Environmental science is a multi-disciplinary field that studies the interactions between the natural world and human activities. It includes aspects of chemistry, physics, biology and other disciplines. The document discusses key concepts in environmental science including the components of the environment like the atmosphere, hydrosphere, lithosphere and biosphere. It also discusses ecosystems, food chains and food webs, producers and consumers, and energy flow between trophic levels. The goal of environmental science is to understand how nature works and how human activities affect the environment.

1. JAI SHRIRAM ENGINEERING COLLEGE, TIRUPPUR – 638 660
Approved by AICTE, New Delhi & Affiliated to Anna University, Chennai
Recognized by UGC & Accredited by NAAC and NBA (CSE and ECE)
GE 3451 ENVIRONMENTAL SCIENCE AND ENGINEERING
B.SARITHA
Department of Electronics And Communication Engineering

2. Environmental Science
The science of Environment
studies is a multi-disciplinary
science
It comprises various branches of
studies like chemistry, physics,
medical science, life science,
agriculture, public health, sanitary
engineering etc.

3. Environmental Science
• Environmental science is the study of:
– How the natural world works
– How the environment affects humans and vice versa

4. Environment: the total of our
surroundings
All the things around us with which we interact:
Biotic vs. Abiotic
Living things
Animals, plants, forests, fungi, etc.
Nonliving things
Continents, oceans, clouds, soil, rocks
Our built environment
Buildings, human-created living centers
Social relationships and institutions

5. Environment
Environment means the surrounding external conditions
influencing development or growth of people, animal or
plants; living or working conditions.
This involves three questions:
1. What is Surrounded
2. By what Surrounded
3. Where Surrounded

6. Definitions of Environment
 A person’s environment consists of the sum total of the
stimulation which he receives from his conception until his
death.’
 The term environment is used to describe, in the aggregate,
all the external forces, influences and conditions, which
affect the life, nature, behaviour and the growth,
development and maturity of living organisms.’

7. The importance of environmental
awareness
 Environmental awareness is critical because it can help to
minimise pollution and global warming.
 It can also lead to a more sustainable world by promoting
renewable resources such as solar, wind, and water.

8. The goals of Environmental Science are
Learn how nature works
Learn how the environment affects us
Learn how we affect the environment
Learn how to deal with environmental problems
and live more sustainably.

9. Scope of Environment
The environment consists of four segments as under:
1. Atmosphere
2. Hydrosphere
3. Lithosphere
4. Biosphere

10. • Geoshpere
(Lithosphere):
Crust: < 1% (Thin)
Everest: 8.85
km
Mantle, Cores
•Hydrosphere:
(oceans)
Mariana Trench
(6.9mi)
~ 0.2 %
• Atmosphere: ~1%:
30 km (99% of air)
extends to 120 km
• Biosphere:
Planet Earth

11. Atmosphere
The atmosphere implies the protective blanket of gases,
surrounding the earth:
(a)It sustains life on the earth.
(b)It saves it from the hostile environment of outer space.
(c)It absorbs most of the cosmic rays from outer space and a
major portion of the
electromagnetic radiation from the sun.
(d)It transmits only here ultraviolet, visible, near infrared
radiation (300 to 2500
nm) and radio waves. (0.14 to 40 m) while filtering out tissue-
damaging ultraviolate
waves below about 300 nm.

12. Hydrosphere
The Hydrosphere comprises all types of water resources oceans,
seas, lakes, rivers, streams, reserviour, polar icecaps, glaciers, and
ground water.
(i) Nature 97% of the earth’s water supply is in the oceans,
(ii)About 2% of the water resources is locked in the polar icecaps
and glaciers.
(iii)Only about 1% is available as fresh surface water-rivers, lakes
streams, and ground water fit to be used for human consumption
and other uses.

13. 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.

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

15. Element of Environment
(1) Physical elements
 Physical elements are as space, landforms, water bodies, climate
soils, rocks and minerals.
 They determine the variable character of the human habitat, its
opportunities as well as limitations.
(2) Biological elements
Biological elements such as plants, animals, microorganisms and
men constitute the biosphere.
(3) Cultural elements
Cultural elements such as economic, social and political elements
are essentially manmade features

16. ENVIRONMENT STUDIES: IMPORTANCE
 The environment studies enlighten us, about the
importance of protection and conservation of our
indiscriminate release of pollution into the environment
 At present a great number of environment issues, have
grown in size and complexity day by day, threatening the
survival of mankind on earth. We study about these issues
besides and effective suggestions in the Environment
Studies.

