Environmental Science and Technology

Course Topics

  • 1.0 Basics of Environmental Science
  • 1.1 Environmental Ethics & Interface with humans
  • 1.2 Genesis of Environmentalism
  • 2. Segments & Processes in the Environment
  • 2.1 Evolution & various factors in Environment
  • 2.2 Structure & Composition of Earth's Atmosphere
  • 2.3 Hydrological & Geochemical Cycle
  • 2.4 Geographical classification & Zones
  • 3. Principles of Ecology
  • 3.1 Tropic Structure & Energy Flow
  • 3.2 Complexity of Food web & patterns
  • 3.3 Forest Ecosystem & Agricultural Ecosystem
  • 3.4 Population Ecology
  • 3.5 Community Ecology
  • 3.5 Landscape Ecology
  • 3.6 Urban-Industrial Techno-Ecosystems
  • 4. Biodiversity & Conservation Biology
  • 4.1 Biodiversity - Meaning, Levels & influencing factors
  • 4.2 Biodiversity Hot-spot
  • 4.3 Global patterns of Biodiversity
  • 4.4 Aquatic, Terrestrial Flora & Fauna in India
  • 5. Environmental Microbiology
  • 5.1 Environmental Microbiology - Fundamental, Growth & Characteristics
  • 5.2 Microbiology of water
  • 5.3 Self Purification of water & Micro organisms
  • 5.4 Microbial Pollution of Water
  • 5.5 Water quality Assessment
  • 5.6 Indicators of water pollution
  • 5.7 Domestic Wastes and Treatment
  • 5.8 Beneficial Pathogenic Microbes in Agriculture
  • 6. Environmental Pollution & Its Control
  • 6.1 Air Pollution - Natural & Anthropogenic Sources
  • 6.2 Primary & Secondary Air Pollutants
  • 6.3 Pollution from Emission of Engines
  • 6.4 CFCs & HCFCs
  • 6.5 Methods of Monitoring & Controlling Air Pollution
  • 6.6 Air quality criterion and standards
  • 6.7 Effects of Air Pollution
  • 6.8 Air pollution Control concept
  • 6.9 Air Pollution Control system & devices
  • 7. Water Pollution
  • 7.1 Sources of water pollutants
  • 7.2 Surface & Ground water pollution
  • 7.3 Control of water pollution
  • 7.4 Industrial waste water control & management
  • 7.5 Marine Pollution - Source
  • 7.6 Marine Pollution Effects & Control
  • 7.7 Solid waste pollution
  • 7.8 Solid waste pollution management
  • 7.9 Bio-Medical Waste & E-Waste
  • 8. Environmental Audit
  • 8.1 Environmental Impact Assessment
  • 8.2 EIA Methodologies & Official guidelines
  • 8.3 Techniques for EIA
  • 8.4 Concept & Preparation of Environmental Impact Statement (EIS)
  • 8.5 Environmental Management Plan
  • 8.6 Environmental Audit - Guidelines & Methodologies
  • 8.7 Environmental Laws & Policies
  • 8.8 Public Liability Insurance Act, 1991
  • 8.9 Public Liability Insurance Act, 1991 - Provision, Relief & Penalties.
  • 9.0 MARPOL 73/38
  • 9.1 Annex 1
  • 9.2 Annex 2
  • 9.3 Annex 3
  • 9.4 Annex 4
  • 9.5 Annex 5
  • 9.6 Annex 6

1.0 Basics of Environmental Science

Concept of Environmental Science

Environmental science is the study of the interactions between the physical, chemical, and biological components of nature and also the relationships and effects of these components with the organisms in the environment

The field of environmental science can be divided into three main goals, which are

1. to learn how the natural world works,

2. to understand how we as humans interact with the environment, and 

3. to determine how we affect the environment.

The third goal of determining how humans affect the environment also includes finding ways to deal with these effects on the environment.

Importance of Environmental Science

At this current time, 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 and how they affect the world we live in.

