Unit-4.pdf global enviroment issues and slow

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UNIT 4 GLOBALENVIRONMENTAL
ISSUES
Structure
4.0 Introduction
4.1 Objectives
4.2 Environmental Degradation
4.2.1 Causes of Environmental Degradation
4.2.2 Effects of Environmental Degradation
4.3 Climate Change
4.3.1 Causes of Climate Change
4.4 Green House Effect and Global Warming
4.5 Acid Rain
4.5.1 Effects of Acid Rain
4.6 Ozone Layer and its Depletion
4.7 Other Issues
4.8 Case Studies
4.9 Let Us Sum Up
4.10 Key Words
4.11 References and Suggested Further Readings
4.0 INTRODUCTION
Environment is all that surrounds us. It consists of biotic as well as abiotic
components. You have studied about these components in the previous units.
Man has been utilizing the services and products of environment for his own
good self. In the process, the nature and its components have been altered and
their character has been changed. In view of this, the healthy survival of human
beings and other organisms has become very difficult on this planet.
Environmental problems do not believe in boundaries and an issue at one place
also travels to the nearby place and manifests in some form or another. There
are local as well as global issues which are demanding immediate attention. In
this unit, you will learn about the issues which are equally affecting the world
in some form or the other. The extent of impact may vary but counties across
the world are pondering over the solutions to these issues.
4.0 OBJECTIVES
After reading this unit, you will be able to:
l describe the factors causing environmental degradation;
l explain the effects of climate change;

50
Environment and Ecology l explain the meaning of green house effect;
l define acid rain and mention the forms of acid rain; and
l explain the effects of ozone depletion.
4.2 ENVIRONMENTAL DEGRADATION
Environmental degradation is the deterioration in the qualityof the environment.
It is apparent in more than a few forms such as depletion of natural resources,
destruction of ecosystems, habitat damage, the extinction of wildlife and
environmental pollution. Despite the fact that the state of the environment has
always been changing since life evolved on this planet, the magnitude of change
and severity of impact is today like never before. The degree and the level of
environmental degradation depend upon the rate, the resilience of living
organisms and the intervening factors. The present condition reveals that the
damage has been to such an extent that it is believed that some environments
may never recover. We have lost our pristine environment and we will never
be able to recover it.
There are a number of causes of environmental degradation. You must have
read at various places that humans are mainly responsible for this damage.
Therefore, humans must recognize the degree to which they depend on earth’s
resources and what are limits of the usage of these resources. It is necessary to
devise means for the sustainable utilization of precious natural resources. In
this sense, environmental responsibility and stewardship constitute an integral
part of effective resource management practices. In order to avoid more harm,
researchers and scientists must consider the long-standing impact of
development on the environment and must come out with suitable measures
to minimise future environmental degradation.
4.2.1 Causes of Environmental Degradation
Let us now understand the causes behind environmental degradation. Various
natural as well as anthropogenic factors are responsible for altering the character
of the surroundings. Let us learn more about them.
l Natural Causes
Along with anthropogenic activities, natural causes also create instability
in environment. Events such as earthquakes, floods, wildfires and
landslides cause damage to life and property along with disrupting the
landscape of that region. Alteration of the habitat makes survival of the
plants animal communities difficult. It is because of the fact that the climate
of Earth has also been changing over time.
l Man –made causes
As compared to the natural causes, man-made causes are known to cause
environmental degradation at a much wider scale. Some of the important
man made causes of environmental degradation are deforestation,
environmental pollution, improper land use planning and development,
overexploitation of natural resources, improper agricultural practices, poor
quality of water resources, wetlands and aquatic life and enormous waste
generation. During 1960 to 1999, the world population increased manifold
because at this time we had improved medical facilities, vaccinations,
better nourishment and the deadly diseases were controlled. The death

