Taxmann's Environmental Science | Theory Into Practice (I & II)

PREFACE TO SEVENTH EDITION

It gives us immense pleasure & satisfaction to present Seventh edition of “Environmental Science” to the teachers & students of Various Institutes. In this edition we have added topics in detail and practical/ exercises/experimental activities as per National Education Policy (NEP) syllabus. We have also added previous year questions and other important questions at the end of each chapter for reference.

All the topics mentioned in the new revised syllabus are organized briefly into seven chapters in very simple language understandable for students of diverse courses. Each chapter includes a broad introduction that provides conceptual outline followed by point-wise elucidation of each topic. The book is also inclusive with new case studies as per the latest syllabus for better understanding of issues related to environment.

This at the moment turned out to be an imperative educational resource and hope that it will be of value and interest to everyone seeking to broaden their understanding of the science behind environmental issues.

Environment Education cannot at all hang back fixed. It must revolutionize with the varying times which unavoidably amend our environment. So, vigorous criticism to improve the book and beneficial suggestions to take account of auxiliary topics are extremely welcomed at email id skbatra20@gmail.com.

SANJAY KUMAR BATRA, KANCHAN BATRA & HARPREET KAUR

NATURAL RESOURCES

PAPER - JANUARY 2023 (AEC – 1, UGCF),

ENVIRONMENTAL SCIENCE PAPER - JULY 2023 (AEC-1, UGCF),

- 1, UGCF),

ENVIRONMENTAL SCIENCE PAPER - JANUARY 2024 (AEC - 1, UGCF),

- III

ENVIRONMENTAL SCIENCE PAPER - MAY 2024 (AEC -1, UGCF), SEM. - II P.21

INTRODUCTION TO ENVIRONMENTAL STUDIES

GENERAL BACKGROUND

The term ‘Environment’ has been derived from the French word “Environ” which means to encircle or surround. Environment literally means surrounding in which we are living. Environment means all living components like plants and animals and non-living components like water, air etc. surrounding us. It includes all those things on which we are directly or indirectly dependent for our survival. Environmental Protection Act (1986) defined, “Environment as the sum total of water, air and land, their inter-relationship among themselves and with the human beings, other living beings and property.”

Environmental studies envisage study of interactions of the physical, chemical and biological components of the environment and also the relationships and effects of these components with the organisms in the environment. Environmental sciences apply interdisciplinary approach for understanding the different aspects of environment and to address the environmental issues and problems. A brief idea of environmental issues and their interlinked nature is depicted in figure 1.1.

WASTE PRODUCTION

(a) Solid Waste

(b) Hazardous Waste

POLLUTION

(a) Air

(b) Water

(c) Soil

Major Environmental Issues

BIODIVERSITY DEPLETION

(a) Deforestation

(b) Desertification

(c) Habitat Destruction

(d) Extinction

CLIMATE CHANGE

(a) Global warming

(b) Abnormal weather conditions

Figure 1.1

Fundamentally, all environmental problems involve either depletion of resources (consumption) or pollution of sinks (production of waste) as seen from the above figure. Therefore, study of these aspects and finding a sustainable solution to these problems comes under the purview of environmental studies.

The field of environmental science study can be divided into three main areas:

1. To learn how the natural world works.

2. To understand how we as humans interact with the environment.

3. To determine how we affect the environment.

Environment study deals with the analysis of the processes in water, air, land, soil and organisms which leads to pollute or degrade environment. It helps us for establishing standard for safe, clean and healthy natural ecosystem. It also deals with important issues like safe and clean drinking water, hygienic living conditions and clean and fresh air, fertility of land, healthy food and development.

1.1 MULTI-DISCIPLINARY NATURE OF ENVIRONMENTAL STUDIES

Since, the environment is complex and actually made up of many different environments, including natural, constructed and cultural environments, environmental studies is the inter disciplinary examination of how biology,

geology, politics, policy, studies, law, religion, engineering, chemistry and economics combine to inform the consideration of humanity’s effects on the natural world (Figure 1.2).