Let's examine a major change that is currently occurring and its relationship to environmental science. The large change is the dramatic increase in the number of humans on earth.

For most of human history, the population has been less than a million people, but the current population has skyrocketed to over seven billion people. This equals out to seven thousand times more people!

Due to this increase in the human population, there has also been an increase in pressure on the natural resources and ecosystem services that we rely on for survival. Natural resources include a variety of substances and energy sources that we take from the environment and use.

Natural resources can be divided into renewable and nonrenewable resources. Renewable natural resources are substances that can be replenished over a period of time, such as sunlight, wind, soil, and timber.

On the other hand, nonrenewable natural resources are substances that are in finite supply and will run out. Nonrenewable resources include minerals and crude oils.

Due to the increase in the human population, natural resources are being used up at a more rapid rate than in the past. Although renewable natural resources can be replenished, when they are used too rapidly, they cannot be replenished fast enough to meet human demand.

Even worse, when nonrenewable natural resources are used too rapidly, they become closer to running out completely and being gone forever.

Natural resources have been referred to as the 'merchandise' produced by the environment, and in this respect, ecosystem services are the 'facilities' that we rely on to help produce the merchandise. 

Ecosystem services are the environment's natural processes that provide us with the resources we need to support life. Common ecosystem services include water and air purification, nutrient cycling, climate regulation, pollinating of plants, and the recycling of waste.

Just like some natural resources, ecosystem services are also limited and can be used up if not regulated.

Now, let's tie it together and think about population growth and its influence on both natural resources and ecosystem services. As the human population increases and natural resources and ecosystem services are used rapidly and potentially degraded, the future of humans on earth is in jeopardy.

This is one major example of why environmental science is important and valuable.


Some important definitions of environment are as under:

1. According to Boring, ‘A person’s environment consists of the sum total of the stimulation which he receives from his conception until his death.’ Indicating that environment comprises various types of forces such as physical, intellectual, mental, economical, political, cultural, social, moral and emotional.

2. Douglas and Holland defined that ‘The term environment is used to describe, in aggregate, all the external forces, influences and conditions, which affect the life, nature, behaviour and the growth, development and maturity of living organisms’.


The environment consists of four segments of the earth namely atmosphere, hydrosphere, lithosphere and biosphere:

1. Atmosphere:  The Atmosphere forms a distinctive protective layer about 100 km thick around the earth. A blanket of gases called the atmosphere surrounds the earth and protects the surface of earth from the Sun’s harmful, ultraviolet rays. It sustains life on the earth.  It also regulates temperature, preventing the earth from becoming too hot or too cold. It saves it from the hostile environment of outer space. The atmosphere is composed of nitrogen and oxygen besides, argon, carbon dioxide and trace gases.

 The atmosphere has a marked effect on the energy balance at the surface of the Earth. It absorbs most of the cosmic rays from outer space and a major portion of the electromagnetic radiation from the sun. It transmits only ultraviolet, visible, near infrared radiation (300 to 2500 nm) and radio waves. (0.14 to 40 m) while filtering out tissue-damaging ultra-violate waves below about 300 nm.

2. Hydrosphere: The Hydrosphere comprises all types of water resources oceans, seas, lakes, rivers, streams, reservoirs, polar icecaps, glaciers, and ground water. Oceans represent 97% of the earth’s water and about 2% of the water resources is locked in the polar icecaps and glaciers. Only about 1% is available as fresh water as surface water in rivers, lakes, streams, and as ground water for human use.

3. Lithosphere: Lithosphere is the outer mantle of the solid earth. It consists of minerals occurring in the earth’s crusts and the soil e.g. minerals, organic matter, air and water.

4. Biosphere: Biosphere indicates the realm of living organisms and their interactions with environment, viz atmosphere, hydrosphere and lithosphere.

The scope of environmental studies is very wide and it deals with many areas like i) Conservation of natural resources, ii) ecological aspects, iii) pollution of the surrounding natural resources, iv) controlling the pollution, v) social issues connected to it, and vi) impacts of human population on the environment.