51
rate drastically declined during this period. During the same period, the
environmental problems also grew and the world’s attention shifted to
the concerns of the environment. The landmark environmental events took
place in the same period. Since then the environmental problems have
become more intense and more complicated. Human beings have disturbed
the ecology and natural processes in the name of development. Unless
some stringent measures are taken, it will be very difficult to restore the
nature of forests and oceans and other ecosystems.
4.2.2 Effects of Environmental Degradation
Environmental degradation hinders with the renewal capacity of the renewable
natural resources and thus checks their availability. It also contributes to the
decrease in quality of the land, water, genetic resources, medicinal plants and
food crops. Below are some of the chief effects of environmental degradation.
You will learn more about the effects of environmental degradation in detail in
subsequent units of this course.
l Atmospheric Changes
Environmental degradation disturbs the natural biogeochemical cycles
and other processes of nature. Reckless deforestation and mining activities
destroy the natural land cover and alter the chemical composition of the
atmosphere. It causes the manifestation of the already existing problems
of global warming and release of green house gases. Along with this, the
intensity and frequency of natural disasters also increases. The overall
result is the shift in the precipitation patterns and likewise changes in the
atmosphere.
l Environmental Pollution
Environmental degradation is responsible for the addition of harmful and
unwanted chemicals into the environment. Rapid industrialisation and
unplanned development activities have done more harm than good.
Agriculture is slowly poisoning our fields and the fruits and the vegetables
are contaminated with pesticides.Air is also getting polluted and our water
bodies are full of filth of waste and harmful chemicals. There are heaps of
solid and municipal wastes in secluded places which is responsible for
land pollution. In a nut shell, environmental pollution has crossed all limits
and it is one of the most visible forms of environmental degradation.
l Decline in Biodiversity
Degradation of the environment has lead to the destruction of forests and
natural ecosystems. The number of threatened species continues to increase
worldwide and many have also become extinct. It is because of the
acidification of the water bodies, deforestation, and the deliberate
destruction of natural habitat of living organisms.
l Impact on Human Health
Human beings do not remain impervious from what is happening in the
surroundings. Human health depends on environmental factors to a large
extent apart from genetic and behavioural factors. Urbanization and
modernisation have changed the lifestyle of people in rural as well as
urban areas. We are breathing impure air, drinking contaminated water
and eating stuff that is laden with pesticides. To make matter worse,
electronic gadgets and radiations have become part and parcel of our lives.
Global Environmental Issues

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Environment and Ecology In this way, human beings are paying the cost of development in the form
of deteriorating health and qualitylife. Degradation in water qualitycauses
water borne diseases to the children and the poor across the globe.
Similarly toxic gases and harmful chemicals are released from factories
and automobiles leading to poor air quality. Due to this, respiratory and
cardiovascular diseases are affecting a large population in developed as
well as developing countries. Growing number of cancer patients,
increasing risks of obesityand lifestyle related diseases and poor immunity
among children are all the consequence of environmental degradation in
one form or the other.
l Poverty
In the developing countries, poverty is linked to lack of natural resources
and basic needs that are needed to survive. Poverty is the result of number
of factors like unemployment, lack of adequate food and improper means
of living. Most vulnerable situations arise because of water shortages,
climate change, and poor crop yields in developing countries. All this is
linked to environmental degradation in some form or the other.
Apart from the effects mentioned above, it can be asserted that
environmental degradation also indirectly leads to a number of socio
economic consequences.
Check Your Progress 1
Notes: (a) Write your answers in bout 50 words.
(b) Check your progress with possible answers given at the end of
the unit.
1. Explain the causes of environmental degradation.
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2. How human health is affected by environmental degradation?
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4.3 CLIMATE CHANGE
Climate is usually defined as the “average weather” at any place. It includes
patterns of temperature, precipitation, humidity and wind. These patterns play
a fundamental role in shaping natural ecosystems, and the human economies
and populations that depend on them.
The Earth’s climate has changed throughout history. Most of these climate
changes are attributed to very small variations in Earth’s orbit that change the
amount of solar energy our planet receives. However, the current warming
trend is of particular significance because most of it is very likely human-