Geography, Economics, Political Science, Law

Earth sciences (a) Geology (b) Weather and climatic conditions

Environmental Studies

Philosophy, Ethics

Atmospheric Sciences, Ecology, Biology, Environmental Chemistry

Figure 1.2

It is essentially a multi-disciplinary approach and its components include Biology, Geology, Chemistry, Physics, Engineering, Sociology, Medical Sciences, Anthropology, Economics, Statistics, Philosophy etc. Role of different branches can be summarized as (Table 1.1):

Physics : To understand the change of material and energy interaction and to make mathematical models of environment.

Chemistry : To understand the molecular interactions in the system.

Biology : To describe the effects within the plant and animal kingdom and their diversity.

Atmospheric Science : To examine the phenomenology of the Earth’s gaseous outer layer. It comprises meteorological studies, greenhouse effect, airborne contaminants, sound propagation phenomena related to noise pollution, and even, light pollution.

Ecology : To analyse the dynamics among an interrelated set of populations, or a population and some aspects of its environment. These studies could be on endangered species, predator interactions, effects upon populations by environmental contaminants etc.

Environmental Chemistry : To study the chemical alterations in the environment. Principal areas of study include soil contamination and water pollution. The topics of analysis involve chemical degradation in the environment, multi-phase transport of chemicals and chemical effects upon biota.

Geo-science : It includes environmental geology, environmental soil science, volcanic phenomena and evolution of the earth’s crust.

Mathematics and Computer Science : Used in environmental modelling and analysis of environment related data.

Economics : It deals with economical aspects of various components of environment.

Law : It helps in framing of environment related laws, acts, rules and their monitoring.

Social Science: It helps in dealing with population and health related issues.

Table 1.1. Illustration of Interdisciplinary Nature of Environmental Science: Air Pollution

Environmental issueMajor subject

Nature and reaction of air pollutantsChemistry and Chemical Engineering

Effects of air pollutants on human beings, animal and plants

Zoology and Botany and various branches of Life Science

Effect of air pollutants on materials Meteorology, Thermodynamics, Geography

Effect of climate on air pollutionMathematical modelling etc.

Air pollution control systemsPhysics, Chemistry and various branches of Engineering

History of air pollution and air pollution episodes History

Economic impact of air pollutionEconomics, Demography

Sociological impact of air pollutionSociology

Alternative fuelsVarious branches of Physical Sciences

Conservation of resources and pollution control Various branches of Physical and Political Science

Ozone hole and global warming Almost all fields under the sun have got something to contribute to the understanding and prevention of these phenomenons.

1.2 COMPONENTS OF ENVIRONMENT

Environment may be regarded as a ‘space’ or a ‘field’ in which networks of interactions between different entities occurs. A detailed discussion of components of environment is given below:

Atmosphere

The atmosphere can be divided into layers based on its temperature. Atmosphere comprises of mixture of gases and is divided five layers i.e. troposphere, stratosphere, mesosphere, thermosphere and exosphere. The atmosphere grows thinner (less dense) as one moves upward from Earth’s surface. It gradually gives way to the vacuum of outer space.

A brief discussion of these layers is given below:

Troposphere

This is the lowest part of the atmosphere. Troposphere means “region of mixing” and is so named because of vigorous convective air currents within the layer. It contains most of our weather - clouds, rain, snow. In this part of the atmosphere the temperature gets colder as the distance above the earth increases, by about 6.5°C per kilometre. The troposphere contains about 75% of all of the air in the atmosphere, and almost all of the water vapour (which forms clouds and rain). The decrease in temperature with height is a result of the decreasing pressure.

The lowest part of the troposphere is called the boundary layer. This is where the air motion is determined by the properties of the Earth’s surface. Turbulence is generated as the wind blows over the Earth’s surface, and by thermals rising from the land as it is heated by the sun. This turbulence redistributes heat and moisture within the boundary layer, as well as pollutants and other constituents of the atmosphere.

The top of the troposphere is called the tropopause. This is lowest at the poles, where it is about 7-10 km above the Earth’s surface. It is highest (about 17-18 km) near the equator.

Stratosphere

This extends upwards from the tropopause to about 50 km. It contains 90% of the total ozone in the atmosphere. The increase in temperature with height occurs because of absorption of ultraviolet (UV) radiation from the sun by this ozone. Temperatures in the stratosphere are highest over the summer pole, and lowest over the winter pole.