17. IMPORTANCE
Environment studies have become significant for the
following reasons:
1. Environment Issues Being of International
Importance
2. Problems Cropped in The Wake of Development
3. Explosively Increase in Pollution
4. Need for An Alternative Solution
5. Need To Save Humanity From Extinction
6. Need For Wise Planning of Development
7. Misra’s Report

18. Misra’s Report
• Misra (1991) recognized four basic principles
of ecology, as under:
• (i) Holism
• (ii) Ecosystem
• (iii) Succession
• (iv) Conversation

19. Misra (1991) has recognised four basic
requirements of environmental management as
under:
(i) Impact of human activities on the environment,
(ii) Value system,
(iii) Plan and design for sustainable development,
(iv) Environment education.

20. NEED FOR PUBLIC AWARENESS
Some of the challenges are as under
1. Growing Population
2. Poverty
3. Agricultural Growth
4. Need to Ground water
5. Development And Forests
6. Degradation of Land
7. Reorientation of Institutions
8. Reduction of Genetic Diversity
9. Evil Consequences of Urbanisation
10. Air and water Pollution

21. VARIOUS TYPES OF ENVIRONMENT
According to Kurt Lewin, environment is of
three types which influence the personality of
an individual as under:
(a) Physical Environment,
(b) Social and Cultural Environment, and
(c) Psychological Environment.

22. STRUCTURE OF ENVIRONMENT
Environment is both physical and biological. It includes
both living and non-living components.
(i) Physical Environment- The Physical Environment is
classified into three broad categories viz.
(a) Solid,
(b) Liquid
(c) Gas.
(ii) Biological Environment
The biological of the environment consists of:
(a) Plants (flora)
(b) Animals (fauna).

23. Sustainable development
Sustainable development: the use of
resources to satisfy current needs without
compromising future availability of resources
for generations to come
Sustainability
Leaves future generations with a rich and full
Earth
Conserves the Earth’s natural resources
Maintains fully functioning ecological systems of
nature

24. Conclusion
Environmental science helps us understand our
relationship with the environment and informs
our attempts to solve and prevent problems.
Identifying a problem is the first step in solving it
Solving environmental problems can move us
towards health, longevity, peace and prosperity
Environmental science can help us find balanced
solutions to environmental problems for
sustainable development
3rd Mtg end (8/26/08)

25. ECOLOGY
• Ecology is the study of the interactions between an organism
of some kind and its environment
ECOSYSTEM:
“Eco-system is defined as a self regulating group of
biotic communities of species interacting with their non
living environment exchanging energy and matter.”

26. STRUCTURE &TYPES OF ECOSYSTEM

28. Producers provide energy for
other organisms in an ecosystem.
Producers = Plants
Producers are also
known as autotrophs.
Producers need
sunlight to make food.
The sun is their main
source of energy.
Consumers=
Everything else!
Consumers are also
known as
heterotrophs.
Energy flows from
producers to
consumers.

29. Producer or Consumer?
!

30. Producer or Consumer?

31. Producer or Consumer?

32. Producer or Consumer?

33. Producer or Consumer?

34. Producer or Consumer?

35. Almost all producers obtain energy
from sunlight.
• Chemosynthesis
– In 1977, scientists
discovered the first
prokaryotes (archaea)
that did NOT need
sunlight to make food.
– Instead, these
prokaryotes utilized
the chemicals in the
water to form
carbohydrates—this is
called chemosynthesis.

36. Food Chains and Food
Webs

37. Food Chains
• A food chain is a
sequence that
links species by
their feeding
relationships.

38. Types of Consumers
• Herbivores
– Eat only plants
• Carnivores
– Eat only meat (includes
insects)
• Omnivores
– Eat both plants and animals
(includes insects)
• Detritivores
– Eat detritus, or dead organic
matter
• Decomposers
– Are detritivores that break
down organic matter into
simpler compounds

39. Types of Consumers
• Specialist
– A consumer
that primarily
eats one
specific
organism or
feed on a
very small
number of
organisms.
• Generalist
– Consumers
that have a
varying diet.
Giant Pandas are
specialists. Over 95% of
their diet comes from
bamboo. If bamboo
became scarce, the
Panda would be in
danger of extinction.
Raccoons are
generalists.
They can live
almost
anywhere, and
eat almost
anything.

40. Trophic Levels
• Trophic levels
are the levels
of
nourishment
in a food
chain.

41. food webs
 A food web is a
model that shows
the complex
network of feeding
relationships and
the flow of energy
within and
sometimes beyond
an ecosystems.
At each link in a
food web, some
energy is stored
within an organism,
and some energy is
dissipated into the
environment.

42. Food Webs
• The stability of any
food web depends
on the presence of
producers, as they
form the base of the
food web.
The mouse is both a primary and
secondary consumer because it
eats both plants and insects in
this food web.