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induced and proceeding at a rate that is unprecedented in the past 1,300 years.
With the changing climate like never before, the past is no longer the reliable
predictor of the future. The change in climate is progressing faster than any
seen in the last 2,000 years and this forms a reason to study climate and the
changing climate. Rising global temperatures are expected to raise sea levels,
and change precipitation and other local climate conditions. Changing regional
climate could alter forests, crop yields, and water supplies. It can also affect
human health, animals, and many types of ecosystems.
4.3.1 Causes of Climate Change
It is verydifficult to say what actuallycauses climate to change at an accelerated
rate. Broadly speaking, the causes of climate change fall in two categories:
Natural and Man-made causes.
l Natural causes
There are a number of natural factors responsible for climate change. Some
of the more prominent ones are continental drift, volcanoes, ocean currents,
the earth’s tilt, and comets and meteorites.
l Continental drift
Continental drift also had an impact on the climate because it changed the
physical features of the landmass, their position and the position of water
bodies. The separation of the landmasses changed the flow of ocean
currents and winds, which affected the climate. This drift of the continents
continues even today. The Himalayan range is rising by about 1 mm every
year because the Indian land mass is moving towards theAsian land mass.
l Volcanoes:
When a volcano erupts it throws out large volumes of sulphur dioxide
(SO2
), water vapour, dust, and ash into the atmosphere. Although the
volcanic activity may last only a few days, yet the large volumes of gases
and ash can influence climatic patterns for years.
l The earth’s tilt
The earth makes one full orbit around the sun each year. It is tilted at an
angle of 23.5° to the perpendicular plane of its orbital path. If there was
no tilt we would not have experienced seasons. Changes in the tilt of the
earth can affect the severity of the seasons - more tilt means warmer
summers and colder winters; less tilt means cooler summers and milder
winters.
l Ocean currents
Ocean currents have been known to change direction or slow down. Much
of the heat that escapes from the oceans is in the form of water vapour, the
most abundant greenhouse gas on Earth. Yet, water vapour also contributes
to the formation of clouds, which shade the surface and have a net cooling
effect.
l Man Made Causes
Excess burning of fossil fuel, change in land use patterns are some of the
leading causes of climate change.. Since Industrial Revolution, human
activities have significantly altered the climate at given place. It is because
of the influence of human activities on climate change we use the term
‘anthropogenic’ or ‘human induced’ climate change.