The ozone layer is present between an altitude of 15-25 km. Ozone absorbs the bulk of solar ultraviolet radiation in wavelengths from 290 nm - 320 nm (UV-B radiation). These wavelengths are harmful to life because they can be

Figure 1.3

absorbed by the nucleic acid in cells. By absorbing dangerous UV radiation, the ozone in the stratosphere protects us from skin cancer and other health damage. However chemicals (called CFCs or freons, and halons) which were once used in refrigerators, spray cans and fire extinguishers have reduced the amount of ozone in the stratosphere, particularly at polar latitudes, leading to the so-called “Antarctic ozone hole”. Now humans have stopped making most of the harmful CFCs we expect the ozone hole will eventually recover over the 21st century, but this is a slow process.

Mesosphere

The region above the stratosphere is called the mesosphere. Here the temperature again decreases with height, reaching a minimum of about -90°C at the “mesopause”.

The stratosphere and mesosphere together are sometimes referred to as the middle atmosphere.

Thermosphere

The thermosphere lies above the mesopause, and is a region in which temperatures again increase with height. This temperature increase is caused by the absorption of energetic ultraviolet and X-Ray radiation from the sun.

The Exosphere

The exosphere is derived from ancient Greek word meaning outside or beyond sphere. The region above about 500 km is called the exosphere. The exosphere is the very edge of our atmosphere. This layer separates the rest of the atmosphere from outer space. It’s about 6,200 miles (10,000 kilometers) thick. It contains mainly oxygen and hydrogen atoms, but they are very spread out. There is a lot of empty space in between. There is no air to breathe, and it’s very cold.

Ionosphere

A layer of the atmosphere above about 80 km is called the ionosphere and it overlaps the mesosphere, thermosphere and exosphere. It’s a very active part of the atmosphere, and it grows and shrinks depending on the energy it absorbs from the sun. Ionosphere is named so because of the gases in these layers are excited by solar radiation to form “ions” with a positive charge. The temperature of the thermosphere varies between night and day and between the seasons, as do the numbers of ions and electrons which are present. The ionosphere reflects and absorbs radio waves, allowing us to receive shortwave radio broadcasts.

Lithosphere:

The lithosphere refers to outer solid part of the earth. It includes the earth’s mantle and crust. The oceanic lithosphere constitutes the oceanic crust and exists in oceanic basins. Similarly, Continental lithosphere deals with crust which covers the Earth’s landmass. The lithosphere shields living organisms from the heat of the Earth’s core. Lithosphere is surrounded by the atmosphere above and asthenosphere underneath.

The actual thickness of the lithosphere varies considerably and can range from 40 km to 100 km. The lithosphere ends at the point when the minerals in the earth’s crust begin to demonstrate viscous and fluid behaviours. The exact depth at which this happens depends on the chemical composition of the earth, and the heat and pressure acting upon the material. The lithosphere is divided into seven major and eight minor tectonic plates that fit together around the earth like a jagged puzzle. Major tectonic plates are Pacific plate, North American Plate, Eurasian Plate, African Plate, Antarctic Plate, Indo-Australian Plate, South American Plate, Minor plates include Caribbean, Cocos, Eurasian, Indian, Juan de Fuca, Nazca, North American, Pacific, Philippine, Scotia, and South American Plates.

These tectonic plates keep on moving slowly. The friction created when these tectonic plates push against one another cause earthquakes, volcanoes and the formation of mountains and ocean trenches.

The Hydrosphere

The hydrosphere is composed of all of the water on or near the planet’s surface. Hydrosphere is composed of oceans, rivers, and lakes, as well as underground aquifers and the moisture in the atmosphere. Scientists estimate the total amount at more than 1,300 million cubic feet.

More than 97 per cent of the earth’s water is found in its oceans. The remainder is freshwater, two-thirds of which is frozen within the earth’s polar regions and mountain snow packs. The planet’s water doesn’t exist in a static environment; it changes from as it moves through the hydrological cycle. It falls to the earth in the form of rain, seeps into underground aquifers, rises to the surface from springs or seeps from porous rock, and flows from small streams into larger rivers that empty into lakes, seas, and oceans, where some of it evaporates into the atmosphere to begin the cycle anew.

