Transcript our environment

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Environment means the surroundings. Land, water, air,
plants, animals, solid wastes and other things that are
surrounding us constitute our environment. Man and
environment are closely intertwined with each other, to
maintain a balance or equilibrium in nature.
Different groups of people working in different areas express
it in various ways. When physical scientists talk about
environment they generally refer to the physical environment
that comprises the three inter locking systems the
Atmosphere, the Hydrosphere and the Lithosphere.
Biologists often refer to biological environment consisting of
all living organisms of the Biosphere. Similarly social
scientists refer to the social, cultural, economic and
organizational environment.
Hence environment may be defined as "the sum of all social,
cultural, economical, biological, physical and chemical factors
surrounding the 'man' to give necessary protection to him."
The natural environment consists of the physical
environment and the biological environment.
 The three major components of the physical
environment are the atmosphere, the lithosphere
and the hydrosphere.
 The are the a biotic or non living components of
the natural environment.
 The physical and the biological environment
undergo changes over time . changes may be
distinctive and sudden ( when an earthquake or
landslide occurs), gradual and noticeable
(population growth), or too slow to be noticed
(mountain building).
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The lithosphere is the outermost, solid surface
layer of the Earth. It is also sometimes called the
crust. The word lithosphere is derived from the
Greek word lithos, which means “stones”.
 The surface of the Earth is not flat. It is uneven,
with different kinds of landforms like mountains,
hills, valleys and plateaus. The crust is covered
by a thin layer of soil which is of vital
importance for life.
 The lithosphere is that realm of the Earth
through which most of the needs of humans are
met.
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The layer of air that surrounds the Earth is called
the atmoshphere. The atmosphere is a mixture of
gases, dust and water vapour. The word atmosphere
is derived from the Greek word atmos, which means
‘vapour’. The gravitational force (the ability of a body
to pull or attract everything around towards itself)
of the Earth holds atmosphere around it.
The atmosphere is useful to humans in different
ways.
It provides the life-giving gas oxygen. We inhale
oxygen and exhale carbon dioxide.
It acts as a blanket and keeps the Earth warm by
trapping the hear that radiates from the Earth(
terrestrial radiation).
It protects life from the harmful rays and the
scorching heat of the sun.
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Hydrosphere (derived from the Greek word by
dor, meaning water) refers to the water on the
Earth. The earth is called the blue planet because
71% of its surface is covered with water and only
29% with land. Water is found as solid ice in
glaciers and ice sheets. It is found as liquid water
in oceans, rivers, lakes, ponds and underground
streams. It is also found as water vapour in the
atmosphere . water moves continuously from one
form to the other; this movement is called the
water cycle.
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The biosphere is the narrow zone of contact between
land(lithosphere),water
(hydrosphere)
and
air
(atmosphere),where life forms exist. It is also called
the living world or the biological environment.
Everything in the biosphere is interconnected and
interdependent.
Forests provide products like timber, fruits, nuts,
resins, lac and medicinal herbs.
They also provide a natural habitat for various plants
and animals.
Forests help moderate atmospheric temperature by
absording carbon dioxide and adding moisture to the
air through transpiration.
Many animals depend on forests and grasslands for
their food.
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Have you ever wondered why there are cone shaped trees
and animals with long fur, like the yak, in ladakh, and not
in Mumbai or Delhi? Why are camels found in Rajasthan
and penguins in Antarctica? This is because plants and
animals have their own typical habitats to which they have
adapted themselves. They live like a community and they
depend on each other and on their immediate physical
surroundings. In fact, everything in the natural
environment is connected. The natural environment consist
of several interconnected ecosystems.
An ecosystem is a community of living things and nonliving components that work together. Ecosystem have no
particular size. An ecosystem can be as large as a
rainforest, or as small as a pond. Grasslands, costal
(oceanic) areas, mountains, deserts, lakes- all have their
own unique ecosystem.
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The human-made environment is that which is created when human
beings interact with the natural environment. It consists of the built
environment, which includes buildings, railway tracks and bridges;
and the socio-cultural environment, which includes family, school and
college, community, country, religion, music and dance and cinema.
Human beings adapt themselves to the natural environment by
making modifications in their shelter, food and clothing. They also
modify the natural environment to suit their social, biological,
economic and cultural needs.
People who live in hot, wet coastal areas like karalla or coastal
Odessa traditionally eat rice and fish. They also wear cotton clothes
which keep them cool, and live in houses with sloping roofs so that
rain can run off easily.
People who live in the icy reaches of ladakh wear woolen, clothes,
and traditionally eat food based on barley and wheat. People who live
in places like Punjab and utter Pradesh, which have very cold winters
and hot summers, dress and eat according to the season. Food during
winter includes items that are energy giving, such as til(sesame),
groundnut, jaggery, mustard oil, etc.
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Human also change their environment to suit their needs.
The early humans slept on trees and caves and foraged
for their food. With the passage of time, humans started
changing the natural environment to their advantage
with the help of varied skills and technologies. They
started building houses to live in. they discovered
minerals and invented machines. The growing population
and increasing demand for goods resulted in rapid
industrialization and mass production.
To satisfy their ever increasing wants, the natural
environment is being exploited indiscriminately by
humans. This is leading to environmental degradation.
Environment degradation is the process by which the
environment is increasingly polluted, overexploited and
destroyed.