Page 118 - SST Class 07

The imbalances have been created not only by
the adverse happenings, but also because of
growing demands on nature and natural
resources. It may be interesting to note that origin
of human species on the earth is quite recent. For
major part of his existence man lived in forests
and was very much a part of nature. After
civilizations developed, man began to exploit
natural environment for his own use. Just in the
last the few centuries, environmental degradation
took place and in the last few decades, it is Environment Degradation
manifesting itself in many ways. One such resulted in interference in many of the natural
prominent consequence is global warming which processes. On account of these imbalances, the
may raise the mean temperature of the earth by warnings like ‘our environment in danger’ have
few degrees. The implications of this imbalance been issued.
are many. For example, disappearance of glaciers
and a rise in sea level. It may result in drying up
12% of birds, 23% of mammals, 25% of conifers and
of many rivers and pose many problems to
32% of amphibians of the world are on the verge of
human settlements. These imbalances have
extinction.

Terminology

Dwellings : a house, flat or other place of residence
Autocratic : relating to a ruler who has absolute power
Biodiversity : the variety of plant and animal life in the world or in a particular habitat
Exploit : make full use of and derive benefit from
Interference : the action of interfering or the process of being interfered with
Extinction : the state or process of being or becoming vanish

Inside Story
Inside Story
g The earth is the home of all living beings.
g The environment of the earth supplies the basic necessities for life and supports large
number of life forms.
g The landforms are being modified by various natural and human activities.
g Changes in environment were responsible for the evolution of human beings about one
million years ago.
g The environment link on the earth between its three spheres – lithosphere, hydrosphere and
atmosphere, is explained by the biosphere.
g A perfect balance is necessary between the natural and man-made environment.

g After civilizations developed, man began to exploit natural environment for his own use.

Social Science-7 118