43. Pyramid Models

44. An energy pyramid shows the
distribution of energy among trophic
levels.
• Sunlight provides the energy for
photosynthesis, and that energy flows up
the food chain. Along the way, some of the
energy is dissipated, or lost.

45. Loss of Available Energy
Biomass is a measure of the total mass of organisms in a
given area.
 When a consumer incorporates the biomass of a producer to its
own biomass, a great deal of energy is lost in the process as
heat and waste.
The dissipation, or loss, of energy from one trophic level to the next
may be as much as 90%.
Only 10% of the available energy is left to transfer from one trophic
level to the next.

46. Energy Pyramids
• Because energy is lost at
each stage of a food
chain, the longer the
chain is, the more energy
is lost overall.
– The total energy used by
producers far exceeds
the energy used by the
consumers they support.
– An energy pyramid is a
diagram that compares
the energy used by
producers, primary
consumers, and other
trophic levels.

47. Other pyramid models illustrate an
ecosystem’s biomass and distribution
of organisms.
• Biomass pyramid
– Diagram that
compares the biomass
of different trophic
levels within an
ecosystem.
• Pyramid of numbers
– Shows the number of
individual organisms at
each trophic level in an
ecosystem.
5,000,0000
500,000
5,000
5

48. Energy in Ecosystems

49. Producer or Consumer?
!

50. Producer or Consumer?

51. Producer or Consumer?

52. Producer or Consumer?

53. Producer or Consumer?

54. Almost all producers obtain energy
from sunlight.
• Chemosynthesis
– In 1977, scientists
discovered the first
prokaryotes (archaea)
that did NOT need
sunlight to make food.
– Instead, these
prokaryotes utilized
the chemicals in the
water to form
carbohydrates—this is
called chemosynthesis.

55. Food Chains and Food
Webs

56. Types of Consumers
• Herbivores
– Eat only plants
• Carnivores
– Eat only meat (includes
insects)
• Omnivores
– Eat both plants and animals
(includes insects)
• Detritivores
– Eat detritus, or dead organic
matter
• Decomposers
– Are detritivores that break
down organic matter into
simpler compounds

57. Types of Consumers
• Specialist
– A consumer
that primarily
eats one
specific
organism or
feed on a
very small
number of
organisms.
• Generalist
– Consumers
that have a
varying diet.
Giant Pandas are
specialists. Over 95% of
their diet comes from
bamboo. If bamboo
became scarce, the
Panda would be in
danger of extinction.
Raccoons are
generalists.
They can live
almost
anywhere, and
eat almost
anything.

58. Trophic Levels
• Trophic levels
are the levels
of
nourishment
in a food
chain.

59. Trophic Levels
Producers
 Basis of all trophic
levels.
Primary consumers
 herbivores
Secondary consumers
 carnivores that eat
herbivores.
Tertiary consumers
 carnivores that eat
secondary consumers.
Omnivores
 May be listed at
different trophic levels
in different food
chains.

60. food webs
 A food web is a
model that shows
the complex
network of feeding
relationships and
the flow of energy
within and
sometimes beyond
an ecosystems.
At each link in a
food web, some
energy is stored
within an organism,
and some energy is
dissipated into the
environment.

61. Food Webs
• The stability of any
food web depends
on the presence of
producers, as they
form the base of the
food web.
The mouse is both a primary and
secondary consumer because it
eats both plants and insects in
this food web.

62. Pyramid Models

63. An energy pyramid shows the
distribution of energy among trophic
levels.
• Sunlight provides the energy for
photosynthesis, and that energy flows up
the food chain. Along the way, some of the
energy is dissipated, or lost.

64. Loss of Available Energy
Biomass is a measure of the total mass of organisms in a
given area.
 When a consumer incorporates the biomass of a producer to its
own biomass, a great deal of energy is lost in the process as
heat and waste.
The dissipation, or loss, of energy from one trophic level to the next
may be as much as 90%.
Only 10% of the available energy is left to transfer from one trophic
level to the next.

65. Energy Pyramids
• Because energy is lost at
each stage of a food
chain, the longer the
chain is, the more energy
is lost overall.
– The total energy used by
producers far exceeds
the energy used by the
consumers they support.
– An energy pyramid is a
diagram that compares
the energy used by
producers, primary
consumers, and other
trophic levels.

66. • https://drive.google.com/file/d/1D5iEJ7RP1iU
zPBPiXjFsD5xx9xlbV31J/view
• https://drive.google.com/file/d/1D5iEJ7RP1iU
zPBPiXjFsD5xx9xlbV31J/view