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ENVIRONMENTAL ISSUES AND MANAGEMENT

Thursday, April 25, 2019

The Concept of Environment

Environment
Explain the meaning of environment
In geography, the term ‘environment’ refers to the totality of the natural world, often excluding humans. The ‘natural word’ means the sum total of all surroundings of man, including nonliving things, natural forces and other living things.
So you can see that environment is everything that is around us. It can be living or nonliving things. It includes physical, chemical and other natural forces.
Living things live in their environment. They constantly interact with the environment and change in response to conditions in their environment. There are interactions between animals (including humans), plants, soil, water, and other living and non-living things.
Since everything is part of the environment of something else, the word ‘environment’ is used to talk about many things. People in different fields of knowledge (like history, geography or biology) use the word environment differently.
In biology and ecology, the environment is all of the natural materials and living things, including sunlight. If those things are natural, it is a natural environment.
In history, a person’s environment is the events and culture that the person lived in. A person's beliefs and actions depend on his environment.

The Importance of Environment

Explain the importance of environment
Environment is the key for existence of life on the Earth. All living organisms on Earth depend on the environment for survival. We should always strive to manage and conserve our environment. It matters because Earth is the only home that humans have, and it provides air, food, and other needs. The environment is important for the following reasons:
General life support
The environment contains all the resources which sustain life. These resources include soil, air, and water. The soil contains water and mineral nutrients which support plants on which humans and other animals feed. Without soil there would be no food. Even the animals that are eaten by man such birds, cattle, etc. feed on plants that grown on the soil. The increasing human population need food to survive. It is therefore important to ensure the soil is productive enough to produce enough food to feed the ever-increasing human population.
Air, as a part of the environment is needed by all organisms on Earth, including those that we cannot see with our naked eyes (microorganisms). Air is essential for life and no organism can survive without it. A constant supply of fresh air is very important though in recent years, air pollution has been a big problem, especially in heavily industrialized countries. Air pollution denies us clean air and also makes the Earth excessively hot, a condition known as global warming.
Natural beauty
Another reason the environment is so important is because it is a source of natural beauty. People enjoy nature for recreation, tourism, and sports such as skiing in snow or rafting. The physical landscape, drainage features, plants and animals are beautiful to look at in their natural settings. Nature is considered necessary for proper physical and mental health too.
Unfortunately the planet is in danger. Many species of animals and plants are nearing extinction, and more and more beautiful, open spaces are disappearing as new buildings and factories are built.
Natural resources
The environment contains diverse natural resources. The most important natural resources and products derived from the environment include the following:
  • Water - Water is an important resource needed for survival of all living organisms.
  • Medicines - Many plants have been used as medicines for hundreds of years, and are even now exploited by modern pharmaceuticals.
  • Clothing - Clothes are produced from plants like wood pulp, cotton, hemp, jute or animal products like silk, wool, and leather. In addition, synthetic clothes are produced from petroleum products.
  • Wood - Wood from forests or plantations is used as fuel, in construction and for making furniture.
  • Biofuels - Biofuels, like bioethanol, are extracted from wheat, corn or biomass crops like jatropha.
  • Fossil fuels - Fossil fuels, such as coal, gas and crude oil used in transportation, energy generation and production of plastics and chemicals, depend on dead plant and animal biomass produced by previous ecosystems that are stored and accumulated over millions of years on Earth.
Quality of Air
Trees produce oxygen during photosynthesis. In addition, during this process trees also use carbon dioxide in the air and reduce its concentration in the atmosphere. This process regulates and maintains the carbon cycle. Trees can also remove pollutants from the air.

Environmental Problems

Identify environmental problems
Environmental problems refer to known processes (such as resource consumption) that have negative effects on the sustainability of the environmental quality necessary for the well being of the organisms living in it. Some scholars define environmental problems as problems caused by environmental changes due to human activities that greatly endanger the well-being of humans and the balance of our ecosystem.
The main environmental problems facing the Earth include the following:
  1. Pollution
  2. Overpopulation
  3. Global warming
  4. Waste disposal
  5. Climate change
  6. Loss of biodiversity
  7. Desertification
  8. Ocean acidification
  9. Ozone layer depletion
  10. Acid rain
  11. Natural disasters
  12. Overgrazing

The Causes, Extent and Effects of the Loss of Biodiversity

Analyse the causes, extent and effects of the loss of biodiversity
Loss of biodiversity
Biodiversity or biological diversity is a term that describes the variety of living things on Earth. Biodiversity also refers to the number, or abundance of different species living within a particular region. It represents the wealth of biological resources available to us.
Loss of biodiversity or biodiversity loss is the ongoing reduction or extinction (entire loss) of species worldwide, and also the local reduction or loss of species in a certain habitat or ecological niche or biome. It also refers to the disappearance of different plants and animal species in a particular geographical unit or community.
Causes of loss of biodiversity
The Earth’s biodiversity is in grave danger. The causes of loss of biodiversity can be either natural or human causes. These causes are summarized in the following main points:
Natural causes
These occur without human intervention. They are mainly caused by natural forces such as Earthquakes, landslides, lightning, and volcanic eruptions. Some of the natural causes of loss of biodiversity include the following:
  1. Floods which kill many organisms (plants and animals) where they occur.
  2. Lightning in which organisms die due to natural electricity.
  3. Wind storms, where strong winds uproot and break plants, and cause massive death of organisms.
  4. Pests and diseases occurring at exceptionally high rates tend to kill large numbers of organisms.
  5. Landslides and other types of mass wasting, vulcanicity, glaciation and Earthquakes tend to kill organisms in large numbers whenever they occur.
Other ecological factors that may also contribute to the extinction of plant and animal diversity are as follows:
  1. Distribution range: The smaller the range of distribution, the greater the threat of extinction.
  2. Degree of specialization: The more specialized an organism is, the more vulnerable it is to extinction.
  3. Position of the organism in the food chain: The higher the organism in food chain, the more susceptible it becomes.
  4. Reproductive rate: Large organisms tend to produce fewer offspring at wide time intervals, e.g. elephants. Elephants are at a greater threat of extinction compared to prolific animals with high reproductive rates like rats.
Human causes
The main cause of the loss of biodiversity can be attributed to the influence of human beings on the world’s ecosystem. In fact, human beings have deeply altered the environment, and have modified the territory, exploiting the species directly, for example by fishing and hunting, changing the biogeochemical cycles and transferring species from one area to another of the planet. Often, the terms threatened, endangered or rare are used to describe the status of many species. Human activities which lead to loss of biodiversity include the following:
1. Destruction of habitats
The natural habitat may be destroyed by man for his settlement, agriculture, mining, industries, highway construction, dam building, etc. As a consequence, the species must adapt to the changes in the environment, move elsewhere or may succumb to predation, starvation or disease and eventually die.
3. Introduction of exotic species
Species originating from a particular area, introduced into new natural environments can lead to different forms of imbalance in the ecological equilibrium.
The introduction of new species increases competition amongst locals and often leads to extinction of native populations. In much of the world, this is happening on farms, too, where foreign breeds of cattle are being imported, pushing out natives.
This means that the world's livestock population is becoming increasingly narrow; and more vulnerable to disease, drought, and changes in climate. The ultimate result of the narrowing of livestock population is the loss of biodiversity and extinction of species.
4. Pollution
Human activities influence the natural environment producing negative (direct or indirect) effects that alter the flow of energy, the chemical and physical constitution of the environment and abundance of the species.
5. Overexploitation of resources
When the activities connected with capturing and harvesting (hunting, fishing, farming) a renewable natural resource in a particular area is excessively intense, the resource itself may become exhausted, as for example, is the case of sardines, herrings, cod, tuna and many other species that man captures without leaving enough time for the organisms to reproduce.
Wild animals are hunted for the commercial utilization of their products such as hides and skins, tusks, furs, meat, pharmaceuticals, cosmetics, perfumes and decoration purposes. In Africa, in recent years 95% of the black rhino population have been exterminated in Africa by poachers for their horn.
6. Climate change
As climate change alters temperature and weather patterns, it will also have an impact on plant and animal life. Both the number and range of species, which define biodiversity, are expected to decline greatly as temperatures continue to rise.


