(i)Deforestation

(ii)Overgrazing

(iii)Poor irrigation method

natural causes

(i) Insufficient rainfall; Insufficient rainfall: Desertification could occur in areas where rainfall is low and unreliable. Such areas receive less than 250 mm of rain annually. However, inadequate rainfall can also be caused by human activities such as deforestation

(ii) High temperature; Areas experiencing high temperature tend to have a high rate of evaporation. If the rate of evaporation exceeds the rate of precipitation, there would be moisture deficiency in the soil. This affects vegetation and other living organisms

(iii) Cold ocean currents; Onshore winds cross over cold ocean currents and then drop most of the rainfall over the sea and reach the land as dry wind. This effect is experienced on the western coasts of South Africa due to the influence of the cold ocean current called Benguela.

(iv)  Relief barrier; Land situated on the leeward sides of the mountain are usually dry because of the rain shadow effect of the mountain

(v)  Distance from the sea; Places located in the interior of continents are far from the effects of onshore moist wind

(vi)  Wind system; Dry wind originating from the interior of continents can contribute to desertification of the region over which they blow

(vii) Pressure system; Regions with low humidity and descending air masses have no rainfall because rain is caused by ascending and not descending air.

 

Effects of Desertification

i. It leads to decline in economic activities such as agriculture. 

ii. Migration of people from affected area to productive land area. 

iii. Acceleration of soil erosion which leads to deforestation and loss of arable land

iv. water scarcity makes travel long distance in search for water for domestic uses like cooking, drinking, washing.

v. Destruction of wild life animals and species 

vi.Loss of bio diversity (disappearance of some species of plants and animals)

vii.Climatic change such as drought.

 

Measures to be taken in order to minimize the rate of Desertification

i.Alternative source of energy should be used in the developing countries especially in natural areas where the majority live. Alternative energy includes solar energy, wind power, bio gas and hydroelectric power

ii.The local people should be educated on how to conserve vegetation. Some programs like afforestation and reforestation should be encouraged in order to mitigate them.

iii.The government should advice some substantive policies whose objectives are to lay down principles to guide development and control of forests.

iv.The government should encourage forest conservation by avoiding deforestation.

v.To encourage sustainable human activities such as proper mining, proper agricultural activities and destocking. 

vi.To perform land reclamation projects in the arid areas so as to turn them into productive land. 

 

Land degradation

Land degradation refers to the deterioration of the quality of land through the loss of soil fertility, soil pollution and other natural processes like landslides.

 

Cause of land degradation

Human causes

    i.            Poor farming practices: These refer to excessive use of chemical fertilisers, and pesticides and over-cultivation. Monoculture may affect the quality of land or soil through exhaustion, which in time lowers its quality to support agricultural production.

  ii.            Deforestation: Deforestation also accelerates land degradation. Forests play an important role in maintaining fertility of soil by shedding their leaves, which contain many nutrients. Also, forests help to bind the soil particles together

 iii.            Mining activities: Mining activities cause land degradation. When minerals are extracted from the land many holes left behind collapse, especially in the open cast mining. For example, Bulyanhulu and Buzwagi gold mining centres in Kahama-Shinyanga and Geita mining centre in Geita.

 iv.            Industrial activities: Another cause of land degradation is industrial wastes as when dumped on the Earth's surface, they destroy soils and, thus, become unfit for agriculture and settlements. For example, the dump site located at PuguKinyamwezi in Dar es Salaam

  v.            Population pressure: Population pressure which causes excessive use of the available land resources may accelerate land degradation. This means the land will be over utilised hence become exhausted. Acidic rainfall:

 vi.            Acidic rainfall, which is formed from Sulphur dioxide and nitrogen oxide emitted by thermal power stations, industries, motor vehicles and burning coals, leads to an increase in acidity on land, hence causing soil infertility.

Natural causes

                i.            Landslides

              ii.            Floods

             iii.            Earthquakes

Effect of land degradation

         i.            deterioration in the chemical and physical properties of soils

       ii.            decline of biodiversity

     iii.             increase in hazards for human occupation

     iv.            food shortage.

       v.            Land degradation leads to migration of people to other places, which are still conducive for agricultural production and the cost to rehabilitate the degraded land is usually very high.

Measures to reduce land degradation

         i.            Practising proper agricultural methods, for example, agroforestry, the use of terraces on slopes and the use of minimal tillage to avoid soil erosion.

       ii.            Encouraging people to practice afforestation and reforestation can also help to control land degradation.

     iii.            Enforcement of laws and rules that guide the proper land utilisation to avoid its misuse and

     iv.            provision of mass education to create awareness to people through meetings, seminars, and the mass media

Environmental hazards

 A hazard is a danger that may result in the destruction of mankind and his or her property in his or her environment. It is something which is known to cause harm to the environment. For example, floods and drought.

