Environmental science is the systematic study of our environment- natural and human, and our proper place in it. Since the conditions of both worlds affect individual and community, they are essential to our lives, and constitute important components of the environment. It is essentially an inter-disciplinary approach that brings about an appreciation of changes in our natural and built environment. As an applied science, it seeks to provide answers- practical solutions, to the complex problems of how to make human civilization sustainable within the carrying capacity of the global ecosystems.
Introduction
Environmental science is the systematic study of our
environment- natural and human, and our proper place in it. Since the conditions of both worlds affect individual
and community, they are essential to our lives, and constitute important
components of the environment. It is essentially an inter-disciplinary
approach that brings about an appreciation of changes in our natural and built
environment. As an applied science, it seeks to provide answers- practical
solutions, to the complex problems of how to make human civilization
sustainable within the carrying capacity of the global ecosystems. This is why,
it is not just a mere collection of facts about the environment; it is also
about the way we all should live. It provides information about the environment
at large, but it is expected that this will lead to a concern for your own
environment. It is hoped that you will begin to act at your own level to
protect the environment. As an inter-disciplinary subject, it draws from many
fields of inquiry to help us to understand the planet Earth in which we live,
and our appropriate role in it. The most amazing feature of our spaceship Earth
is the self-sustaining ecological systems that make life possible for all
living beings. In spite of many problems that surround us, the earth is
resourceful. However, unprecedented population growth, food shortages, resource
scarcity such as energy supplies, air, water and soil pollution, destruction of
habitat, loss of biological diversity all poses a serious threat to the
carrying capacity of our ecosystems. We realize that these problems encompass
our entire planet and require global cooperation to find workable solutions.
For example, infant mortality rate has declined in many places. Perhaps we can
extend these achievements to other areas. Moreover, we have to develop a
genuine interest in conserving natural resources and protecting environment.
There are also ethical reasons to believe that nature has a right to continue
to exist for its own sake.
The
term 'environment' is derived from the French word ‘Environer’, which
etymologically means to encircle. The dictionary meaning of the term
‘environment’ is a surrounding- which denotes the sum total of external factors
or conditions- physical, biological and cultural- that directly influence the
survival, growth, development, and reproduction of organisms (people, plants,
animals, and the microbes) present in a
particular area. Literally, everything that surrounds us may
collectively be termed as the environment e.g. the air which we breathe, the water which we drink, the land on
which we stand, and the soil that supports plant growth and from which we get
food. Environment is, thus, may be
defined as “the sum total of land, water and air and the interactions that
exists among them and with their living communities including man, plants,
animals and microbes”.
The Encyclopedia Britannica (1993) defines environment
as “the complex of physical,
chemical, and biotic factors that act upon an organism or an ecological
community and ultimately determine its form and survival". Natural
scientists have regarded environment as a set of independently present objects
and processes. Attention has been given increasingly to the importance of
natural cycling of chemical elements, and the effects of human intervention.
The theme that the environment denotes- the natural surroundings of human
society and the environmental crisis arises from the deliberate manipulation of
that external surroundings- has received due attention. Admittedly, the term
environment has an essentially relational meaning and that an environment
without organisms is not meaningful. Further, since the term 'environment' has
often been used in composite sense, it leads to five fundamental questions:
What is surrounded? When surrounded? Where surrounded? How surrounded? Why
surrounded? Decidedly, the answer to the first question (What) is living object
under investigation in general, and man in particular. If man is taken to be
surrounded, time become the answer to the second question (When); spatial locational
attributes (area or habitat) provide answers to the third question (Where)-
this is environment. How and why questions are just the processes and
explanations of the environment.
According
to Park (1980), "environment refers to the sum total of conditions
which surround man at a given point in space and time". The time
dimension is important because the environment for any living organism has
never been so constant or static; it has always been changing- slowly or
rapidly. In further clarifying
the factors, conditions or circumstances that surround an organism or group of
organisms, we essentially come up with two environments: natural (bio-physical)
and human (socio-cultural) worlds. The natural world consists of
all biotic (living) and abiotic (physical or non-living) elements
including the energy component-
solar radiation (sun light) and geothermal energy. The biotic component consists of flora (plants) and fauna (animals) including human beings
and microorganisms. The abiotic
component comprises of
solid, liquid and gaseous state of the planet Earth representing the
lithosphere (solid earth/land- soil and rocks), the hydrosphere (water domain)
and the atmosphere (air realm) respectively, that preceded human beings by
billions of years, and of which we are a part. These may be further divided into sub-categories or smaller units such as
mountains, plain lands, valley, oceans, lakes, rivers, coasts, deserts etc.