7. Habitat fragmentation
Habitat fragmentation may be defined as an unnatural detaching or separation of expansive tracts of habitats into spatially segregated fragments that are too limited to maintain their different species for an infinite future.
8. Control of pests and predators
Predator and pest control measures, generally kill predators that are a component of balanced ecosystem and may also indiscriminately kill non-target species.
Extent of loss of diversity
A great number of human activities are affecting the environment negatively leading to pollution and climate change. It has been observed that some species have already become extinct and a large number is threatened with extinction. This has lead to increased concern for environmental protection and conservation.
Effects of loss of biodiversity
The loss of biodiversity has many effects to humans. Some of these effects are explained below:
Reduced food security
Loss of biodiversity leads to the loss of the green economics. It occurs when the plants and other organisms of similar properties to plants are lost. This, in turn, leads to failure of organisms to make carbohydrates, proteins and lipids that are needed for the survival of all organisms on Earth.
Likewise, loss of biodiversity leads to extreme weather events, a situation which is hazardous to all organisms still existing on Earth. This leads to failure of agriculture that is essential in sustaining life.
Environmental degradation
Environmental degradation makes the biosphere to be hostile to organisms. Pollution of water, land and air make these environments uninhabitable or nearly uninhabitable to organisms. Vegetation loss through human activities leads to desertification and its consequent negative effects. This further leads to loss of land for agriculture and settlements.
Loss of habitats
Destruction of vegetation, artificially by man or naturally by other natural forces, leads to destruction of not only plants per se but also the habitats of many organisms living in there. Thus, organisms are deprived of their natural habitats and forced either to adapt to new conditions or become more exposed to predators.
Effect on human health
Human health ultimately depends upon ecosystem products and services (such as availability of fresh water, food and fuel sources) which are necessary for good human health and productive livelihoods. Biodiversity loss can have significant direct human health impacts if ecosystem services are no longer adequate to meet social needs. Indirectly, changes in ecosystem services affect livelihoods, income, local migration, and may even cause political conflict.
Significant medical and pharmacological discoveries are made through greater understanding of the Earth's biodiversity. Loss in biodiversity may limit discovery of potential treatments for many diseases and health problems.
Increased contact with disease
The loss of biodiversity has two significant impacts on human health and the spread of disease. First, it increases the number of disease-carrying animals in local populations. Research has shown that the species best adapted to survive critically in fragmented habitats are also the most prolific carriers of pathogens. As habitats are broken apart and reduced in size, these animals become more common, winning out over the species that do not typically transmit the disease.
Secondly, habitat fragmentation brings humans in closer and more frequent contact with these disease-carrying species.
Depreciation of aesthetic value
Loss of biodiversity leads to depreciation in aesthetic value of the environment. People are deprived of the happiness they get from the environment. The enjoyment they get by looking at beautiful vegetation, natural landscapes and wild animals is all lost.
More unpredictable weather
The loss of species, even those replaced by invasives, has been shown to cause more unpredictable weather.
The Causes, Extent and Effects of Pollution and Waste Mismanagement
Analyse the causes, extent and effects of pollution and waste mismanagement
Pollution is the introduction of contaminants into the natural environment that causes adverse change. Pollution can take the form of chemical substances or energy, such as noise, heat or light. Pollutants, the components of pollution, can be either foreign substances/energies or naturally occurring contaminants.
Waste management or waste disposal includes all the activities and actions required to manage waste from its creation to its final disposal. This includes, amongst other things, collection, transport, treatment and disposal of waste together with monitoring and regulation. It also includes the legal and regulatory framework that relates to waste management.
The term normally relates to all kinds of waste, whether generated during the extraction of raw materials, the processing of raw materials into intermediate and final products, the consumption of final products, or other human activities. Waste management is intended to reduce adverse effects of waste on health, the environment or aesthetics.
Waste management practices are not uniform among countries (developed and developing nations); regions (urban and rural area), and sectors (residential and industrial).
Forms of pollution
There are various forms of pollution which include land, water, air and noise pollution. The causes of each of these forms of pollution are explained below:
Causes of land (soil) pollution
The causes of land pollution are mainly manmade and one that can be controlled. They include the following:
  1. Agrochemicals: The overuse of agrochemicals (such as agricultural fertilizers, herbicides and pesticides) results in the contamination and poisoning of the soil.
  2. Mining activities: Mining involves the use of toxic chemicals that are used for mineral separation. When these chemicals drain into the soil, it gets polluted. Mining also causes large depressions or holes on the ground into which rain water may accumulate to form ponds. Such a land is unsuitable for agriculture, settlement or undertaking any other human activities.
  3. Waste disposal: Humans deliberately dump wastes such as sewage, garbage, industrial effluent and used oil on the land thereby contaminating the soil with the toxic chemicals contained in these categories of wastes.
Causes of water pollution
Water pollution includes contamination of water with dust and salt which are added to water bodies through erosion and deposition by wind and running water. It is also caused by human activities which include the following:
  1. Agrochemicals: Chemicals used in agriculture drip onto the soil and may eventually run off into the local streams and rivers.
  2. Oil spills: Accidental and deliberate disposal of oil waste and other products into the water sources.
  3. Sewage: In developing countries about 90% of untreated sewage is discharged directly into rivers and streams.
  4. Marine debris: The debris mainly comes from urban water and garbage thrown overboard from ships and boats.