54
Environment and Ecology
4.4 GREEN HOUSE EFFECTAND GLOBAL
WARMING
The greenhouse effect is the phenomenon in which the atmosphere of a planet
traps radiation emitted by sun. Green house effect is caused by gases such as
carbon dioxide, water vapour, and methane that allow incoming sunlight to
pass through but does not allow heat to radiate back from the Earth’s surface.
In the absence of green house effect, the global average temperature would
have been -18°C (0°F) instead of 15°C (59°F) which is today. Since the
industrial revolution got into full swing in the 19th centurywe have been burning
ever increasing amounts of fossil fuels (coal, oil, gasoline, natural gas) in electric
generating plants, manufacturing plants, trains, automobiles, airplanes, etc.
The overall result is the warming of the earth’s surface which is termed as
Global Warming.
Global warming is causing intense consequences on the climate of the earth
and life and livelihood of people. Rising temperature leads to melting of glaciers
and rising sea level through addition of melt water to the oceans. It also causes
thermal expansion of water in oceans which in turn is also responsible for sea
level rise. Sea level rise leads to increasing coastal erosion, flooding, and
property damage during coastal storms. It is predicted that warmer sea surface
temperatures will result in more and stronger tropical storms like hurricanes
and typhoons increasing the loss of life and damage to infrastructure. While
higher temperatures will produce more rainfall across the globe, the regional
rainfall patterns will likely change. Some areas will get more, some areas will
get less. The timing of wet and dry periods may change. Centuries old farming
practices will have to change. Some areas may go from being marginal to
becoming a breadbasket region, while other regions may go from major
agricultural production to marginal. Natural ecosystems will be hard pressed
to keep up with the changing climate because the rate of change will be faster
than typical long-term natural climate change. Many species, especially plant
species, will not be able to migrate to cooler areas fast enough to keep up with
the warming of their habitats. Arctic species will have no place to go and may
not be able to adapt to the new conditions. Harsh summers will cause death
and miseries to a large population. Higher heat and expansion of tropical areas
may lead to increased prevalence of tropical diseases such as malaria.
the unit.
1) How global warming will lead to ecosystem imbalance and species loss
in the long run?
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2) What is the greenhouse effect?
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4.5 ACID RAIN
Acid rain refers to the wet or dry deposition of the excess amount of nitric and
sulphuric acid. In simple words, it means rain that is acidic in nature because
of the presence of certain pollutants emitted through vehicular and industrial
pollution. The term was introduced by a Scottish chemist, RobertAngus Smith,
in 1852. Volcanic eruptions, burning of fossil fuels, emissions from factories
and automobiles are few other causes of acid rain. Normal rain water is also
slightly acidic having a pH range of 5.3-6.0. When the pH level of rain water
falls below this range, it becomes acid rain.
At present, large amount of acid deposition is observed in Canada, United
States and most of Europe.
Forms of Acid Rain
Acid deposition may occur in two forms: wet and dry.
l Wet Deposition: When the acids fall to the ground in the form of rain,
sleet, fog, snow or mist it is called wet deposition of acid rain.
l Dry Deposition: When the acidic pollutants enter into dust or smoke and
fall to the earth as dry particles it is called dry deposition. These pollutants
also deposit houses, trees and buildings.
4.5.1 Effects of Acid Rain
Acid rain has significant effects on forests, soil, aquatic life, human beings
and materials.
l Effect on Forests
Acid rain is known to cause severe damage to the forests in Germany,
Poland and Switzerland. It makes trees susceptible to diseases, destroys
their leaves and causes stunted growth of the plants.
l Effect on Aquatic Environment
Acid rain flows into streams, rivers and lakes and over a period of time,
acids get accumulated in the water. In such situations, the conditions
become unsuitable for the survival of aquatic flora and fauna. It leads to
reduced aquatic biodiversity.
l Effect on Soil
The physico chemical and biological properties of the soil are damaged
due to excess acids in rain water.An optimum pH level is required for the
activity of microbes in the soil.

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Environment and Ecology l Effect on Architecture and Buildings
Acid rain affects the infrastructure and buildings at any given place. . It
causes weathering of buildings, corrosion of metals, and peeling of paints
on surfaces. Buildings made of marble and limestone is severely affected
due to the reactivity calcium compounds and acids. The effects are clearly
visible on statues, historic monuments, and buildings. Acid rain also
corrodes metals like copper, and iron.
l Effect on Human Health
Human health is not directly affected by acid rain. However, gaseous
particulates in the air like nitrogen oxides and sulphur dioxide cause
respiratory disorders and heart problems.
4.6 OZONE LAYER AND ITS DEPLETION
Ozone is an allotrope of oxygen. When present in troposphere, it acts as a
pollutant but when present in stratosphere ozone layer protects life on earth by
absorbing harmful ultra violet radiations. Due to the release of chlorofluro
carbons (CFCs), the ozone is getting depleted and this thinning of the ozone
layer is commonly termed as Ozone depletion. The primary source of CFCs is
refrigerators, by product of industrial processes, aerosols, fire extinguishers,
etc. CFCs interfere with the ozone formation process in the stratosphere and
ozone depletion occurs when the natural balance between the production and
destruction of ozone in the stratosphere is tipped in favour of destruction. You
will learn more about the mechanism of ozone layer depletion in Unit ....of
Block.
The ozone layer is important because it absorbs ultraviolet (UV) radiation
from the sun, preventing most of it from reaching the earth’s surface. The
depletion of ozone layer allows entering of UV rays from sun into the earth’s
atmosphere which is associated with a number of health related problems in
human beings. Following are some of the effects of ozone layer depletion:
Skin Cancer: Exposure to UV rays leads to increased risk for developing of
several types of skin cancers.
Eye Damage: UV rays are harmful to our eyes. Direct exposure to UV rays
can lead to cataract, or snow blindness.
Damage to Immune system: Increased exposure to UV rays can lead to
weakening of the immune system.
Aging of skin: Exposure to UV rays accelerates the ageing process of the
skin.
Along with these, difficulty in breathing, chest pain, and throat irritation,
etc. are some of the common ailments caused due to ozone layer depletion.
Increased concentration of UV rays affects other forms of life as well. It
adversely affects the fauna which plays a vital role in the food chain and
carbon cycle in aquatic ecosystems. It also impairs the flowering in some
plant species and alters the physiological and developmental processes of
the plants.