A hazard is something which is known to cause harm, that is, a source of danger to health,

whereas a risk is the likelihood or probability of the hazard occurring and the magnitude of the resulting effects.

 

The conditions or the situation of making cow-dung cake near the houses for getting fuel is hazardous (or dangerous) because it facilitates the breeding of flies in our environment. The infected food is a hazard that can damage a child’s health. The risk of getting an infection is very high if we live in a contaminated environment.

 

Categories of environmental hazards

i.            physical hazards; Physical hazards are those substances or conditions that threaten our physical safety. Fires, explosive materials, temperature (hot or cold), noise, radiation, spills on floors and unguarded machines are some examples of physical hazards.

ii.            biological hazards; Biological hazards are organisms, or by-products from an organism, that are harmful or potentially harmful to human beings. They include pathogenic bacteria, viruses and parasites, and toxins (poisons) that are produced by organisms. Biological hazards are the main causes of most of human diseases. Examples of these diseases are cholera, tuberculosis, leprosy, relapsing fever and many diarrhoea related diseases.

iii.            chemical hazards; These are present when a person is exposed to a harmful chemical at home, street or at work. The chemicals can be in the form of gases, solids or liquids. Exposure to chemicals could cause acute health effects (an immediate or rapid onset) if taken in wrongly and large quantities in a single dose; and chronic health effects (long-term effects on health) if taken in wrongly and small doses over an extended time. Detergents (powdered soap, bleaching agents), drugs (veterinary and human) and pesticides are chemical hazards that are commonly found in rural households.

iv.            cultural or practice-related hazards; Culture is the knowledge, belief, art, law, morals, customs and habits that are acquired by people as members of the community. There are practices that are widely practised in different areas of Tanzania, which are hazards to human health. For example, the belief that evil spirits are the source of diseases, practices of storing drinking water uncovered, open defecation, and eating without washing hands.

Impact of poverty on environment

i.Depends on biomass

ii. Ignorance.

iii.Poor method of farming

iv. Poor waste management

v.Deforestation

vi. Over grazing

 

Population and urban growth and their effects on environment

Causes of rapid population growth

    i.            Migration

  ii.            Birth rate

 iii.            Death rate

Consequences of rapid population growth on environment

    i.            Global warming: The rapid population growth leads to global warming. Energy production through power plants and burning of fossil fuel needed to support human life increases the emission of greenhouse gases which lead to rising global temperatures

  ii.            Deforestation: Deforestation results from rapid population growth. To support the growing population, forests are cleared and destroyed at an alarming rate for agriculture and human settlements

 iii.            The depletion of non-renewable resources. Increased population translates into increased demand for resources, thus resource depletion.

 iv.            Pollution: Rapid population growth causes envirnmental pollution. For instance, air pollution resulting from the use of fuelwood, which are environmentally-unfriendly. Water pollution may occur due to excessive utilisation.

  v.            Solid and liquid waste disposal: Rapid population growth increases the production of solid and liquid wastes. In case these are not properly managed, they pollute the environment.

 vi.            Environmental degradation: In some areas, people depend on biomass fuel such as cow-dung, fodder and crop residues because of scarcity of fuel wood.

Causes and consequences of global climatic change on environment

CLIMATIC CHANGE

Refers to long term shifts in temperature and weather pattern.

This shift can be caused by human and natural factors

 

Causes of climatic change

Human causes

    i.            Industrial activities.

it leads to emission into and concentration of greenhouse gases such as carbon dioxide in the atmosphere. Nearly one-third of human-induced nitrous oxide emissions result from industrial activities. Chlorofluorocarbon (CFCs) and other greenhouse gases that stem from industrial activities have a powerful warming effect due to their heat trapping abilities in the atmosphere.

  ii.            The use of fossil fuels and burning of vegetation release carbon into the atmosphere

 iii.            Agricultural and mining activities. The concentrations of methane gases have also risen due to cattle rearing, cultivation of rice as well as release from landfills.

 iv.            Transportation activities also contribute to climate change. With an alarming growth of population, the demand for transport means also increases. When vehicles, ships and airplanes are used for transportation, the emission of carbon dioxide into the atmosphere also increases, hence causing the concentration of greenhouse gases, which adversely lead to climate change.

  v.            Deforestation. The permanent removal of trees without replacement for various purposes such as lumbering, extraction of logs, settlement and sports fields contribute to climate change.