  5. Sediment: The increased amount of sediment running off the land into nearby water bodies seriously affects the fish and other aquatic life.
Causes of air pollution
The following are the chief causes of air pollution:
  1. Exhaust smoke from industries and motor vehicles.
  2. Dust from wind storms, excavation works and mines, agricultural activities and constructions.
  3. Gases produced from burning of fossil fuels produces gases that pollute the environment. These gases include sulphur dioxide, carbon dioxide, carbon monoxide, and nitrogen oxides.
  4. Chlorofluorocarbons (CFCs).
  5. Volcanic eruptions.
Causes of noise pollution
Noise pollution is a disturbing noise with harmful impact on the activity of human or animal life. It can also be defined as an undesirable sound or sound which generates horrible discomfort on the ears. The causes of noise pollution include the following:
  1. Sound of traffic with the roaring engines of trucks, buses, motorcycles and constant humming of cars.
  2. High-pitched sound from trains and aircrafts.
  3. Loud machinery in industries, factories and construction sites.
  4. Loud tools such as wood cutting tools, welding tools, generators, lawnmowers and other gardening and cleaning machinery.
  5. Listening to music with head phones or played in a band or music concerts.
  6. Loud speakers and amplifiers used at large gatherings of celebrations or protests.
  7. Sudden or constant intense sounds like the one experienced in war zones or in mines during rock blasting.
Effects of environmental pollution
The effects of environmental pollution include the following:
  1. Wastes dumped carelessly can endanger the health of man as well as other organisms. Empty cans, glass and plastic containers are potential breeding grounds for mosquitoes which spread malaria and other diseases. Rotten organic matter may harbour many disease germs and they also produce noxious smell when they rot. The rotten wastes also attract flies which transmit a number of enteric diseases like dysentery, cholera, and diarrhoea.Contaminated water is a source of waterborne diseases such as typhoid, diarrhoea, dysentery, cholera, bilharzia and many other diseases caused by bacteria, parasites and viruses. Contaminated water also spread intestinal parasites such as hook warm, round worms, and ascaris.Exposure to air pollutants can cause serious health problems. Long-term health effects of air pollution include chronic respiratory diseases, lung cancer, heart diseases, and even damage to the brain, nerves, liver or kidneys.
  2. Land pollution causes chemical contamination and loss of ecosystem. This occurs when the chemicals in the waste matter poison the soil. The plants growing on the poisoned soil, animals that eat these plants and even humans are all affected by these chemical contaminants. This process is called biomagnification and is a serious threat to the ecology. It can lead to the loss of some types of plants and animal life as well as create long-term health problems such as cancer in humans and other deformities. Radiation from nuclear wastes causes healthy problems such as cancers and other deformities.
  3. Deforestation causes imbalance in the rain cycle. A disturbed rain cycle affects a lot of factors such as reduction in the green cover. Plants help absorb excess carbon dioxide from the air and release oxygen to the atmosphere. This process helps to balance the atmosphere. Without vegetation cover, excessive accumulation of carbon dioxide in the atmosphere causes concerns like global warming, the greenhouse effect, irregular rainfall and floods, among other imbalances.
  4. Terrestrial pollution is a big problem in urban areas where waste production outweighs waste disposal. In such areas you find poor and blocked sewage system, effluent from domestic toilets flowing on the streets and roads, and dirty water carelessly poured on the ground. This makes life in urban areas uncomfortable and a mere nuisance.
  5. Chemicals discharged into water bodies have direct toxic effects on aquatic life. These chemicals include pesticides, oil spills, mercury, and industrial chemicals. They can kill fish for many kilometres downstream.Discharging the hot water from a power plant into a river could affect aquatic organisms greatly. Even a small increase in temperature can kill organisms from thermal shock. Also the extra heat may disrupt spawning or kill young fish.A high temperature warms the water and lowers the amount of oxygen that can dissolve in that water. This causes the aquatic organisms to increase their respiration rates. All this increases the aquatic organisms’ susceptibility to disease, parasites and the effects of toxic chemicals.Global warming also causes extra heat to the oceans, leading to similar effects explained above.
  6. Noise pollution disturbs both man and other animals. It leads to problems such as noise-induced hearing loss, headaches and fatigue due to disturbed sleep patterns, hypertension and cardiovascular disease such as myocardial infarction and increases stress leading to psychological disturbance. The effect on animals that are sensitive to sounds beyond the capacity of human years is also noted. This is expressed in terms of fear, increased aggression and changes in normal physiological or bodily functions such as hunger, urination, defecation, pacing, etc.Noise pollution from various ship engines and sonar systems make it difficult for marine organisms like whales, dolphins, and porpoises to communicate, find food and avoid hazards. Excessive noise pollution may cause damage to marine animals’ sound-sensitive organs. This can cause internal bleeding and even death.
  7. One of the effects of air pollution is global warming. Greenhouse gases in the atmosphere allow ultraviolet radiations to pass through them and reach the Earth. As the Earth’s surface gets heated up, some of the heat is radiated back to the atmosphere. A layer of the greenhouse gases in the atmosphere, acting as a blanket, prevents the heat from escaping to the upper atmosphere. This causes excess heat in the air around the Earth (atmosphere), a phenomenon called global warming.
  8. Air pollution causes depletion of the ozone layer. The ozone plays an important role in absorbing dangerous ultraviolet radiation emitted by the sun. These radiations are dangerous as they cause diseases like cancer in organisms, including man.
  9. Human activities explained previously produce harmful gases such as oxides of nitrogen and sulphur which are released into the atmosphere. These gases are responsible for the formation of acid rain. Acid rain damages plants and corrodes many ancient buildings, monuments and sculptures made of marble. It greatly affects the aquatic life due to the acidification of lakes and streams.
  10. Air pollution by smoke causes smog which reduces visibility, making activities such as driving, surveying and flying difficult. However, this problem mostly affects heavily industrialized countries because of excessive production of gases from industries and automobiles.

