Our environment consists of living and non-living components that interact in complex ways. Humans rely on healthy ecosystems, but our activities have disrupted natural cycles and caused pollution. Key issues include climate change from greenhouse gas emissions, which risks a runaway warming effect. While scientists agree human activity contributes to current warming trends, fully predicting climate impacts remains challenging given its complexity. Maintaining sustainable resource use requires understanding our role within natural systems.

1. OUR ENVIRONMENT

2. OUR ENVIRONMENT
 What is Environment ?
 Our Environment is our surrounding. This includes
living and non-living things around us.
 The non-living components of environment are land,
water and air.
 The living components are germs, plants, animals and
people.

3. Environmental Science
• Environmental Science is the oldest
science.
• The scientific knowledge started
developing since the time the humane
being started observing the surrounding
environment.
• In the modern curriculum also the first
subject taught on science is Environmental
Science.

4. Habitat
 The Environment consists of various
habitats
 A habitat is an ecological or
environmental area that is inhabited by
a particular species of animal, plant or
other type of organism

5. What is a habitat?
A habitat is
any place
where
organisms live
together
naturally.
It is like a
neighborhood
in nature.

6. What does an Organism
need in a habitat?
Shelter Water
Food

7. What about our habitat?
Just like animals and
plants, we need our
own habitat. What
are our needs?
 Shelter
 Food  Water

8. The Ecosystem
 The interrelationships between all living
things and the environment.
 Emphasis is on interdependence of all
things.
 People, nature, and the earth form a
delicately balanced system.

9. The Ecosystem

10. MATTER CYCLING IN ECOSYSTEMS
• For hundreds of millions of years the chemicals
and elements found on Earth have remained
relatively constant, or in other words, they have
changed very little.
• The amount of one element or chemical in the
Earth’s surface is practically the same as it was
many millions of years ago. This consistency is
one of the things that makes life on Earth
possible.

11. Ecological
Cycles
Biosphere
Carbon Phosphorus Nitrogen Water Oxygen
cycle cycle cycle cycle cycle
Heat in the environment
Fig. 3-7, p. 55

12. Nutrient Cycles: Global Recycling
◦ Global Cycles recycle nutrients through the
earth’s air, land, water, and living organisms.
◦ Nutrients are the elements and compounds
that organisms need to live, grow, and
reproduce.
◦ Biogeochemical cycles move these
substances through air, water, soil, rock and
living organisms.

13. The Water Cycle:
Rain clouds
Condensation
Transpiration Evaporation
Precipitation Transpiration
to land from plants
Precipitation Precipitation
Evaporation
Surface runoff from land Evaporation
Runoff from ocean Precipitation
(rapid)
to ocean
Infiltration and Surface
Percolation runoff
(rapid)
Groundwater movement (slow)
Ocean storage
Fig. 3-26, p. 72

14. Water’s Unique Properties
 Water is the elixir of Life
 It is a magical substance which is essential to
the very existence of every life form on earth.
 There are strong forces of attraction between
molecules of water.
 It takes a large amount of energy for water to
evaporate.
 Liquid water can dissolve a variety of
compounds.
 Water expands when it freezes.

15. Effects of Human Activities
on Water Cycle
 We alter the water cycle by:
 Withdrawing large amounts of freshwater.
 Clearing vegetation and eroding soils.
 Polluting surface and underground water.
 Contributing to climate change.

16. The Carbon Cycle:
Figure 3-27

17. Effects of Human Activities
on Carbon Cycle
 We alter the carbon cycle
by adding excess CO2 to
the atmosphere through:
 Burning fossil fuels.
 Clearing vegetation
faster than it is replaced.
Figure 3-28

18. The Nitrogen Cycle:
Bacteria in Action
Figure 3-29

19. Nitrogen Cycle

20. Effects of Human Activities
on the Nitrogen Cycle
 Adding gases (Oxides of Nitrogen) that
contribute to acid rain.
 Adding nitrous oxide to the atmosphere through
farming practices which can warm the
atmosphere and deplete ozone.
 Contaminating ground water from nitrate ions in
inorganic fertilizers.
 Contaminate the lakes and other water bodies
(Eutrophication) by the presence of excess
nitrogen compounds in the ground and surface
water.

21. Effects of Human Activities
on the Nitrogen Cycle
 Human activities
such as production
of fertilizers now
fix more nitrogen
than all natural
sources combined.
Figure 3-30

22. OXYGEN CYCLE

23. The Phosphorous Cycle
Figure 3-31

24. Effects of Human Activities
on the Phosphorous Cycle
 We remove large amounts of phosphate from the earth
to make fertilizer.
 We reduce phosphorous in tropical soils by clearing
forests.
 We add excess phosphates to aquatic systems from
runoff of animal wastes and fertilizers.

25. The Sulfur Cycle
Figure 3-32

26. Effects of Human Activities
on the Sulfur Cycle
 We add sulfur dioxide to the atmosphere by:
 Burning coal and oil
 Refining sulfur containing petroleum.
 Convert sulfur-containing metallic ores into free
metals such as copper, lead, and zinc releasing
sulfur dioxide into the environment.