57
It is necessary for the countries world over to take some stringent measures to
protect the ozone layer from getting depleted. More and more International
agreements such as Montreal protocol between countries are necessary to bring
down the release of chloro fluro carbons. At individual level everyone can
contribute towards reducing ozone layer depletion. The most important thing
that we can do is spreading awareness regarding these issues. Our individual
efforts will go a long way in protecting the earth and keeping it liveable for
future generations.
4.7 OTHER ISSUES
Apart from those mentioned above, the world is confronting quite a lot of
other issues of global concern. Let us get a brief idea about some other
environmental issues of global importance.
l Environmental Pollution
Environmental pollution has become a serious problem the world over which
is threatening the existence of not only man-kind but of other living organisms
as well. It is one of the greatest problems that we are facing today. Environmental
pollution consists of four basic types of pollution, namely, air, water, soil, and
noise. Harmful gases in air, contaminants in water, plastics and toxic chemicals
in soil, etc are the clear indicators that the environmental pollution has reached
the tipping point. Industries, vehicular pollution, fossil fuel burning are
responsible for the addition of sulphur dioxide, carbon di oxide and green
house gases (as you have studied in the previous sections) into the atmosphere.
Similarly agricultural runoff and industrial effluents are polluting the rivers
and lakes. Ganga, Yamuna and all, the main rivers of India are polluted and the
water is unfit for use. It can also be said that an arrayof environmental problems
like biodiversity decline and water shortages are occurring because of
environmental pollution. We have sacrificed the pure water and air for the
development process. Human beings particularly the poor, elderlyand children
have become susceptible to various diseases like asthma, cancer, infections
and the like. It is necessary on the part of the government to take measures on
urgent basis to stop the addition of contaminants in nature. Along with this, at
an individual level, every citizen must contribute to save planet from getting
polluted.
l Loss of Biodiversity
Biodiversity refers to the diversity in the various life forms present on the
Earth. It is the link between all organisms on earth, binding each into an
interdependent ecosystem, in which all species have their role. In other words
it can also be called as the web of life. The varied flora and fauna helps to
restore the ecological balance and provides various environmental services
apart from providing direct benefits such as food, medicines and raw materials.
The main cause of the loss of biodiversity can be attributed to the manipulation
of world’s ecosystems by human beings. They have transformed 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 place to another. Due to environmental pollution,
habitat fragmentation and land degradation, the plant and the animal species
are constantly under threat. We are losing a number of species every year