The Causes, Extent, Effects of Fast Rate of Population and Urban Growth on Environment

Explain the causes, extent, effects of fast rate of population and urban growth on environment
In the previous chapters on human population and settlements we learned in detail about the extent and causes of rapid population and urban growth. The following is a reminder of the causes of the fast rate of population and urban growth.
Causes of the fast rate of population growth
The rapid growth of the world’s population over the past one hundred years results from a difference between the rate of birth and the rate of death. The growth in human population around the world affects all people through its impact on the economy and environment.
The current rate of population growth is now a significant burden to human well-being. Understanding the factors which affect population growth patterns can help us plan for the future. Causes of overpopulation include the following:
(a) Decline in the death rate
The fall in death rates, that is, a decline in mortality rate is one of the fundamental causes of overpopulation. Owing to the advancements in medicine, man has found cures to the previously fatal diseases. The new inventions in medicine have brought in treatments for most of the dreadful diseases. This has resulted in an increase in the life expectancy of individuals. Mortality rate has declined leading to an increase in population.
Owing to modern medications and improved treatments to various illnesses, the overall death rate has gone down. The brighter side of it is that we have been able to fight many diseases and prevent deaths. On the other hand, the medical boon has brought with it, the curse of overpopulation.
(b) Rise in the birth rate
Thanks to the new discoveries in nutritional science, we have been able to bring an increase in the fertility rates of human beings. Medicines of today can boost the reproductive rate in human beings. There are medicines and treatments, which can help in conception. Thus, science has led to an increase in birth rate. This is certainly a reason to be proud and happy but advances in medicine have also become a cause of overpopulation.
(c) Migration
Immigration is a problem in some parts of the world. If the inhabitants of various countries migrate to a particular part of the world and settle over there, the area is bound to suffer from the ill effects of overpopulation. If the rates of emigration from a certain nation do not match the rates of immigration to that country, overpopulation makes its way. The country becomes overly populated.
(d) Lack of education
Illiteracy is another important cause of overpopulation and lack of family planning is commonly seen among the illiterates. Those lacking education fail to understand the need to prevent excessive growth of population. They even don’t know the harmful effects of overpopulation.
They are unaware of the ways to control population. This is one of the major factors leading to overpopulation. Due to ignorance, they do not take family planning measures, thus contributing to a rise in population.
Causes of the fast rate of urban growth
Urban areas are growing faster in LEDCs than anywhere else in the world, but this growth brings problems and challenges, all of which require good management and solutions.
Although the process of urbanisation happens in both MEDCs and LEDCs, the fastest-growing cities in the world are in LEDCs.
The reasons for the growth of urban areas include the following:
  1. A lack of employment opportunities in the countryside is among the driving forces of urban growth. Overpopulation and poor crop yields are all push factors that make people leave the countryside and move to urban areas.
  2. Better paid jobs in the cities, an expected higher standard of living, and more reliable food attract people to the city.
  3. People who migrate to towns and cities tend to be young and so have higher birth rates in that age range.
  4. Better medical conditions compared to the countryside mean more successful births and a better life expectancy.
Effects of fast rate of population and urban growth on the environment
One of the factors responsible for environment degradation is population growth or population density and urban growth. This is because the growing population demands more and more (non-renewable) resources for its own application. The environmental problems associated with the rapid population and urban growth includes the following:
Accumulation of waste
Due to overpopulation, the rate of generating waste is higher than it can be removed by the local council, city or municipal authorities. Difficulty in dealing with urban waste leads to environmental pollution. A lot of piles of waste are found scattered here and there in many urban centres among the LEDCs. Such a situation is a potential threat to public health because dirt is the major breeding ground of germs that cause various diseases such dysentery, typhoid, diarrhoea and cholera. The accumulated waste also produces a bad smell which pollutes the air.
Deforestation
Fast population growth leads to an increase in demand of land for settlement and agriculture. As a result, more land is cleared to establish agriculture as well as settlements. Further clearing of the vegetation can lead to desertification and climate change. That is why amount and frequency of rainfall in urban areas has shown a great fluctuation in the past few decades.
Soil and water pollution
To feed the ever-growing human population, farmers use diverse agrochemicals to produce more food to feed the population. Excessive use of agrochemicals pollutes the soil and destroys soil structure. Soil microorganisms are also killed. As a result, the soil fertility is curtailed a great deal.
As the farmers struggle to produce more food using a limited land resource, some tend to grow crops near water sources. This leads to pollution of water via the eroded soil and agrochemicals. Likewise, due to land scarcity, people live very close to water sources such as rivers, streams and lakes. The closer the settlements are to water sources, the more likely they can pollute the water.
Loss of biodiversity
Due to his destructive activities, man has extracted more and more minerals from the Earth. Animals have been hunted and plants have disappeared. There has been a loss of biodiversity which has led to ecological imbalance.
Climate change
The gases produced by industries and automobile exhausts accumulate in the air and cause greenhouse effect which contributes to global warming with its adverse effects to the environment and living organisms, including humans.