environments. The physical environment may also be viewed in terms of climatic
conditions providing a certain suits of habitats for biological communities
such as tropical, temperate and polar environments. These may even have fused
together to form 'biome environment' like tundra, temperate and tropical
biomes. While such a classification is arbitrary, it helps in organizing and
extending our knowledge of the distribution and flow of materials or nutrients
into the components. Natural environmental systems operate through
self-regulating mechanisms- homeostatic, i.e. any change in natural ecosystems
bring about by natural process is counter balanced by changes in other
components of the environment. The socio-cultural world includes
the complex of social or cultural conditions that affect an individual or
community. It may also be called the human world or the world of social
institutions and artifacts that we create for ourselves (to suit our purpose by
increasing facilities, amenities and convenience) using science, technology and
political organization.
In
fact, environment is an inseparable entity which is constituted by the
interacting systems of physical, biological and cultural elements that are interlinked
individually and a well as collectively in myriad ways. Accordingly,
the term environment should be considered to embrace as a holistic view of the
world, which functions dynamically with a multitude of bio-physical components
and socio-economic systems, distinguished by their attributes and quality of
spatial organization (geographic space) including the mode of behaviour of
biotic and abiotic elements. As such,
an environment is the "aggregate
of all external factors or conditions (both natural and man-made) which
influence the activities and existence of all living things including
man".
Man-Environment Relationship
Natural environment is that part of the planet Earth
which is relatively untouched by man (not invaded remarkably as yet). From a
historical context of the areas where we live, we would see that our
surroundings were originally a natural landscape such as a forest, a river, a
mountain, a desert, or a combination of these elements. But it is difficult to
find any virgin environment of such type that has not been approached by man.
Most of us now live in landscapes that have been profoundly modified (e.g.
village, towns or cities) by human actions. But even those of us who live in
urban areas must get our food supply from surroundings and these, in turn, are
dependent on natural landscapes for resources such as food grains, fruits and
vegetables, water, fuel fodder, and fish. Thus, our daily lives are
inextricably linked with our surroundings and inevitably affect them. For
example, we breathe air, use resources from which food is made, use water to
drink and for other day-to-day activities- household, industrial and
agricultural, and we depend on the community of living plants, animals and
microbes which form a web of life, of which we are also a part. Everything that
surrounds us forms our environment and our lives depend on keeping its vital
system as intact as possible. Our dependence on nature is so great that we can
not continue to live without protecting the Earth’s natural resources. In the
past (ancient times), people were confined within their narrow environmental
limits and had fixed capability to alter their surroundings. But, today we have
power to extract and consume more resources, generate more wastes, and modify
our world the way we would like it to be- mostly in ways that threaten both our
continued existence and that of many organisms with whom we live.
It may
be pointed out that of all the organisms, man is found to be the most
intelligent, skilled, organized and civilized The three distinct aspects of man
i.e. physical, social and economic have different characteristics and
functions. Physical man belongs to a
biological community and thus requires basic elements of natural environment
i.e. shelter (habitat), air, water and food like other biological species for
their survival. Social man
establishes social institutions, forms social organizations, formulate
policies, principles and laws to safeguard his existence, interest and welfare.
Economic man derives and utilizes
resources from the environment with his skills and technologies to make his
life better. Further, the environment for any living organism including man has
never been so constant or static. It has always been changing- sometimes
slowly, sometimes rapidly or drastically. Every living species of plants and
animals influences its environment and, in turn, are influenced by it. Human
beings also are particularly influenced and affected by these changes. However,
with increasing scientific knowledge, man is able to modify his immediate
environment to suit his basic needs more than any other organisms. This enables
human beings to improve the quality of his life. However, today human beings
are more equipped with a variety of skills and superior technology which have
ruined the natural environment without understanding the repercussions even on
their own existence. Environmentalists have alarmed the modern man against the
devastating impacts of unscientific and reckless exploitation of natural resources
and the environment, and pleaded to save the life on earth. Numerous issues
that have been raised on quality of the environment and ecological imbalance
are as follows.