 

Natural causes

         i.            Volcanic eruption

Volcanic eruption emits harmful gas such as carbon dioxide and Sulphur dioxide. These gases absorb reflected sun rays from the sun. these gases become as glass that store heat, the increase of heat lead to increase of temperature over the world.

       ii.            Solar output and distance of the earth from the sun

     iii.            Changes in oceanic circulation

Refers to exchange of heat between ocean and atmosphere. This changes occurs from poles to the equator due to difference of distance from the sun.

     iv.            Increase of greenhouse gases

 

Consequences of climate change on the environment

         i.            Heavy rainfall

       ii.            Loss of biodiversity.

     iii.            The changes in temperature leads to butteries, foxes and alpine plants moving or shifting further north to higher and cooler areas

     iv.            Destruction of properties

       v.            Lack of clean and safe water

     vi.            Decline of agriculture activities.

 

Drought

This is a state of an area facing a prolonged condition of dryness without precipitation or a long period of dry weather. Singida, Dodoma, Shinyanga and Kondoa.

 

Causes of drought

Natural causes

         i.            Wind system is one of the causes of drought. When the wind blows across narrow water mass, it causes drought as it carries less moisture for rain formation.

       ii.            Aspect. Places located in the leeward side of mountains tend to experience dryness due to being in a rain shadow. Moist wind from another side of the mountain is obstructed by one side of the mountain.

     iii.            Natural fire. Fire resulting from natural hazards such as lightning and volcanic eruption may destruct largescale of vegetation leaving the land bare, hence unstable.

     iv.            The apparent movement of the Sun and shifting of the overhead Sun to other places also lead to rainfall regime shift. When the Sun shifts to the Northern Hemisphere, dryness occurs in the Southern Hemisphere and vice-versa.

Human causes

         i.            Lumbering

       ii.             Poor agricultural practices such as shifting cultivation

     iii.            Mining activities

     iv.            Over cultivation

 

Effect of drought

          i.            Intensify desertification

         ii.            Decline of agriculture activities

       iii.            Shortage of water supply

       iv.            Occurrence of hunger and famine

         v.            Poor supply of power and energy. This is caused by lack of water for producing hydroelectric power.

Measures to reduce drought

         i.            Provision of education concern water conservation

       ii.            Establishment of water resources scheme

     iii.            Prevention of forest resources through avoiding deforestation.

     iv.            Proper farming system, avoiding shift cultivation practice.

       v.            The use of alternative source of energy

Ozone layer depletion

The ozone layer is an isotope of oxygen (O₃) whose concentration zone is in the stratosphere.

The ozone layer is important because it protects the Earth from the damaging effects of ultra-violet radiations from the Sun. The ozone layer absorbs such radiations. When ozone depletingsubstances such as chlorofluorocarbons (CFCs) react with ozone they result in oxygen (O2 ) and oxygen atom (O). Such reaction depletes the ozone layer, hence reducing its capacity to filter ultra-violet rays.

 

Causes of depletion of the ozone layer

Air pollution with gases such as Chlorofluorocarbons, Carbon monoxide and methane deplete the ozone layer leading to the formation of holes. These holes allow free passage of ultra-violet rays from the Sun, hence damaging plant tissues and causing cancer in human beings.

Effects of destruction of ozone layer

         i.            The increase of incidents of skin cancer

       ii.            The Ozone layer depletion leads to the death of some plants and animal species. Overall, the unfiltered ultra violet radiation from the Sun comes directly to the Earth's surface without being filtered because of Ozone layer depletion.

     iii.            Increase of temperature in the world

     iv.            Drought

 

5.4 Environmental conservation

a.       Define Environment conservation

b.       Analyses various ways of conserve environment

c.       Practice environmental conservation and management at school level.

 

Environmental Conservation is protection and maintenance for sustainable use of natural resources such as minerals, soil, forests and wildlife.

 

Ways of conserving environment

         i.            The use of alternative source of energy

       ii.            Protection of catchment area

     iii.            Re-use or recycling of wastes such as bottles

     iv.            Allowing private sectors to co-ordinate matters related to environmental conservation

       v.            Provision of education

     vi.            Soil conservation

    vii.            Proper method of farming

Examples of proper method of farming which protect soil from being eroded.

a.       Terracing This method is normally practised on slopes in which the land is cut into a series of wide steps (terraces), on which the crops are grown Normally, there are deep furrows between terraces which allow water to penetrate deep instead of water running off on the ground

b.       Planting of shelterbelts trees

Belts of trees are planted across a flat region, which is liable to suffer from wind erosion. Trees act as wind-breakers.

c.       Crop rotation This farming method is done by rotating different types of crops in different seasons to maintain soil fertility. Crop rotation ensures that the soil remains fertile and does not lose its texture and nutrients.

d.       Bush fallowing This is practised by cropping on new plots and former plots are left for some years for the purpose of restoring their fertility.

e.       Mulching This is the action of spreading dry grasses and leaves over the surface of the soil to prevent evaporation. It also maintains soil fertility when grass or leaves decompose.