The Causes, Extent and Impacts of Desertification

Examine causes, extent and impacts of desertification
Desertification is a type of land degradation in which a relatively dry area of land becomes increasingly arid, typically losing its bodies of water as well as vegetation and wildlife. Or, to put it another way, desertification is the process by which previously biologically productive land is transformed into wasteland. It is the sum of all environmental processes which result in the formation of a desert.
Causes of desertification
Climatic variations and human activities can be regarded as the twobroad causes of desertification. The major causes of desertification include the following:
Overgrazing
In arid regions, grass and other vegetation is necessary to keep the soil in place. If the vegetation is overgrazed by livestock, there is very little or no vegetation that remains to prevent the soil from being carried away by wind, water or any erosion agent. If this process occurs long enough, it can lead to desertification.
Deforestation
Forests are being cut down at a much larger scale than ever before to be used as fuel, to provide products we use in our daily life, or to simply create more space for agriculture to sustain the growing human population. Once the trees and other vegetation in an area are gone, there is nothing left to hold the soil in place. The soil then turns to dust and can be blown and washed away. In this way, the soil is degraded and the precious soil nutrients are lost, leaving the soil infertile and useless.
Outdated and unsustainable agriculture techniques
Improper irrigation methods in arid areas, such as canal irrigation, lead to a build-up of salt in the soil and make it difficult for crops and other plants to grow, hence increasing desertification. Similarly harmful is the cultivation of already deteriorated soils. Besides, while preparing the soil for sowing, natural vegetation that holds the soil in place is removed, making the land more vulnerable to degradation.
Monoculture is one of unsustainable agriculture techniques that leads to soil erosion and ultimately desertification of the land. Monoculture makes the soil very much exhausted. The soil structure, organic matter and fertility are all curtailed. Consequently, soil erosion sets on, which culminates to desertification.
In fact, any factor leading to soil erosion is also a causative factor for desertification.
Overpopulation
Our planet’s ecosystems sustain life only when balanced. Ecosystems can cope with incremental challenges and adapt but beyond a certain point they collapse. A rapid increase in human population demands higher amounts of natural resources and expands more and more over the landscape, leading to increased desertification.
Climate change
As humans continue to remove vegetation from landscapes, there is less vegetation remaining to add moisture to the soil that will evaporate into the air and form clouds that lead to rainfall. With significantly reduced rainfall, drought occurs and leads to a hotter and drier climate, and later causes desertification in the surrounding landscape.
Famine, poverty and political instability
While desertification certainly leads to these problems, they can also be a cause of desertification. This is because people on the brink of famine, extreme poverty or political instability in their country need to solve the crisis at the moment and do not think about sustainable cultivation strategies. Unfortunately, the outcome are poor land use practices such as keeping too many animals in a small pen and unsustainable short-term food production, which might destroy soils beyond repair, and put lives of people even more in danger.
Extent of desertification
Worldwide, dry lands occupy approximately 40–41% of Earth’s land area and are home to more than 2 billion people. It has been estimated that some 10–20% of dry lands are already degraded and the total area affected by desertification is between 6 and 12 million square kilometres. About 1–6% of the inhabitants of dry lands live in desertificated areas and a billion people are under threat from further desertification.
In Tanzania, the symptoms of desert encroachment are found almost everywhere in the country, although they are much more pronounced in the semi-dry and dry central, western and northern regions of Dodoma, Singida, Tabora, Kigoma, Arusha, Mara, Shinyanga and Mwanza.
These regions experience unusually long periods of drought, extensive deforestation, over-grazing, overstocking, below average rainfall of 600 to 900 millimetres, acute water shortage, and poor harvests that give rise to acute forms of malnutrition, especially among children and the aged.
Tanzania's National Environmental Management Council (NEMC) has repeatedly warned that desertification would cause an extremely negative socio-economic impact and grave ecological consequences, if immediate measures are not taken to check land degradation.
Losing an average of 400,000 hectares of land annually through deforestation, Tanzania has failed to protect and conserve its environment and achieve sustainable development.
The problem is made worse by the rising cost of kerosene and cooking gas which is used by many rural and poor people for cooking, heating and lighting. As many people cannot afford kerosene, they have resorted to cutting down trees for fuel (charcoal or firewood) which is relatively cheaper. The Sahel belt, a semi-desert region bordering the Sahara Desert, is expanding southwards.
As the rainfall is becoming less and unpredictable in many areas, the effects of climate change are becoming more glaring and desertification seems to be increasing.
Impacts (effects) of desertification
Desertification has many consequences to humans as well as the environment. Its impacts include the following:
Loss of soil fertility
As desertification occurs, the soil can be blown or washed away, and valuable soil nutrients are lost. Through the use of unsustainable irrigation techniques, salt can also build up in the soil, rendering the soil useless for growing crops or other plants. As the soil dries out, it hardens and it becomes difficult for water to penetrate below the soil’s surface. And what is left is a lifeless pile of dust instead of a life-giving medium.
Desertification reduces soil fertility, particularly base cation content, organic matter content, pore space, and water-retention capacity of the soil.
Vegetation is damaged or destroyed
Desertification reduces the ability of land to support plant life. Loose soil buries plants, or their roots become exposed and cannot fulfil their function. With plants dying, rainwater gets washed away instead of being drawn into the soil, which only scales up the problem as remaining plants do not have enough moisture to survive dry spells as they used to.
Additionally, if the land is used for grazing at this stage, it only results in a quicker loss of plant species and total degradation.
Soil erosion
The reduction in plant cover increases soil erosion due to increased runoff and direct exposure to wind. This results in the decrease of water storing capacity of soils. The process of desertification is worsened as the soil becomes increasingly arid, and there are no more plants to hold it in place and distribute nutrients. Soil erosion is the final step that closes the loop of continual soil deterioration that is impossible to revert.
Disasters
Desertification makes natural disasters worse. Events such as flooding, dust storms, and pollution, all become stronger in areas with heavily degraded soils. Without any plants stabilizing the soil and slowing down the runoff, rainwater easily accumulates and floods human settlements.
Apart from causing damage, flood water also picks up unwanted pollutants while making its progress through urban areas, and that’s how pollution spreads over vast areas.
Pollution of water sources
Vegetation plays an important role in cleaning our water. Plants function like natural filters, storing pollutants such as heavy metals from water in their own bodies. Barren soils lack this green filter, and therefore, more of these harmful substances enter our groundwater reservoirs.
Famine, poverty, and starvation
Desertification reduces vegetative productivity, leading to long-term declines in crop and livestock yields, plant standing biomass, and plant biodiversity. These changes reduce the ability of the land to support people, often sparking an exodus of rural people to urban areas.
Due to drought conditions and a loss of productive land, local people find themselves experiencing famine and poverty, as well as the starvation of themselves and their livestock.
Extinction of species
Species that once lived in a fertile and productive land may not survive in a newly desertified region. With a changing ecosystem, species must adapt to their new climate or migrate to a more favourable climate. Unfortunately, some of them also become extinct for their inability to cope with a sudden change of their environment.
Economic loss
Desertification forces the government to use its financial resources to rehabilitate and maintain the degraded land. This leads to economic loss as the money that could otherwise be spent on social services is directed towards rehabilitation of degraded land.
The above list of causes and effects of desertification is just a brief fraction of the whole scope of such an extensive problem taking place on our lands every day. Majority of those who are affected the most by this problem are as usual the world’s poorest nations, where people struggle daily with the direct impacts of climate turning against them, and deserts claim more of their already scarce soils. Therefore, it is important to realize how valuable soil conservation is and try to help protect our natural resources.