The Biosphere

The biosphere (Greek word bios means life, Sphaira means sphere) refers to all living organisms from plants to bacteria to multicellular organisms. Most of the planet’s terrestrial life is found in a zone that stretches from 3

meters below ground to 30 meters above it. Most aquatic life inhabits a zone that stretches from the surface to about 200 meters below in the oceans and seas. But some creatures can live far outside of these ranges: some birds are known to fly as high as 8 kilometers above the earth, while some fish have been found as deep as 8 kilometers beneath the ocean surface. Micro-organisms are also known to survive well beyond even these ranges. The biosphere is made up of biomes, which are areas where plants and animals of a similar nature can be found together. A desert, with its cactus, sand, and lizards, is one example of a biome. A coral reef is another.

1.3 ENVIRONMENTAL STUDY: SCOPE AND IMPORTANCE

Humanity has neglected to acknowledge the tremendous benefits nature provides. It’s impossible to truly estimate the real value of nature. For example, forests prevent soil erosion, landslides, and flooding; maintain the purity of the air and water; affect local and global rainfall; temper climatic fluctuations; and promote watersheds and biodiversity. It is impossible from our side to really gauge the real value of environment because it’s a real complex system. Just concentrating on one iconic aspect won’t lead us to correct assessment of environment’s importance. Other ecosystems like mangroves, wetlands, grasslands, shrubs, deserts, oceans, coral reefs, tundra-arctic regions, and so on provide similar and unique benefits.

Scope of Environmental studies:

Environmental studies has multiple and multi-level scopes:

1. Conservation of ecosystem and biodiversity

2. Prevention and control of pollution

3. Management of natural resources

4. Impacts of human population on the environment.

Environmental studies give a great importance to the environmental impacts (alteration of natural environment) cased due to human activities. There are basically two different types of environmental impacts; (a) resource depletion, and (b) pollution. For assessing the gravity of these problems and finding their solutions, environmental science study is the way out.

The world around us is changing at a very rapid pace. Some changes are beneficial, but many of the changes are causing damage to our planet. The field of environmental science is a valuable resource for learning more about these changes. Finding solutions to environmental problems involves collecting the data as well as finding a scientific, social and logical solution to the problem.

According to UNESCO (1971), the objectives of environmental studies are:

(a) To impart basic knowledge about the environment and its allied problems.

(b) To create the awareness about environmental problems among peoples.

(c) To develop an attitude of concern for the environment.

(d) Motivate public to participate in environment protection and environment improvement.

(e) Help acquiring skills to assist the concerned individuals in identifying and solving environmental problems.

(f) To suggest the pathways to attain harmony with nature.

Importance of environmental studies

The importance of environmental studies is described as follows:

1. Clarification of modern environmental concept like how to conserve biodiversity.

2. Helping people know the more sustainable way of living.

3. Making masses understand how to use natural resources more efficiently.

4. Developing awareness about the behaviour of organism under natural conditions.

5. Creating knowledge about the inter-relationship between organisms in populations and communities.

6. Creating awareness and educating people regarding environmental issues and problems at local, national and international levels.

1.4 CONCEPT OF SUSTAINABILITY AND SUSTAINABLE DEVELOPMENT

Sustainability is derived from the Latin word sustinere i.e., to hold and sustain. Sustain is to maintain. It is related to the quality of life in a community - whether the economic, social and environmental systems that make up the community are providing a healthy, productive, meaningful life for all community residents, present and future.

Sustainability can be defined as the practice of maintaining processes of productivity (natural or human made) indefinitely by replacing resources used with resources of equal or greater value without degrading or endangering natural biotic systems.

Sustainable Development

The concept of sustainable development has two related concepts, i.e., the right to develop and the need to sustain the environment, which need to be balanced for achieving future development in a sustainable manner. It is the practice of developing land and construction projects in a manner that reduces their impact on the environment by creating energy efficient models. This can take the form of installing solar panels or wind generators on factory sites, using geothermal heating techniques or even participating in cap and trade agreements. The biggest criticism of sustainable development is that it does not do enough to conserve the environment in the present and is based on the belief that the harm done in one area of the world can be counter balanced by creating environmental protections in the other. According to Brundtland Commission in its 1987 report “Our Common Future”.