58
Environment and Ecology because they are not able to cope up with the changing climate and fragmented
habitats. The loss of biodiversity leads to disruption of ecological balance and
deprives us of the various direct and indirect benefits that they provide.
Biodiversity conservation is taken up by several international bodies such as
IUCN, WWF, etc. These conservation bodies have alreadysent warning signals
for countries to take necessary action to protect the flora and fauna.
l Desertification
Desertification is a process of land-degradation by which a region becomes
progressively drier and drier eventually becoming desert. Much of the
desertification across the world is caused byhuman activities. Poor agricultural
practices, unplanned deforestation, soil erosion, mining, urbanization, faulty
irrigation practices, etc. are some of the underlying factors of the process. It is
estimated that around 25 % of India’s land is undergoing desertification. The
situation will further heighten because of the impact of climate change,
particularly in dry lands. Due to this, desertification is significantly emerging
out as a global ecological and environmental problem. It has been found that
in the past several civilizations such as Harappa have collapsed on account of
desertification. Loss of productivity, famines, loss of natural vegetation is some
of the other effects of desertification.
l Depletion of Natural Resources
With 7 billion people living on the planet and their increasing demands, the
pressure on natural resources like water, land, forests, etc is bound to increase.
Since earlier times, human beings have utilized the nature’s resources and
services for getting food, shelter and clothing and making life comfortable.
However, when greed takes over need, the over exploitation of natural resources
starts becoming an issue of concern. Today we are utilizing more resources
than their capacity to replenish. Coal, minerals, oil, forests etc, are already
dwindling and losing their quality. In view of this, conservation of natural
resources is becoming a subject of paramount importance. Resource depletion
is of more concern in farming, fishing, mining, water usage, and consumption
of fossil fuels. Due to this, there is already scarcity of water and land. Most of
the pollution problems are growing because of natural resource depletion. When
resources are scarce people tend to use cheaper and lowqualityfuels for meeting
their daily needs. Hence, natural resource management is essential for the
sustainability of our development processes. Measures should be taken to
conserve water, and energy. Extensive programmes for afforestation and
protection of biodiversity must be undertaken to conserve the resources. Green
technologyand ecofriendly know-how must be utilized extensivelyto conserve
the natural resources.
l Waste Generation and Accumulation
Millions of tons of waste products are generated every day in big cities owing
to rapid industrialisation and urbanization. In India, 960 million tonnes of solid
wastes are generated annually as by-products during industrial, mining,
municipal, agricultural and other commercial and non commercial activities.
The sources and kinds of these wastes may vary but one thing is common that
theyare a menace to the environment as well as society. You must have noticed
heaps of wastes lying untreated at various places. There is a great accumulation
of wastes which needs proper disposal method. Proper waste disposal is

59
necessary so that wastes may get converted into resources. Organic wastes
must be treated to form manure which can be used in vegetable gardens.
Similarly recyclable waste must be recycled. If suitable measures are not
undertaken the earth will become a dustbin containing plastics, papers,
chemicals, glass and so on.At present most of the Indian cities dump the entire
quantum of their municipal solid waste into unscientific dump sites, whilst
only partially separating waste recyclable and non recyclable waste. The need
of the hour is to curtail our waste generation by recycling to full potential and
scientifically managing the remaining waste stream.
4.8 CASE STUDIES
There are several cases across the world to support the evidence that
environmental degradation is occurring at a faster rate than ever before. These
cases will help you to understand the causes of environmental degradation in a
precise way and you will be able to think independently and devise solutions
for the current problems. Let us read some case studies below:
l Minamata Disease
Minamata disease is a neurological syndrome that results from industrial
pollution and water pollution. Symptoms include ataxia, numbness in the hands
and feet, general muscle weakness, narrowing of the field of vision and damage
to hearing and speech. Minamata disease was first discovered in Minamata
City in Kumamoto prefecture, Japan in 1956. It was caused by the release of
methyl mercury in the industrial wastewater from the Chisso Corporation’s
chemical factory, which continued from 1932 to 1968. This highly toxic
chemical bioaccumulated in shellfish and fish in Minamata Bayand the Shiranui
Sea, which when eaten by the local populace resulted in mercury poisoning.
While cat, dog, pig and human deaths continued over more than 30 years.
l Sahel: The Expanding Desert
In the Sahel Desert, desertification is becoming a huge problem. Around the
1950s, people settled into the Sahel region, in areas where there was water.
This resulted in overgrazing, which is one of the greatest causes of
desertification. Eventually, the perennial shrubs were destroyed because of
grazing, and they were replaced by annuals. Then, the annuals were grazed out
which left bare soil. A lot of the topsoil was washed away, and all that was left
were rocks. Silt turned hard when it was hit by rain. Therefore, plants were not
able to grow there because roots could not penetrate this hard layer. Now this
region has turned to desert and it continues to expand. (Desertification, The
Sahel, 2004) Records show that rainfall in Sahel has decreased and sands have
shifted about sixty miles south into the area. Sahel is expanding due to lack of
vegetation in the area. (Sahel, 2005)Another reason desertification is occurring
in the Sahel region is because people are using the slashing and burning method
to clear land. This degrades the quality of soil just like overgrazing.
(Desertification-a Threat to the Sahel, 2000).
l Pesticide Poisoning in Punjab
The southern districts of Punjab- Mansa, Sangrur, Bhatinda, Faridkot, Moga,
Muktsar, Ferozepur and Sangrur, which together make up the Malwa region,
constitute the record number of cancer patients in the country. It is in this