The Impact of Poverty on Environment

Explain the impact of poverty on environment
There is a strong relationship between poverty and the environment. Poverty is one of the main causes of forest and woodland degradation in developing countries, especially in Africa, and it is both a consequence and a cause of this degradation. A degraded environment produces less, so people become more vulnerable, for example, to waterborne and other diseases.
Poverty leads to deforestation through inappropriate use of wood and other resources for cooking, heating, housing and crafts. This is because people cannot afford cooking gas and kerosene. Some cut down trees to sell firewood or charcoal in order to get income to buy some essentials such as food and clothing. When people lack adequate financial and other resources, they are left with no choice but to turn to unsustainable use of natural forests and woodlands to meet their basic needs. It becomes a vicious circle.
Insufficient access to education and information make it difficult for poor people to manage available natural resources in a sustainable and sound manner, thus creating loss of livelihood opportunities and of biological diversity.
Air pollution generated by inappropriate production techniques used by poor people out of lack of better knowledge or lack of capital to invest in environmental friendly technologies, is also responsible for global warming and climate change.
Poverty often confines poor people in rural areas to marginal lands, thus contributing to an acceleration of erosion, increased ecological vulnerability, landslides, etc. Lack of resources in poor neighbourhoods leads to inadequate waste collection and waste management with subsequent health problems.
In rural areas, poverty leads to practising poor farming methods like shifting cultivation, monoculture, overcultivation and overgrazing. Bush fires set by honey collectors are also common. All of these render the soil bare and prone to erosion.
Poor people cannot afford to pay for cleaning and other community services. They also live in poor and unplanned settlements. As a result, the most severe environmental health problems are found predominantly in low-income homes and neighbourhoods. These include poor access to water, bad sanitation, contaminated food, uncollected waste, smoky kitchens and a range of insect vectors.
In urban areas the poor are engaged in urban agriculture, which has resulted in the destruction of green belts. Stream bank cultivation has contributed to siltation of the urban drainage systems.
Urban residents generally consume more renewable resources than rural people, placing heavy demands on the environment. Large concentrations of people also generate huge volumes of waste, resulting in pollution and health problems. Cholera and other water-borne diseases are spread through water often contaminated with untreated human waste and sewage.
Many poor women lack the resources necessary to engage in birth control. Therefore, it is common for poor women to continue having children well after they would have liked because of little or no access to resources and education. The more global population grows, the more weight is placed on the environment. Every human being consumes their share of resources from the environment, and with so many births originating from poor communities, the burdens placed on the environment grow heavier and heavier each day.