“Sustainable development is development that meets the needs of the present, without compromising the ability of future generations to meet their own needs.”

Sustainable development has three goals: to minimize the depletion of natural resources, to promote development without causing harm to the environment and to make use of environmentally friendly practices. This implies that we need to look after our planet, our resources and our people to ensure that we can live in a sustainable manner and that we can regenerate, maintain and improve planetary resources for use by future generations. Sustainable development is the organizing principle for sustaining finite resources necessary to provide for the needs of future generations of life on the planet. It is a process that predicts a desirable future state for human societies in which living conditions and resource-use continue to meet human needs without undermining the “integrity, stability and beauty” of natural biotic system.

Four dimensions of the sustainability are economic, ecological, political and cultural sustainability. The first three domains were endorsed by the United Nations Millennium Deceleration i.e., economic, environment and social sustainability. So to achieve true sustainability we need to balance economic, social and environmental sustainability factors in equal harmony. These may be defined as:

Environmental Sustainability: The environment supports our life system. The human behaviour impacts the environment and we either nurture or mistreat it. Mahatma Gandhi aptly stated, “Earth provides enough to satisfy every man’s need, but not for every man’s greed”. The harsh fact is that humans continue to consume natural resources at a destructive pace. Environmental sustainability means that we are living within the means of our natural resources. To live in true environmental sustainability we need

to ensure that we are consuming our natural resources, such as materials, energy fuels, land, water etc., at a sustainable rate. Presently, the exhaustible resources are over utilized rapidly. The speed of exploitation of renewable resources is faster than their regenerative capacity. This results in problem for present as well as future generations. Technology can be used to replace non-renewable or exhaustible mineral resources by the augmentable resources. Moreover, non-renewable energy resources should be depleted at slower pace enabling transition to renewable energy resources. Development should be synonymous with environmental protection and sustainable use of natural resources. Environmental sustainability should not be confused with full sustainability, which also needs to balance economic and social factors.

EconomyEnvironment

Society

Figure 1.4: A view of community as three separate, unrelated parts: an economic part, a social part and an environmental part The environmental policies have a deep effect on the development process while the development process damages the whole environment system. Factors like, urbanization, industrialization, population growth, poverty etc. increases the demand of resources resulting in resource depletion. There are dangerous effects of mindless development like, effect of gases on ozone layer, greenhouse effects, global warming, decrease in forest cover, water and land pollution, effects of burning of fossil fuel etc.

Environmental sustainability and sustainable development are one and the same; there is quite a few ways in which they differ in their goals. They have the same overall goal that of conserving natural resources etc. but their priorities of actions are different. In a way, “Sustainable development is the pathway to sustainability”.

For instance, there will be disagreements when it comes to developing construction practices on a wetland. The environmental sustainability focus would argue that the preservation of the wetland is more important than

everything else. Sustainable development will show that by incorporating preservation areas, and contributing to the overall preservation of a different wetland area that the damage is balanced out. Sustainable development will also argue that the local economic benefits will lead to more funding to create environmental protection areas elsewhere.

Economic Sustainability: Economic sustainability requires that a business or country uses its resources efficiently and responsibly so that it can operate in a sustainable manner to consistently produce an operational profit. Without an operational profit a business cannot sustain its activities. Without acting responsibly and using its resources efficiently a company will not be able to sustain its activities in the long term. An economically sustainable system must also be able to produce goods and services on a continuing basis, to maintain manageable levels of government and external debt, and to avoid extreme sectoral imbalances which damage agricultural or industrial production.

Social Sustainability: A socially sustainable system must achieve fairness in distribution and opportunity, adequate provision of social services including health and education, gender equity, and political accountability and participation. Social sustainability is the ability of society, or any social system, to persistently achieve a good social well-being. Achieving social sustainability ensures that the social well-being of a country, an organisation, or a community can be maintained in the long term.