60
Environment and Ecology Malwa region that scores of farmers and their families are coming to grips
with cancer and numerous health problems due to the lush fields hiding a
scary tale. Malwa, which is also Punjab’s cotton belt, requires the use of a
startling amount of pesticides. Reportedly, farmers in this region use 15 different
pesticide sprays and the unregulated and excessive use of chemical fertilizers
and pesticides have resulted in farmers and their families living in a cesspool
of toxicity. It is for this reason that excessive pesticide use has been cited as a
reason for the high incidence of cancer in Punjab. The researchers have found
that contaminated water from rapid industrialization and excessive use of
chemical fertilizers and pesticides for high-yielding crops are contributing to
increasing the number of cancer patients. These patients travel through the
“cancer train” to Bikaner to get themselves treated. The 12-coach train train is
named so because every day it carries not less than 100 patients who attribute
the cause of cancer in Punjab to pesticide use and growing pollution.
the unit.
1) What are the harmful effects of ultraviolet radiations?
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2) How does acid rain affect aquatic life?
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4.9 LET US SUM UP
The environment all over the planet is witnessing drastic changes in its
composition and processes. This change in the settings of the environment is
commonly termed as environmental degradation Environmental degradation
is evident in the form of environmental pollution, decreasing the availability
of natural resources, loss of biodiversity and generation of waste. The
environmental problems are not region specific as they do not have boundaries.
Pesticides sprayed in field cause air pollution in the nearby areas. Thus issues
of environment have become global in nature. Climate change, global warming,
ozone depletion and acid rain are the issues of global importance in terms of
magnitude and extent of impact. It is necessary to take immediate steps to
control emissions and release of chemicals in land, air and water to prevent
environmental degradation.

61
4.10 KEY WORDS
Global warming : Increase in the average temperature of the Earth due to
the release of greenhouse gases.
Acid Rain : Acid rain is any form of precipitation that is highlyacidic
Stratosphere : The stratosphere is a layer of Earth’s atmosphere. It is
the second layer of the atmosphere as you go upward.
The troposphere, the lowest layer, is right below the
stratosphere.
Ozone Layer : The ozone layer is a region in stratosphere that absorbs
most of the UV radiation coming from the Sun.
4.11 REFERENCES AND SUGGESTED FURTHER
READINGS
David Pimentel et al, Ecology of Increasing Disease Population growth and
environmental degradation. Bioscience Vol. 48 No. 1998
Leslie Roberts, Focus: Environmental degradation is contributing to health
threats worldwide. 1998
One Planet Many People: Atlas of Our Changing Environment (2005).
Powell, Fannetta. “Environmental Degradation and Human Disease”. Lecture.
Slide Boom. 2009. Web. Retrieved 2011-11-14.
Sharon Beder Environmental Principles and Policies 2006
ISBN 978-1-84407-40.
ANSWERS TO CHECK YOUR PROGRESS
1) Your answers must include the following points:
l Deforestation
l Industrialisation and release of harmful chemicals
l Environmental pollution
l Chemicals and pollutants in air and water
l Changing lifestyle
l Poor immunity
Check Your Progress Exercise 2
l One aspect of climate change
l Increase in average global temperature
l Flora and fauna not able to adapt.

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Environment and Ecology 2) Your answers must include the following points:
l Trapping of the sun’s radiations
l Essential for survival of life on this planet.
Check Your Progress Exercise 3
l Increase in temperature
l Effect on agriculture
l Diseases in human beings
l Decrease in oxygen
l Fish mortality
l Disruption in aquatic food chain and food web
l Loss of aquatic biodiversity

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Unit-4.pdf global enviroment issues and slow