The Causes and Consequences of Global Climatic Change on Environment

Analyse causes and consequences of global climatic change on environment
Global climate change is the alteration in the characteristics and pattern of the world climates that is attributed to human activities which alter the composition of the global atmosphere. It should be noted that, to some extent, nature too can cause climate change, only that its rate is very slow compared to that associated with human activities.
Causes and consequences of global climate change
Energy from the sun drives the processes of heat and moisture transfer in the atmosphere. Any processes or activities that interfere with sun, and hence the solar energy, affects the climate of the Earth. Such interferences can be natural or man-caused. These factors, therefore, are considered to be the causes of global climate change.
Natural causes
The natural causes of global climate change include the following:
(a) Variation in solar radiation
The energy emitted by the sun only varies slightly. This change in solar radiation is related to the number of sunspots. Sunspots are darker areas on the sun’s surface. A sunspot develops where an intense magnetic field weakens the flow of gases that transport heat energy from the sun’s interior. Sunspots appear dark because their temperature is lower than the surrounding area.
Approximately every 11 years, the number of sunspots changes from a maximum number to a minimum number. The sun emits slightly more radiation during active periods of sunspots. While many sunspots may contribute to warmer global climate, fewer sunspots appear to be associated with a cooler global climate.
It is estimated that solar output could decrease at a rate of 1% per century. This alone could lead to a global drop in temperature of up to 1°C.
(b) Volcanic eruptions
Volcanic eruptions discharge carbon dioxide, but they may also emit aerosols, such as volcanic ash or dust, and sulphur dioxide. Aerosols are liquids and solids that float around in the air. They may also include soot, dust, salt crystals, bacteria, and viruses. Aerosols float in the atmosphere for long periods of time and are transported by wind around the planet. The aerosols scatter incoming solar radiation, causing a slight cooling effect.
This was the case in 1816 when Indonesia’s Mount Tambora erupted violently. A similar situation occurred when Mount Pinatubo (in Philippines) erupted in 1991 causing a significant dip in global temperatures in the following year or two.
(c) Variation in atmospheric carbon dioxide
The level of carbon dioxide concentration in the atmosphere dictates the global temperatures. The higher the concentration, the warmer is the temperatures. An increase in the population of organisms, including man and other animals, causes an increase in atmospheric carbon dioxide and hence global warming.
If temperatures were to drop to freezing point, a large volume of carbon dioxide would be trapped in the frozen water releasing less quantity in the atmosphere. This would lead to cooler conditions.
(d) Movement of crustal (tectonic) plates
As tectonic plates move over geological timescales, landmasses are carried along to different positions and latitudes. These changes affect global circulation patterns of air and ocean water and the climate of the continents.
Studies show that, since the industrial revolution, the Northern Hemisphere has warmed more than the Southern Hemisphere. This is because the Northern Hemisphere has a larger percentage of Earth’s landmass compared to ocean than the Southern Hemisphere.
Human causes
Humans are increasingly influencing the climate and the Earth's temperature by burning fossil fuels, cutting down rainforests and keeping livestock. This adds enormous amounts of greenhouse gases to those naturally occurring in the atmosphere, increasing the greenhouse effect and global warming.
The greenhouse effect causes the atmosphere to retain heat. When sunlight reaches the Earth’s surface, it can either be reflected back into space or absorbed by Earth. Once absorbed, the planet releases some of the energy back into the atmosphere as heat (also called infrared radiation). Greenhouse gases like water vapour (H2O), carbon dioxide (CO2), and methane (CH4) absorb energy, slowing or preventing the loss of heat to space. In this way, greenhouse gases act like a blanket, making the Earth warmer than it would otherwise be. This process is commonly known as the “greenhouse effect.”
Increase in atmospheric gases comes from human activities through emissions from burning coal, gas and oil in power plants and cars; cutting down and burning forests; tiny pollution particles (aerosols); black carbon pollution more commonly referred to as soot; and changes in land use. Forest and grassland fires and burning of litter, including plastics, also contribute to more gases in the atmosphere.
Deforestation reduces the population of plants which are the main consumers of carbon dioxide, hence leading to accumulation of excess of the gas in the atmosphere. Industrial and agricultural activities are also responsible for contributing gases such as methane, nitrous oxide, chlorine, fluorine and bromine to the atmosphere. Massive quantities of garbage also give off considerable quantities of these gases, especially methane.
Industrial chemicals called chlorofluorocarbons are used in aerosols, refrigeration, plastic industries and electronics. These are carelessly released into the atmosphere, thus causing damage to the protective ozone layer.
Consequences of global climate change on environment
Global climate change has already had observable effects on the environment. Glaciers have shrunk, ice on rivers and lakes is breaking up earlier, plant and animal ranges have shifted and trees are flowering sooner.
Effects that scientists had predicted in the past would result from global climate change are now occurring: loss of sea ice, accelerated sea level rise and longer, more intense heat waves.
Humans and wild animals face new challenges for survival because of climate change. More frequent and intense drought, storms, heat waves, rising sea levels, melting glaciers and warming oceans can directly harm animals, destroy the places they live, and wreak havoc on people’s livelihoods and communities. The effects of climate change on the environment include the following:
(a) Increased precipitation
Precipitation (rain and snowfall) has increased across the globe, on average. Global warming leads to a rise in temperature and hence increased evaporation. The ultimate outcome is more than average rainfall in some regions, causing flooding and making the wetlands wetter than before.
(b) Increased atmospheric temperature
As noted above, the increase in temperature would make some regions hotter than before. This extreme temperature would make some regions turn semi-arid because of increased evaporation. Consequently, water resources could dry up at a faster rate. The Earth's average temperature has increased about 1°C during the 20th century.
(c) Rise in sea level
Ice is melting worldwide, especially at the Earth’s poles. This includes mountain glaciers, ice sheets covering West Antarctica and Greenland, and Arctic sea ice. The melting ice and glaciers would cause an increase in sea level.
Likewise, the ice cap on Mount Kilimanjaro and glaciers on Mount Kenya are shrinking because they are melting more than before.
(d) Change in world’s climate patterns
Climate change resulting from increasing temperatures will likely include changes in wind patterns, annual precipitation and seasonal temperatures variations.
Climatic patterns in most parts of the world have already changed. Rains fall when least expected and at irregular intervals. This has greatly affected the timing of planting and harvesting activities. Sometimes the rains fall so heavily to cause floods, or too little leading to drought.
Most of the arable land that once used to be productive is slowly turning arid. With time, farmers will run short of the land for cultivation, a fact which will result in famine.
(e) Ocean acidification
As levels of atmospheric carbon dioxide increase, the oceans absorb some of it. This increases the acidity of seawater.
Because acids dissolve calcium carbonate, seawater that's more acidic has a drastic effect on organisms with shells made of calcium carbonate, such as corals, mollusks, shellfish and plankton. The acid water is likely to dissolve the carbonaceous shells, thus endangering the lives of these aquatic creatures. Change in ocean acidity will also affect fish and other aquatic animals and plants.
(f) Disruption of natural ecosystems
Change in conditions of a natural ecosystem due to climate change is likely to make some species of organisms extinct while others might adapt to the new conditions or move to suitable environments. For example, some butterflies, foxes, and alpine plants have moved farther north or to higher, cooler areas. In general, many species have expanded their ranges poleward in latitude and upward in elevation.
There has been some evidence on changes in distribution of ecosystems, e.g. desert ecosystems have expanded, and tree lines in mountain systems have changed. Desertification could increase due to increased soil erosion. Grasslands might expand while forest areas would shrink.
Changes in the composition of ecosystems have also been observed (e.g. increased climbing plants in tropical forest). Such changes may affect ecosystem functions and services.
However, changes in biodiversity and ecosystem services due to climate change are not all negative, with some species either thriving or adapting.
(g) More frequent and intense heat waves
Dangerously hot weather is already occurring more frequently than it did 60 years ago, and scientists expect heat waves to become more frequent and severe as global warming intensifies. This increase in heat waves creates serious health risks, and can lead to heat exhaustion, heat stroke, and aggravate existing medical conditions.
(h) Loss of habitats and biodiversity
Many species of plants and animals are already moving their range northward or to higher altitudes as a result of warming temperatures.
Additionally, migratory birds and insects are now arriving in their summer feeding and nesting grounds several days or weeks earlier than they did in the 20th century.
Warmer seasons will lead to an increase in pests and disease-causing pathogens that were once confined to tropical and subtropical areas, killing off plant and animal species that formerly were protected from disease. For example, spruce bark beetles have boomed in Alaska thanks to 20 years of warm summers. The insects have chewed up 4 million acres of spruce trees.
(i) Famine and disease threat
Agricultural systems will likely be highly affected. Though growing seasons in some areas will expand, the combined impacts of drought, severe weather, lack of snowmelt, greater number and diversity of pests, lower groundwater tables and a loss of arable land could cause severe crop failures and livestock shortages worldwide.
This loss of food security might, in turn, create havoc in international food markets and could spark famines, food riots, political instability and civil unrest worldwide.
The effect of global warming on human health is also expected to be serious. An increase in mosquito-borne diseases like malaria and dengue fever, as well as a rise in cases of chronic conditions like asthma, are already occurring, most likely as a direct result of global warming.
(j) Increased ultraviolet radiation
Increased ultraviolet radiation from the sun above normal rates is caused by depletion of the ozone layer. This radiation is harmful to organisms. Humans, animals and plants are affected in the following ways:
  1. Increased sunburn.
  2. Snow blindness.
  3. Increased eye diseases such as cataracts.
  4. Increased incidences of skin cancer, including melanoma (a cancer that develops in melanocytes, the pigment cells present in the skin).
  5. Impaired ability of the body’s immune system.
  6. Rapid aging and skin wrinkling.
  7. Lower crop and timber yields.
  8. Lower fish population.