Taking these three pillars of sustainability further if we only achieve two out of three pillars then we end up with:

Social + Economic Sustainability = Equitable

Social + Environmental Sustainability = Bearable

Economic + Environmental Sustainability = Viable

Only through balancing economic + social + environmental can we achieve true sustainability and a truly circular economy.

Resolving these differences can be difficult. Very often, money and economy will prove to be the deciding factor. This doesn’t mean that one side loses and one side wins, but the environmental factors can influence the development design to create an approach that provides the best of both worlds, without completing adopting one approach over the other.

Essential Conditions for achieving Sustainable Development

The essential requirements of facilitating overall sustainable development are:

a. The human needs should not be beyond the capacity of environment to support it. Reduce poverty and ensure equality of opportunity and equitable distribution of assets. Invest in health and education.

b. Participation of indigenous communities, women, tribes etc. in development process.

c. Effective waste management and pollution control and access to clean energy produced in a sustainable manner. Preserve marine life from ill effects of pollution and climate change. Resilience to natural disasters and control use of hazardous materials.

Symptoms of Unsustainability

The symptoms of unsustainability are:

a. Ecological Symptom: Depletion of ozone layer, global warming, acid rain, extinction of species and declining forest cover etc.

b. Economic Symptom: Economic tension, intra-generational and inter-generational inequities.

c. Social Symptom: Wars and social disturbances resulting in mass destruction.

Causes of Unsustainability

The causes of unsustainability are:

a. Population explosion and discrepancy in population and distribution of natural resources.

b. Higher per capita environmental demand and excessive demand of natural resources like oil, coal, wood etc. and reduction in biodiversity.

c. Political and economic mismanagement and greedy desire to exploit nature.

Indicators of Sustainability:

The indicators of sustainability are mentioned below:

a. GDP Growth : Higher total production growth rate facilitates employment, price stability and material welfare. An indicator of sustainability, it helps in eliminating poverty.

b. Population instability and Water Availability: Over population leads to over-exploitation of resources and is a hindrance in sustainability. Availability of sufficient water for consumption, industrial and agricultural use is to be ensured.

c. Clean Air Index and Energy Resources: Pure and clean air is essential for survival of human beings and other species. Air pollution, acid rain and greenhouse effects are threats for sustainability. To achieve long-term sustainability use of renewable sources must be lower than its rate of regeneration.

Environmental Science | Theory Into Practice (I & II)

AUTHOR : SANJAY KUMAR BATRA, KANCHAN BATRA, HARPREET KAUR

PUBLISHER : TAXMANN

DATE OF PUBLICATION : JUNE 2024

EDITION : 7TH EDITION

ISBN NO : 9789357789820

NO. OF PAGES : 456

BINDING TYPE : PAPERBACK

Description

Rs. 625 | USD 8

This comprehensive and authentic book on ‘Environmental Studies’ is a valuable educational resource for anyone interested in understanding environmental science. It is tailored for students of Environmental Science at the undergraduate level (AEC-I) based on the UGCF for the University of Delhi and those in the Non-Collegiate Women’s Education Board, the School of Open Learning, and various central universities across India.

The Present Publication is the 7th Edition, authored by Dr. Sanjay Kumar Batra, Dr. Kanchan Batra & Prof. Harpreet Kaur, with the following noteworthy features:

u [Presentation] Subject matter is presented in a simple, systematic manner with comprehensive explanations

u [Case Studies and Success Stories] Includes both Indian and global case studies along with entrepreneurial success stories

u [Key Topics] Environment policies, human population growth, G20 Summit, ecosystems, natural resources, biodiversity, disaster management, greenhouse effect, and endangered species

u [Environmental Issues] Addresses pollution, ozone layer depletion, global warming, and biodiversity conservation

u [Questions and Exercises] Provides review questions, subjective and objective type questions, practical exercises, experiential activities, and outreach activities

u [Exam Preparation] Includes past exam question papers from 2020 to 2024 to aid exam preparation.

The book is developed with a student-oriented approach shaped by the authors’ teaching experiences and interactions. Each chapter begins with a broad introduction, followed by a detailed, point-wise discussion of each topic, and includes new case studies relevant to the latest syllabus to enhance understanding.