27. Environmental Pollution
 Pollution is the harmful © Norman R. Rowan/Stock Boston
alteration of our
environment by our own
actions.
 Pollutants – either
unwanted byproducts or
our activities or the
residues of things we have
made, used, and thrown
away.
 Air Pollution
 Water Pollution
 Land Pollution
 Noise Pollution

28. Types of Pollution
 Air pollution
 Most air pollution is caused by the burning of fossil fuels.
 Water pollution
 Disposal of sewage from houses
 Eutrophication
 Infectious agents
 Agricultural wastes
 Organic chemicals
 Inorganic and miscellaneous chemicals
 Sediments from land corrosion
 Radioactive substances
 Waste heat from power plants and industry

29. Types of Pollution—Continued
 Land pollution
 Pesticides – chemicals used to kill insects defined as
pests.
 Herbicides – chemicals used to kill plant life,
particularly weeds.
 Chemical wastes
 Radioactive fallout
 Acid rain
 Garbage

30. A new threat to the Environment /
Planet.
Global warming
 Since the late 1800’s the average global
surface temperature has increased about
0.75 degrees C.
 Most warming has occurred since 1950.

31. Global Warming
There is a gradual increase in
the average temperature of the
Earth’s atmosphere in the last
100 years…It has risen about
1°C since 1900…
• Are human activities
causing global warming?
• What other (non-human)
factors can cause global
warming?
• How does global warming
affect our life?

33. Greenhouse gas are efficient in absorbing IR light…
The most important greenhouse gases are:
H2O – Water vapor.
CO2 – Carbon Dioxide
CH4 – methane
The most abundant greenhouse gas in Earth’s atmosphere
is water vapor. Most of the greenhouse heating of Earth’s
atmosphere is due to Water vapor absorption of IR
radiation emitted by Earth, and then transferring the
energy to the surrounding air molecule

34. Which gas is keeping the Earth warm?
The major natural greenhouse gases are
• water vapor, which causes about 36-70% of the
greenhouse effect on Earth (not including clouds);
• carbon dioxide, which causes 9-26%;
• methane, which causes 4-9%, and
• ozone, which causes 3-7%.
Note that it is not really possible to assert that a
certain gas causes a certain percentage of the
greenhouse effect, because the influences of the
various gases are not additive.

35. So, what’s the big deal if human CO2 causes
1°C temperature increase?
 An increase in atmospheric temperature
(human or natural origin) will lead to the
increase in the water vapor content of the
troposphere.
 Because water vapor is a strong greenhouse
gas, the increase in H2O vapor in turn causes
enhanced greenhouse effect, raising the
temperature more.
 Higher atmospheric temperature will cause
more evaporation of water
 Which leads to even higher temperature…
 Runaway Green House Effect!

36. Global Warming – Is it true?
 Most of the scientists agree that the global
warming observed in the last century were
caused by human activity.
 However, the global climate is a very
complicated system. We understand the basic
principle of the climate system, but we still don’t
understand how nature regulates Earth’s climate
over the long run, nor do we have the capability
to create a realistic climate model and be able to
predict with any certainty the effects of human
activities on our climate system.

37. Ecological footprint
• The ecological footprint is a measure of human
demand on the Earth's ecosystems.
• It compares human demand with planet Earth’s
ecological capacity to regenerate.
• It represents the amount of biologically productive
land and sea area needed to regenerate the
resources a human population consumes and to
absorb and render harmless the corresponding
waste.

38. Ecological footprint
• For 2006, humanity's total ecological footprint was
estimated at 1.4 planet Earths.
• In other words, humanity uses ecological services
1.4 times as fast as Earth can renew them.
• Per capita ecological footprint (EF) is a means of
comparing consumption and lifestyles, and
checking this against nature's ability to provide for
this consumption.
• As per 2006 Calculation UAE has the highest
Ecological footprint in the World (10.68 global
hectare per person).
• For India this value is only 0.91 (See table)

40. Ecological footprint MOVIE
• Currently (As of 2010) the earth have
approximately 1.8 biologically productive hectares
per person.
• Most of the developed courtiers and GCC countries
the ecological footprint is much larger that this.
• That means if every one in the world live like the
people in these countries, we would need multiple
planets.
• The Earth is rapidly depleting in resources and it
has intensified with the rapid development in the
last century.
• The only way to counteract this is to take steps in
reducing your own ecological footprint.

42. Globalization and Environment
• Globalization has transformed the Environmental
issues dramatically.
• Worldwide liberalization of trade may provoke
environmental collapse.
• The major environmental concerns related to trade
are
• the domestic environmental effects caused by
the use of imported products,
• environmental effects caused by the production
of exported goods,
• the environmental effects caused by transport
movements needed for international trade.

43. SAVE THE MOTHER EARTH
 There can be no viable future for humanity without a
healthy planet.
 Earth, water and air support the existence of an immensely
complex living system, powered by the sun.
 We are part of this web of life. But within a few
generations, we are using up most of the earth’s stored
fossil fuel resources and its end products released to the
atmosphere is altering its composition.
 Our globalizing economic system is destabilizing the
planet’s life-support systems, the very systems that support
us and the future generations.

44. THANK YOU