Environmental Conservation

Define Environmental Conservation
Environmental conservation is the protection, preservation, management, or restoration of natural environments and the ecological communities that inhabit them. It entails the protection and preservation of natural resources from destruction, wastage or loss. Thus, conservation of the environment involves the conservation of the natural resources. The natural resources include soil, minerals, water, air, animals and plants.
Various Ways of Conserving the Environment
Analyse various ways of conserving the environment
There are numerous ways in which environmental protection and conservation can be achieved. The following are some of the measures that can be taken to conserve the environment:
Recycling and re-use
Emphasis is being put on recycling by buying reusable and biodegradable products as much as possible. Whether it is glass or paper, plastic or metal, all these materials can be re-used. Remember it takes a million years for glass to decompose.
Plastic bags are not biodegradable either and they are used in huge quantities every year. Reusable containers and bags would be a healthy, environment-protective alternative. Therefore, re-use every reusable material rather than damping it onto the environment.
Afforestation and reforestation
Reforestation refers to establishment of a forest on land that had recent tree cover, whereas afforestation refers to establishment of a forest on a land that has been without a forest for much longer. Trees absorb excess carbon dioxide from the air, thus helping to curb greenhouse effect and global warming. Trees also help in attracting rainfall, controlling soil erosion, and modifying the climate.
Rehabilitation of derelict land
People engaged in quarrying and mining are encouraged to rehabilitate the land on which the activities have taken place. The simplest method of reclaiming a derelict land involves simply filling the undulating land with large amounts of heavy rock and/or cement until the desired level is attained.
Draining of submerged wetlands is often meant to reclaim land for agricultural use. Deep cement mixing is used typically in situations where the material displaced by either dredging or draining may be contaminated and hence needs to be contained.
Various techniques are employed in land reclamation. The method chosen for reclaiming the land depends on the state of the land in question. The methods often employed include irrigation, afforestation and reforestation, drainage, landfill, flushing or acidification.
Reducing the use of agrochemicals
Farmers should be advised and encouraged to avoid dependency on agricultural chemicals (fertilizers, herbicides, pesticides, etc). All of these chemicals poison the soil, and affect animals and crops a great deal. Instead, farmers should use organic manures and chemicals to fertilize their farm fields and to control pests and diseases. Organic manures and pesticides do not pollute the land or affect crops and animals.
Setting up organizations and institutions
Many organizations have been set up for the purpose of conserving the environment. These organizations include international organizations, government ministries and agencies and non-government organizations.
Examples of government ministries and agencies include the Ministry of Natural Resource and Tourism and the National Environment Management Council (NEMC) respectively. An example of an international agencies concerned with environmental conservation is the United Nations Environment Programme (UNEP).
Legislation
The laws that govern environmental conservation are being made and enacted. The laws aim at curbing environmental destruction by punishing or fining those individuals who destroy or litter our environment.
Education
People are being educated about the importance of conserving the environment for their benefits and future generations. Environment education is being continually offered in schools, colleges, universities and other organizations. Academic institutions now offer courses such as environmental studies, environmental management, and environmental engineering that teach the history and methods of environmental protection.
Research
Research is being carried out on the best ways to protect and conserve the natural resources. Some of the areas of research include the following:
  • alternative sources of energy;- methods of preventing and controlling pollution;
  • sustainable use of natural resources;
  • recycling and reuse of material; and
  • environmental impact assessment
International agreement
International organizations such as the United Nations (UN) and regional blocks such as the European Union (EU) have drafted agreements which provide guidelines on the conservation of the environment. Member nations commit themselves by signing and implementing these agreements. Most of the agreements are legally binding for countries that have formally ratified them. Such agreements include the Kyoto Protocol which was agreed upon in Kyoto, Japan on December 11, 1997.
In 2005, several countries of the world signed the Kyoto Accord whereby they agreed to reduce the amount of greenhouse gases they emit. More than 80 countries, including Tanzania, signed the accord. Most countries have now ratified the Kyoto Protocol. Fun enough, USA, the major world producer of greenhouses gases, has never signed the protocol!
Personal involvement
It is crucial that everyone gets involved in the conservation of the environment at individual level. Each citizen should feel obliged to take part in conserving the environment. We cannot let the task be done by the government, agencies and the international organizations alone. This is because we are all involved in environmental destruction, and the effect of this destruction affects all of us.
The following are some of the ways in which you can participate in environmental conservation:
  1. Plant more trees at home and farm fields, school and village forest. Do not cut down tress indiscrimately because doing so leaves the soil bare and vulnerable to soil erosion.
  2. Always dump litter in areas designated for waste disposal and in litter bins. Do not just throw dirt anywhere and carelessly.
  3. Do not start fires near forests. Farmers should not prepare their farm fields by burning the vegetation because the fire can spread and destroy trees and nearby forests. Fire also kills important soil micro-organisms, thus curtailing soil fertility and productivity.
  4. Do not harm domestic and wild animals by any means. Be kind to animals and treat them humbly.
  5. Convey environmental conservation education to all people. Let them know the importance of conserving and living in a clean environment.
  6. Participate in environmental conservation programmes and tasks. These include World environment Day (June 5, every year) and clear-up exercises in the local area or town.
Environmental Conservation and Management at School Level
Practice environmental conservation and management at school level
This part is practically based on organizing students in groups to practice various ways of conserving the environment such as planting trees or flowers, and cleaning environment around the school compound.
The responsibility of protecting our dear planet Earth should start from the domestic to international level. Schools have a very unique role in environmental conservation. Environmental management education should be incorporated in national curriculum. Also students should be nurtured to preserve the environmentfrom the primary school level.
 ⏩⏪ INTRODUCTION TO RESEARCH 

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